Morning Glory Blooming Season and Bud Midge Control Medication Methods
Morning glory, many people like to grow it, and when it blooms it really looks like a big trumpet. What season does morning glory bloom in? What medication kills bud midges: What season does morning glory bloom in: Morning glory generally has a flowering period from June to October. Morning glory usually blooms at 4 or 5 o'clock in the early morning
Morning glory, many people like to grow it, and when it blooms it really looks like a big trumpet. What season does morning glory bloom in? What medication kills bud midges:
What season does morning glory bloom in:
Morning glory generally has a flowering period from June to October. Morning glory usually blooms at 4 or 5 o'clock in the early morning, and by around noon the flowers have withered. This is because morning glory flowers are large and thin, and the flowers contain abundant water; when sunlight hits them, the water in the flowers evaporates dry within a relatively short time. If in a cool place, morning glory wilts more slowly, and sometimes the flowers are still open even in the afternoon.
What medication kills bud midges:
At the bud stage, choose jia di fen, diazinon granules, etc., mix evenly with fine soil, and broadcast on the soil surface of the tree basin; once every 7 days, for 2-3 consecutive times; when the flower buds are 2-3 mm in diameter (when they turn white), choose sulfur phosphorus, trichlorfon, etc. to spray the tree canopy; remove damaged flower buds as early as possible, and bury them deeply in a concentrated way or boil them; in winter, deeply turn the garden soil to eliminate some overwintering pest pupae.
That is all for the introduction to the season when morning glory blooms. Pay attention to the medication for bud midges.
Complete Guide to Home Flower Planting Techniques and Key Points for Home Flower Growing
With their gorgeous elegance, flowers decorate nature with extraordinary beauty and give people the enjoyment of beauty. Growing flowers can enrich and adjust people's cultural life, add pleasure, cultivate temperament, improve health, and also increase scientific knowledge and improve cultural and artistic literacy, and they also have many important economic values. Below let us take a look at the complete guide to home flower planting techniques!
The "Three Suitables" of Home Flower Growing
1. Suitable to grow flowers with strong toxin-absorbing ability: Some flowers can absorb certain concentrations of toxic gases in the air, such as sulfur dioxide, nitrogen oxides, hydrogen fluoride, formaldehyde, hydrogen chloride, etc. Wintersweet can absorb mercury vapor, pomegranate plants can absorb lead vapor in the air, snapdragon, canna, morning glory, gladiolus, dianthus, etc. can convert highly toxic sulfur dioxide into non-toxic or low-toxicity sulfate compounds through oxidation via their leaves, narcissus, four-o'clock, chrysanthemum, saxifrage, etc. can convert nitrogen oxides into proteins in plant cells, and spider plant, aloe, snake plant can absorb large amounts of indoor pollutants such as formaldehyde.
2. Suitable to grow flowers that can secrete bactericides: The bactericides secreted by flowers such as jasmine, lilac, honeysuckle, and morning glory can kill certain bacteria in the air, inhibit the occurrence of diphtheria, tuberculosis, dysentery pathogens, and typhoid bacteria, and keep indoor air clean and hygienic.
3. Suitable to grow flowers with "complementary" functions: Most flowers mainly carry out photosynthesis during the day, absorbing carbon dioxide and releasing oxygen, and carry out respiration at night, absorbing oxygen and releasing carbon dioxide. Cacti are just the opposite, releasing carbon dioxide during the day and absorbing carbon dioxide and releasing oxygen at night. Growing flowers with "complementary" functions in the same room can not only allow the two to benefit each other, but also balance the indoor oxygen and carbon dioxide levels and keep indoor air fresh.
The "Three Avoids" of Home Flower Growing
1. Avoid growing too many flowers that give off strong fragrance and irritating odors: Orchids, roses, Chinese roses, lilies, night-blooming jasmine, etc. can all give off rich aromas. One pot in a room fills it with fragrance, but if too many fragrant flowers are placed indoors and the scent is too strong, it will excite people's nerves, and especially if people smell it for a long time in the bedroom, it can cause insomnia. The gases given off by poinsettia and Chinese evergreen are harmful to people, and prolonged contact with the microparticles released by tulips and hydrangea can cause skin allergies and itching.
2. Avoid placing too many: At night most flowers release carbon dioxide and absorb oxygen, "competing for air" with people, while at night most bedrooms are closed and air circulation with the outside is insufficient. If too many flowers are placed indoors, it will reduce the indoor oxygen concentration at night and affect the quality of sleep at night, such as chest tightness and frequent nightmares.
3. Avoid placing toxic flowers indoors: For example, oleander is toxic in its stems, leaves, and even flowers in spring, summer, and autumn, and the milky white sap it secretes contains oleandrin, which can cause poisoning if ingested by mistake. The bulbs of narcissus contain lycorine toxin; if a child eats them by mistake, it can cause symptoms such as vomiting, and the sap of the leaves and flowers can cause skin redness and swelling, and if the sap gets into the eyes by mistake, it can harm the eyes. Too much contact with mimosa can easily cause sparse eyebrows and yellowing hair, and in severe cases cause hair loss.
The "Six Don'ts" of Home Flower Growing
1. Being careless: Flowers, like people, are living things and need careful care. Many flower growers lack the care and diligence they should have toward these beautiful lives. First, they are mentally lazy and do not like to study flower-growing knowledge, are content to remain laymen for a long time, and manage things improperly. Second, they are lazy with their hands and are unwilling to spend too much time and energy on flowers. After the flowers enter the home, they are left aside and ignored, enduring hunger and thirst for a long time and suffering from pests and diseases. In this way, even the best flowers will gradually wither, so lazy people cannot grow flowers well.
2. Loving them too much: Contrary to the above situation, some flower growers love flowers too much and their hands itch if they do not fiddle with them for a moment. Some water and fertilize without any regularity, watering whenever they think of it, causing flowers to die from excessive waterlogging or fertilization. Some casually move flower pots around, moving them to several places in one day, making the flowers constantly adapt to the environment and disrupting normal growth patterns. If this continues, it would be strange if the flowers were not tormented to death.
3. Chasing fame and profit: Some flower lovers believe that when growing flowers, one should grow famous flowers, because famous flowers have high ornamental value and great market profit. Under the control of this mentality, they spare no expense and seek to buy famous flowers and trees everywhere. As a result, due to lack of good maintenance conditions and management techniques, the flowers often die soon after purchase, which both wastes precious famous flowers and wastes money. This is a conceptual misunderstanding. The correct approach should be to start with ordinary, lower-grade varieties, gradually explore the rules and techniques of flower growing, and after reaching a certain technical level, gradually purchase more precious varieties. Only then is success more likely.
4. Not distinguishing good from bad: Some flower growers enjoy being greedy for size and completeness and bring home whatever variety they see. This not only makes management more difficult, but also brings some unsuitable flowers into the home, polluting the environment and harming health. For example, flowers with toxic sap can easily cause poisoning when people come into contact with them. The smell of some flowers affects the human nervous system and can easily cause breathing difficulty and even allergic reactions. In short, home flower growing should not be greedy for size and completeness or fail to distinguish good from bad. One should choose varieties with smaller plant shapes, beautiful appearance, and no harm to the human body.
5. Being fickle: Some flower growers are restless and have no theme in growing flowers. The flowers at home are changed as quickly as a revolving lantern, which is a great taboo in flower growing. First, changing varieties too quickly and growing them for too short a time is not conducive to cultivating flowers and trees with graceful plant shapes and high ornamental value. Second, tasting each kind of flower only superficially is not conducive to improving one's flower-growing level, and in the end one is still a flower novice. Therefore, only by choosing one or two kinds of flowers and focusing on studying and cultivating them can a flower grower gain something in their heart.
6. Not having new concepts: Today, new knowledge and new technologies in the flower-growing industry emerge endlessly, but most flower growers still stick to traditional maintenance methods and are not good at using new technologies and new equipment in aspects such as the use of flower containers, water and fertilizer management, and seedling cultivation, such as soilless cultivation, odorless flower fertilizer, and various flower containers. As a result, home flower growing is unhygienic, unattractive, not novel, and has relatively large side effects.
Spring Care of Home Potted Flowers
1. Propagating good seedlings: Chinese rose, geranium, pomegranate, winter jasmine, etc. can be propagated in spring by cutting robust branches. Rhododendron and jasmine prefer acidic soil, so sturdy new branches 5-10 cm long can be cut, the lower leaves removed, and 3-4 top leaves kept for cutting. For cutting, black mountain soil, vermiculite, or yellow sand can be used as the medium. The cuttings should be sprayed moderately to maintain a certain humidity, and generally they can take root after about 1 month. Orchids, agave, and spider plant can be propagated in early spring by division or by stolons respectively. Spring-sown herbaceous plants grown from seed, such as asparagus fern, five-color pepper, mimosa, garden balsam, scarlet sage, morning glory, and Tagetes species, can be broadcast sown or sown in holes.
2. Repotting and changing soil: Repotting and changing soil is a method of supplementing fertilizer for potted flowers in spring. Generally, small pots are repotted once a year, and large pots once every 3-4 years. Tall plants need larger pots. Some plants whose root systems grow too densely or that have dead roots or rotten roots need appropriate pruning. After repotting, generally the first watering should be thorough, then the plant should be placed in a cool place. Afterward, water again when the pot soil is seen to be dry. Generally, after new roots grow, carry out normal watering and move the plant to a sunny place.
3. Pruning and trimming: Pruning and trimming should be carried out according to different plants. Rhododendron and winter jasmine should not be pruned excessively. For pomegranate, Chinese rose, etc., dead branches, injured branches, or overly dense branches can all be cut off in early spring to promote abundant flowers and lush leaves. Jasmine should have old leaves removed when repotting to encourage more new branches to sprout. Vine and climbing plants such as Boston ivy, banks rose, wisteria, and rose can be pruned so that the leaf surface receives as much sunlight as possible and grows vigorously.
Note: In early spring, potted flowers should not be moved outdoors too early, so as to avoid cold air invasion and cold damage. Watering can be increased as the temperature rises, and keep dryness and moisture balanced.
Summer Care of Home Potted Flowers
1. Water timely: In summer, flowers have luxuriant branches and leaves and consume much water, so in summer, flowers should be watered sufficiently every morning and evening.
2. Build frames for shade: For all potted flowers, as soon as summer arrives, a frame should be built and reed curtains placed on it for shade, so that they can safely pass through the intense summer heat.
3. Pay attention to ventilation: For indoor flowers, when the temperature exceeds 30°C, attention should be paid to ventilation. Open the windows and let fresh air flow into the room to prevent heatstroke and lower the temperature.
4. Moisturize and cool: In summer, some grass can be placed over the pot soil so that sunlight does not shine directly on the pot soil, thereby lowering the temperature of the pot soil and also preventing the moisture in the pot soil from evaporating too quickly. A sprayer can also be used to wet the leaves of the flowers, and at the same time wet the surroundings to lower the temperature and increase humidity. This is very beneficial to some flowers that like coolness.
Autumn Care of Home Potted Flowers
1. Add water and fertilizer management: After the Beginning of Autumn, the weather gradually turns cooler. For some foliage flowers such as asparagus fern, spider plant, and sago palm, generally apply a dilute liquid fertilizer once every half month to keep the leaves green and improve cold resistance. For chrysanthemum, camellia, rhododendron, etc. that bloom once a year, it is necessary to apply liquid fertilizer mainly based on phosphorus fertilizer in time to ensure sufficient nutrients so that they bloom more and larger. For Chinese rose, Milan, jasmine, etc. that bloom multiple times a year, sufficient fertilizer and water should be supplied so that they bloom continuously. For some ornamental fruit flowers, such as kumquat, finger citron, and fruiting pomegranate, 1-2 applications of dilute liquid fertilizer mainly based on phosphorus fertilizer should be applied.
2. Sow in autumn in time: Autumn cuttings. In autumn, mature flower and tree seeds should be harvested in time, and tulips, gloxinia, snapdragon, etc. should be sown in time. Especially for seeds that easily lose germination ability, they should be sown in time in autumn, and combined with pruning, flower trees should be cut. For example, cutting Chinese rose, rose, and banks rose has a relatively high survival rate.
Winter Care of Home Potted Flowers
1. Overwintering of deciduous woody flowers: Most deciduous woody flowers originate from temperate regions. Common ones include pomegranate, honeysuckle, Chinese rose, ornamental peach, and winter jasmine. They are generally in a dormant state in winter, so the room temperature can be controlled at about 5°C. If there is a balcony or small courtyard, cold-hardy potted Chinese rose, ornamental peach, pomegranate, honeysuckle, etc. can be placed together in a wind-sheltered place on the balcony or in a corner of the courtyard, wrapped and covered with plastic film, and they can overwinter safely.
2. Overwintering of evergreen woody flowers: Such as oleander, kumquat, osmanthus, etc., which are in a semi-dormant state. The temperature is generally controlled above 0°C, and they can safely pass the severe winter. For Milan, jasmine, hibiscus, and gardenia, they should be placed in places with sufficient sunlight. The indoor temperature should be kept at about 15°C. If the temperature is too low, it will cause the flowers to die.
3. Overwintering of annual and biennial herbaceous flowers: Such as fairy primrose, coleus, calceolaria, etc. Keeping the room temperature between 5-15°C allows normal growth. For perennial herbaceous flowers such as asparagus fern, garden balsam, geranium, and wax begonia, keeping sufficient sunlight and a room temperature of 10-20°C allows them to grow well. For herbaceous flowers in a dormant state in winter such as clivia and oncidium, maintaining a room temperature of about 5°C and giving an appropriate amount of light is enough. Daily light should not exceed 8-10 hours. At the same time, strengthen fertilizer and water management, and after two months they can bloom.
What Particulars Are There in Water for Watering Flowers
1. Water selection: The best water for watering flowers is neutral or slightly acidic river water, pond water, or rainwater. Rainwater is best for watering flowers because rainwater contains more natural minerals. Next is river water and pond water. In particular, greenish pond water is rich in nutrients and is relatively ideal for watering flowers. In cities, tap water is often used for watering flowers, but tap water contains relatively high levels of bleaching powder and chemicals, so when using it to water flowers, it should be stored for one or two days first. In addition, if a few slices of vitamin C are put into tap water, the chlorine in the water can be eliminated. Generally, add one slice per basin of water, and after half a day it can be used to water flowers.
2. Temperature control: Flower proverb says: "When southern flowers move north, add alum when watering", "When growing southern flowers at home in the north, fish tank water is better for watering", "Fish water is fat and rice water is strong, most suitable for watering potted flowers." Whether in severe winter or midsummer, do not use cold water to water flowers. When the temperature is below 10°C, an appropriate amount of hot water can be added to the water to make the water temperature as close as possible to the soil temperature, creating a microclimate suitable for flower growth.
How to Judge Whether Potted Flowers Are Short of Water?
1. Tapping method: Gently tap the upper and middle part of the flowerpot wall with the knuckle of a finger. If a relatively crisp sound is produced, it indicates that the pot soil is already dry and needs immediate watering. If a dull, muddy sound is produced, it indicates that the pot soil is moist, and watering can be temporarily omitted.
2. Visual method: Observe with the eyes whether the color of the pot soil surface has changed. If the color becomes lighter or appears light gray-white, it indicates that the pot soil is dry and needs watering. If the color becomes darker or appears dark brown, it indicates that the pot soil is moist, and watering can be temporarily omitted.
3. Finger-testing method: Gently insert a finger about 2 cm deep into the pot soil and feel the soil. If it feels dry or rough and hard, it indicates that the pot soil is dry and needs immediate watering. If it feels slightly moist, fine, and soft, it indicates that the pot soil is moist, and watering can be temporarily omitted.
4. Pinching and twisting method: Pinch and twist a bit of the pot soil with the fingers. If the soil becomes powdery, it indicates that the pot soil is dry and should be watered immediately. If the soil forms flakes or granules, it indicates that the pot soil is moist, and watering can be temporarily omitted. The above methods are all based on experience, and they can only tell people the approximate condition of the pot soil's dryness and moisture. If you need to know the degree of dryness and moisture of the pot soil accurately, you can buy a soil moisture meter and insert it into the soil, and then you can see words such as "dry" or "moist" on the scale, so you can know exactly when to water.
Homemade Fertilizer for Home Potted Flowers
1. Soaking liquid fertilizer: Use a small vat (or small jar) and put in waste vegetable leaves, melon and fruit peels, chicken and fish offal, fish scales, waste bones, eggshells, and moldy foods (peanuts, melon seeds, beans, bean powder), etc., add water and sprinkle a little trichlorfon, then cover tightly. After high-temperature fermentation and decomposition, it can be used. When using, take the supernatant liquid and dilute it with water before trial use. The above waste can also be mixed with some old potting soil, add some water, put into a large plastic bag, tie it tightly, leave it for a period of time, and use after fermentation.
2. Waste composting: Choose a suitable place and dig a soil pit 60-80 cm deep, line 10 cm of furnace ash at the bottom, put rotten vegetable leaves, poultry and livestock viscera, fish scales, chicken and duck manure, eggshells, meat waste, and broken bones into the pit, sprinkle some insecticide, cover with a layer of garden soil about 10 cm thick, and keep the pit moist to promote fertilizer decomposition. It is best to compost in autumn and winter. When it warms up and decomposes in spring with no foul odor, it can be mixed into potting soil as base fertilizer. It can also be sieved while moist with a 4 mm sieve and rubbed into granules: the fine part is used as topdressing, and the coarse part as base fertilizer. When composting, some orange peel or diluted rice vinegar can be added to reduce the odor.
Clever Fertilization for Home Flower Growing
1. Timely fertilization: So-called timely fertilization means applying fertilizer when flowers need it. When it is found that flower leaves become lighter or yellow and the plant grows thin and weak, that is the most suitable period for fertilization. In addition, when flower seedlings sprout leaves and branches unfold leaves, topdressing should be applied to meet the fertilizer demand for rapid seedling growth. Different growth stages of flowers also have different fertilizer needs. The type and amount of fertilizer applied also differ. For example, applying more nitrogen fertilizer at the seedling stage can promote seedling growth, and applying phosphorus fertilizer at the bud stage can promote larger, more vivid flowers and a longer flowering period.
2. Appropriate amount of fertilization: Fertilization for potted flowers should achieve "eat small meals often", that is, fertilize many times and apply a small amount each time. Generally, apply dilute fertilizer water once every 7-10 days, and once every 15-20 days after the "Beginning of Autumn". As flowers and trees gradually grow, the fertilization concentration gradually increases. For example, the application concentration of urea gradually increases from 0.2% in the earlier period to 1.0%, and phosphorus and potassium fertilizer increases from 1.0% to 3.0-4.0%.
3. Seasonal fertilization: In spring and summer, flowers grow quickly and vigorously, so more fertilizer can be applied appropriately. After autumn begins, the temperature gradually decreases, flower growth weakens, and less fertilizer should be applied. From late August to early September, fertilization should be stopped to prevent a second growth peak, otherwise it is easy to make flower tissue cells tender and cause difficulty in overwintering. For overwintering flowers, fertilization should be stopped when they are in a dormant state in winter.
4. Temperature control: Potted flowers should not be fertilized around noon in high temperatures or on rainy days. Fertilizing at this time easily damages roots. It is best to fertilize in the evening. After autumn and in winter, when the temperature is low, flowers grow slowly and generally are not fertilized. In summer, when the temperature is high, flowers grow vigorously and more fertilizer should be applied. When the temperature is high, the concentration of topdressing should be low and the amount should be small. When using dilute fertilizer water for topdressing, apply it more times.
5. Mixed application of chemicals and fertilizer: If pests or diseases occur during fertilization, an appropriate amount of chemicals can be added to the fertilizer liquid, which can play the dual role of fertilizing and preventing pests and diseases.
Why Do Home-Grown Flowers Die?
1. Too much fertilization: Some people love flowers deeply and, considering that potted flowers consume many nutrients during the flowering period, apply large amounts of chemical fertilizer, causing excessive concentration. In mild cases, this affects the absorption of water by root hairs; in severe cases, it causes the plant to die.
2. Too much unmatured organic fertilizer applied: Because organic fertilizer has large amounts of microbial activity when decomposing in the soil, it causes soil oxygen deficiency, and the roots suffocate and die. On the other hand, organic fertilizer fermentation produces substances such as alcohol and lactic acid that are toxic to the root system, and fermentation releases a large amount of heat, raising the temperature and causing "root burning".
3. No place for growing flowers: People often put potted flowers on enclosed balconies facing east or west. In this way, due to the radiant heat of the sun, the temperature inside the balcony rises sharply, forming a hot and dry environment. High temperature, dryness, and lack of ventilation also make red spider mite damage likely, accelerating the death of flowers.
4. Overwintered flowers suddenly taken outdoors: Leaves grown by flowers overwintered indoors belong to semi-shade leaves or shade leaves. If suddenly taken outdoors in early spring, shade leaves cannot adapt, and tender leaves and tender buds are easily burned by sunlight. In addition, the temperature difference between indoors and outdoors is relatively large, which easily causes fatal damage to flowers.
5. Lack of sunlight: Some people, for convenience of appreciation, place flowers on indoor tables, far from sunlight, causing their photosynthesis to be inhibited. The organic nutrients in the flowers can only be consumed and cannot be replenished in time, reducing the flowers' resistance and causing the plants to weaken and die. Watering too much and too frequently is also a cause of plant death.
Complete Guide to Orchid Cultivation Techniques
"Three parts planting, seven parts care." This is the ancients' experience in growing orchids. Whether care is good or bad determines whether orchids flourish and whether they can bloom, so it makes sense that predecessors attached great importance to this. Below is a specific introduction to methods for caring for and managing orchids.I. Location
The location where orchids are placed is very important, as it directly affects the growth and development of orchids. Orchids are generally placed in the open in spring, summer, and autumn (in a shaded open area in summer), and indoors in winter. Outdoors, it is best if the surroundings are open and the air is moist. Indoors, there should be sufficient light, preferably facing south. In this way, it is beneficial to orchid growth. Orchid pots are best placed on wooden racks or tables, not on the ground.
II. Shading
Orchids mostly belong to semi-shade plants, and most species are afraid of direct sunlight, so appropriate shading is needed. In early and mid-April, orchids can receive more sunlight to promote growth. After late April, appropriate shading is needed. For summer orchids and autumn orchids with upright leaves, it is best to place them on the south side of a shaded area so they receive a suitable amount of sunlight; for drooping-leaf autumn orchids and spring orchids, receiving two hours of light per day is best. From the beginning of June to September, shade should be provided earlier each day. For example, if reed curtains are used, dense curtains or two layers of sparse curtains can be used. After October, the weather turns cooler and sunlight is weaker, so shading can be delayed, but around noon, attention still needs to be paid to shading.
III. Rain Protection
Orchids can tolerate light rain, but must avoid plum rains, showers, or continuous rain. During the plum rain season, rain protection work must be done especially well. From late June to mid-September, there are often showers. If the rain time is short and the rainfall is also small, more water should be given in the evening to let the hot air in the pot escape; otherwise orchids will be damaged, and may even have root rot and die. If a shower is followed by sunshine, shade should be provided in time to prevent heat rising from the ground from affecting orchid growth. The rainy season coincides with the stage when orchids send out leaf buds. If the pot soil is too warm, it will cause poor leaf bud growth or invite disease. At this time, a small amount of plant ash can be sprinkled to regulate the moisture of the pot soil.
IV. Watering
The flower proverb says: "Dry orchids, wet chrysanthemums." This saying has some truth. Generally speaking, orchids are best kept at eight parts dry and two parts moist. If too moist, the flowers easily rot at the roots and die. The principle of watering should be: water when dry, stop when moist, and appropriately lean dry. In specific handling, generally attention should be paid to: during the growth period (May to the end of June), water appropriately more; during the leaf bud stage (about March-April) and flowering period (about March-April), water appropriately less; during the dormant period (winter), water even less or not at all. If the flowerpot is large and the orchid plant is small, water less; if the pot is small and the plant is large, water more. In hot and dry weather, water appropriately more; in cool and humid conditions (such as the plum rain season), water less or not at all. For orchids newly dug from the mountains, if the root system is sparse or many roots are broken, water less and keep the pot soil a bit dry; this will prevent root rot and help new leaves emerge. The ancients' experience of "not dry in autumn, not wet in winter" is a very good summary of how to water spring orchids and summer orchids. However, in some northern regions, because the climate in winter and early spring is too dry, orchids should not be made too dry either. Watering time: In summer and autumn, it is appropriate to water after sunset so that the orchid leaf surface dries before nightfall; watering in the early morning is also possible. In winter and spring, watering around sunrise is better. Do not suddenly water with cold water after exposure to scorching sun, so as not to lower the soil temperature, affect root water absorption, and disturb physiological balance. The amount of water should not be too large, to help suppress disease occurrence.
Watering method: Water should be poured from the edge of the pot, and must not be poured into the flower buds, so as to avoid causing rot.
Predecessors had very good experience summaries for watering orchids. For example, in Du Men Yi Lan Ji, Yu Zhao proposed different watering methods according to the twenty-four solar terms within a year. Excerpts are given below for reference. But two points need attention: first, Du Men Yi Lan Ji uses Beijing's climate as the standard; second, the months in the text refer to the lunar calendar, not the Gregorian calendar. For example, "the first month" is actually February in the Gregorian calendar.
1. Beginning of Spring and Rain Water: Spring orchids have already set flowers, and the soil should not be too dry. Slightly moisten along the edge of the pot; if the autumn orchid pot has not dried to the bottom, do not water.
2. Awakening of Insects: When the spring orchid pot is dry to half the pot (empty above, solid below), it can be moistened with water, but not too much. Autumn orchids are the same as above.
3. Spring Equinox: Spring orchids have finished flowering and should avoid moisture. When the pot is half dry, it can be moistened with water.
4. Clear and Bright and Grain Rain: Do not let the pot soil become too dry. Moisten with water every 5 days.
5. Beginning of Summer: Orchids begin to be moved out of the room, and it is appropriate to water thoroughly once.
6. Grain Full: The pot soil should not be too dry or too wet. If spots appear on the leaves, it means it is too wet; if the tips of new shoots wither, it means it is too dry. Water 1 sheng (about a dry teacup) every 4 days, so that the lower two-thirds of the pot soil from bottom to top is moist.
7. Grain in Ear: The climate is dry, so even more attention should be paid to avoiding excessive dryness or moisture.
8. Summer Solstice: The pot soil must not be too dry. If heavy rain occurs, it can only endure one day. If there are successive cloudy and rainy days, the pot needs to be moved to a ventilated place.
9. Minor Heat: At this time the air is too humid, and the pot soil must not be too wet. The pot should be placed in a ventilated place. If it is hot and dry with little rain, water 1 sheng every 2 days. After heavy rain or one heavy wetting, one must wait until the pot soil dries to two-thirds; otherwise it should not be watered again.
10. Major Heat: The pot soil easily dries all the way through, so attention should be paid that only one heavy rain or heavy wetting per day is appropriate.
11. Beginning of Autumn: Orchids need moisture at this time. Water 2 sheng every 3 days, and it is appropriate to shield them from wind.
12. End of Heat: Water once every 5 days. Except for successive misty rain, they can be allowed to receive rain and dew.
13. White Dew: Autumn orchids need frequent watering even more than spring orchids, but after becoming wet they must dry greatly before they can be wet again.
14. Autumn Equinox: If autumn orchids have already produced flowers, watering should be slightly less; if they have not produced flowers, watering should be slightly increased.
15. Cold Dew: Autumn orchids should be watered thoroughly; spring orchids should not be watered thoroughly but should be moistened.
16. Frost's Descent: Orchids should be moved indoors, and the watering time should be changed to midday. After watering, they need to be placed in the midday sun for 1-2 hours.
17. Beginning of Winter: Only moistening with water is appropriate, about half a sheng every 5 days.
18. Minor Snow: The flower room should avoid warmth and should not be too humid. If too humid, it can cause root rot, leaf spots, and even withering. If the pot has not dried to the bottom, only slightly moisten the soil surface.
19. Major Snow: Autumn orchids do not need water; spring orchids should be slightly moistened.
20. Winter Solstice: Neither should be irrigated.
21. Minor Cold: Watering is taboo for both.
22. Major Cold: Autumn orchids still do not need water; spring orchids can be slightly moistened with water.
V. Fertilization
Orchid fertilization should be determined according to the orchid's growth condition. Those growing luxuriantly and without disease can be fertilized; those growing poorly should not be fertilized or should be fertilized only a little. For orchids newly dug from the mountains, before new roots develop, fertilization must be strictly avoided. They need 1-2 years of cultivation, and only when the new roots are vigorous can they be fertilized; otherwise they are prone to withering and dying.
Generally speaking, in June-July, when orchid leaf buds extend to about 1.5 cm, 1-2 applications of dilute decomposed liquid fertilizer can be applied (chemical fertilizer should not be used), but fertilization should not be applied in high-temperature seasons. In August-September, apply 1-2 more applications of decomposed dilute liquid fertilizer. For plain-hearted orchid varieties, 1-2 applications of plant ash extract can be used, with very good results. Fertilization is best carried out in the evening, and the next morning water once with clear water.
A relatively simple way to distinguish whether orchids need fertilization is to look at the depth of leaf color. If the leaves appear yellow and thin, it is a lack of fertilizer and topdressing should be applied; if the leaves appear black and the leaf tips are scorched, it is excessive fertilization and fertilization should be stopped.
For fertilizer, the various methods introduced above can be used to make homemade fertilizer. When applying these fertilizers, they need to be diluted with 8-9 times water, and must not be too concentrated. When fertilizing, apply it to the root zone of the plant, and never apply it to the leaf surface. The main fertilization times and dates for orchids: Number of times, date, category, first time, second time, third time, fourth time, remarks
Spring orchid category: late June, mid-July, mid-August, early September. The fourth time should be especially dilute.
Summer orchid category: late June, mid-July, mid-August, early September. The fourth time should be especially dilute.
Autumn orchid category: early June, late June, late July, mid-August. The fourth time should be especially dilute.
VI. Pruning
During orchid cultivation, pruning must be carried out continuously. When old leaves turn yellow and withered, they should be cut off in time to facilitate ventilation. If the leaf tips of some leaves dry up, they should also be cut off. In particular, leaves harmed by pests and diseases need to be removed in time to avoid contagion. When cutting off leaves with viral disease, the scissors used should not then be used to cut disease-free leaves, in order to prevent virus transmission. If the same pair of scissors is used, it must be disinfected. For precious orchids, after flower buds emerge from the soil, if there are too many flower buds, strong buds should be kept and the remaining thin and small flower buds removed. It is appropriate to keep 1-2 flower buds per pot. If there are too many flower buds, it will not only make the current year's flowers bloom poorly, but also consume too many nutrients from the mother plant and affect the next year's flowering. Generally, orchids do not need flower buds cut off. Spring orchid flowers bloom for about half a month, and then the flowers need to be cut off; for summer orchid flowers, when the last flower on the inflorescence has been open for one week, the inflorescence should also be cut off. Precious varieties should not be allowed to pollinate and set seed, otherwise it will affect the next year's flowering. If used for hybrid breeding, then they need extra careful cultivation to make the fruit plump and mature.
VII. Cold Protection
Autumn orchids should have cold protection work done earlier. For example, when the temperature is 2-3°C, they can be moved indoors. Cold orchids grow in the south and need even earlier cold protection. Spring and summer orchids have relatively strong cold resistance, but if freezing occurs, they must also be moved indoors in time. A room temperature of 1-2°C is enough for overwintering. If a severe cold current strikes and the room temperature drops below zero, heating should be carried out in time; generally it is enough to keep the room from freezing. Indoors, autumn orchids should be placed on the south-facing side, and spring and summer orchids on the other side. Around noon, windows should be opened on the south and southeast sides for ventilation (autumn orchids should not have windows opened on cloudy days at 1-2°C, to prevent cold wind from blowing in and freezing the leaves). Autumn orchids prefer to be a bit dry in winter; the pot soil of the other orchids should be kept moist.
VIII. Flower Removal
For orchids growing poorly, with few leaves per clump, or with poor roots, flower removal should be carried out. For relatively good varieties, spring orchids can appropriately have 1-2 flower buds removed; for summer orchids, when the flower buds extend, keep 1-2 flower buds and remove the rest. In this way, the flowers can bloom longer, more new leaves can be sent out, and old leaves are less likely to wither and die. Precious spring orchid flowers should be removed after blooming for 3-5 days, so that leaf buds grow robustly; when the summer orchid flower has opened to the topmost one, it can also be cut off at a distance of cm from the pot surface.
IX. Flood Prevention
If the cultivation site is open on all sides and the terrain is relatively high, wind prevention work needs to be done well in summer when strong winds or typhoons pass through, so as to prevent the leaves of summer orchids or cold orchids from being broken and damaged.
X. Mist Spraying
In dry seasons, spray mist on the balcony where potted flowers are placed every evening, mainly to make the ground moist and increase air humidity. The pot surface of orchids should also be sprayed with mist. When spraying, spray upward so that the mist droplets fall finely and evenly and the leaf surface is moist. This can promote good orchid growth and make the leaf surface glossy.
XII. Pest and Disease Control
Sterilization treatment should be carried out (exposure under the scorching sun is sufficient) to prevent disease occurrence. Orchids are most prone to southern blight in rainy and high-temperature seasons, and thiophanate or Bordeaux mixture at 800 times dilution can be sprayed for prevention. If the disease is severe, thiophanate at 500-750 times dilution can be used, sprayed once every 7-10 days. Among insect pests, scale insects occur most frequently. This insect attaches to the base of the leaves. If scale insects are found, they should be removed in time. To avoid scale insect invasion, starting in April, "1059" at 2000 times dilution can be used for control. In order to suppress the occurrence of orchid diseases, in addition to appropriately controlling the dryness and moisture of the pot soil at ordinary times, clay pots should also be used as much as possible and glazed pots used less when selecting flowerpots. Especially for poorly growing orchids newly dug from the mountains, clay pots must be used for planting. Doing so makes the pot soil dry easily, which can promote orchid growth and reduce disease occurrence.
How should orchids be grown well?
1. Potting soil requirements: A neutral to slightly acidic soil rich in humus, loose, and well-draining is best, with a pH generally around 5.5 to 6.5. In Sichuan, Emei Xiantu and "Xinghong brand" refined orchid potting medium are often used, but more commonly "bamboo root mud" and leaf mold from broadleaf forests in mountainous areas are used to cultivate orchids.
2. Placement location: Orchids can be grown outdoors and on balconies in spring, summer, and autumn. Choose a spot with good ventilation, moist air, and no environmental pollution. A location near ponds or riversides is naturally good, but at minimum there should be tall trees or bamboo groves and shade netting to reduce sunlight exposure and lower the temperature. Orchid pots are best placed on wooden racks (or steel racks). If placed on the ground, bricks should be used as a base. For home balconies, a small galvanized iron water trough can be used to store water, with bricks placed on top for growing orchids, increasing humidity.
3. Appropriate shading: Most orchids are semi-shade plants, and most species are afraid of direct sunlight, so appropriate shading is needed. In early to mid-April, the netting can be removed and windows opened to let in more sunlight to promote growth. In May, except for the midday sun, they can receive 6 hours of sunlight. Starting from June, shade all day long. After October, except for midday, they can be fully exposed for care. Remember the saying: "More shade makes good leaves, more sun makes good flowers."
4. Reasonable fertilization: Orchids are naturally "vegetarian," and fertilization should depend on the chosen potting soil and growth conditions. Those growing vigorously without disease can be fertilized; those growing poorly should not be fertilized or only given a small amount. Newly potted orchids whose roots have not fully developed should not be fertilized until after 1-2 years. Generally, in June-July when orchid leaf buds extend to about 1.5 cm, apply decomposed liquid fertilizer once every three weeks (dilute concentration of about 10% is suitable). Avoid chemical fertilizers. During high-temperature seasons, fertilization is not suitable. In August-September, apply diluted liquid fertilizer once every two to three weeks. Each fertilization of orchids should be done in the evening, and clear water should be watered the next morning, called "return water."
5. Appropriate watering: Rainwater and spring water are best for watering orchids. Tap water or rice-washing water should be left overnight before use. When watering, pour from the edge of the pot, and do not pour into the flower buds. The amount of water should be determined by temperature, the dryness of the potting soil, and the growth condition of the orchids. Those with large leaves should be watered more; those with slender leaves, less. In April-May, when new shoots have not yet emerged from the soil, the potting soil should be kept somewhat dry; if too wet, new shoots easily rot. June-September is the growing period for new orchid shoots, and water quantity should be increased. On sunny days, water once each morning or [once daily]. Never water under the blazing midday sun. In autumn, reduce water as appropriate; misting the leaves can be used to keep the potting soil moist. In winter, water should be controlled even more, maintaining "80% dry, 20% moist" as suitable.
6. Evening misting: Orchids originally grow in humid environments, so in dry seasons, besides shading, evening misting is also necessary to increase air humidity and lower temperature. Water can also be poured on the ground (or platform) where orchids are placed. The "cold and hot" contrast can further stimulate orchid growth.
7. Wind and rain protection: "February ghost wind" causing old leaves to yellow and drop is normal; dead branches and withered leaves can be cut off. Orchids can tolerate light rain, but should avoid moldy rain, heavy rain, or continuous rain, otherwise the heart and leaves easily rot. In rainy seasons, a small amount of plant ash can be scattered appropriately.
8. Pruning and flower removal: During orchid cultivation, withered yellow, broken, and diseased leaves should be regularly cut off to facilitate ventilation. For precious orchid varieties, if there are too many flower buds, keep only the strong ones, with 1-2 flower buds per pot being suitable. Spring orchids (Cymbidium goeringii) should have flowers removed half a month after blooming, and precious orchid varieties after 7 days. When spring orchid leaf buds grow vigorously, flowering will be better the next year. For summer orchids (Cymbidium ensifolium), when the last flower on the inflorescence has been open for one week, cut it off 3 cm from the pot surface.
9. Cold protection and warmth: Because orchid varieties differ, their places of origin vary, and their cold resistance also differs, the time to move them indoors in winter and their indoor placement also differ. Cold orchids (Cymbidium kanran), autumn orchids, and New Year orchids (Cymbidium sinense) grow in the south and should be moved indoors (or have windows closed and netting drawn) when the temperature is 5°C, and placed as much as possible in a south-facing sunny spot. Spring and summer orchids have strong cold resistance and can stay out until 0°C before being moved indoors, placed on the northeast side. On sunny, windless days around noon, windows facing south or southeast should be opened and netting pulled for ventilation. Autumn orchids should not have windows opened on sunny days at 1-2°C. Of course, if a greenhouse is available, electric heating can be used.
10. Disease and pest control: Potting soil should generally be sterilized (sun exposure also works) to prevent disease. Orchids are most prone to southern blight (Sclerotium rolfsii) in rainy, high-temperature seasons. For a small amount, wipe off with a damp cloth. For many pots, use 500-800 times Bordeaux mixture or thiophanate-methyl, spraying once every 7-10 days. The most common pest is scale insects (commonly called "orchid lice"). During the hatching period, use 1% omethoate and 25% phosmet emulsifiable concentrate at 1000 times dilution, spraying once a week. Treating symptoms must also address the root cause: pots should be spaced appropriately, placed at varying heights, increasing air circulation, to reduce disease occurrence.
(2) Ecological habits of orchid cultivation
Orchids are native to China. They prefer warmth and humidity, with warm winters and cool summers being most ideal, and they absolutely avoid high temperatures and dryness. In winter, it is best if it does not freeze, with 3°C-7°C being most suitable, and in summer 25°C-28°C is appropriate. In their natural distribution, orchid habitats are near streams and ravines, receiving rain and dew year-round, with annual rainfall required to be above 1000 mm. They require deep topsoil rich in humus, dark brown, loose and fertile, with good water permeability and retention, in slightly acidic soil, pH 5 to pH 6.5, and they dislike waterlogging.
Orchids prefer shade and require short sunlight duration. In their natural distribution, spring orchids require tree canopy density of 0.7-0.95; Cymbidium faberi requires 0.5-0.8, with slightly longer light duration than spring orchids; Cymbidium ensifolium, Cymbidium sinense, and Cymbidium kanran also require high canopy density for shade. Cymbidium plants have a dormancy habit in their native areas, depending on rainy and dry seasons. Usually the dry season is in winter, which is the dormancy period for orchids, and the rainy season is in spring and summer, which is the growing period, when they can continuously bud and bloom.
(3) Propagation methods for orchid cultivation Orchids are commonly propagated by division, sowing, and tissue culture.
1. Division: Can be done in both spring and autumn, generally once every three years. Any plant with robust growth and densely clustered pseudobulbs can be divided. After division, each cluster should retain at least 5 connected pseudobulbs. Before division, reduce watering to make the potting soil somewhat dry. When potting after division, first cover the drainage hole with broken tile pieces, then spread coarse gravel, occupying 1/5 to 1/4 of the pot depth, then add coarse-grained soil and a small amount of fine soil, and finally plant with sandy loam rich in humus. The planting depth should just barely bury the pseudobulbs in the soil, leaving a 2 cm rim at the pot edge, topped with Selaginella uncinata or fine gravel, and finally water thoroughly. Place in a shaded area for 10-15 days, keep the soil moist, gradually reduce watering, and carry out normal care.
2. Seed propagation: Orchid seeds are extremely fine, containing only one incompletely developed embryo, with very low germination capacity. Additionally, the seed coat does not easily absorb water, so conventional sowing methods cannot achieve germination. Orchid mycorrhiza or artificial culture media are needed to supply nutrients for germination. For sowing, it is best to select fruits that have not yet split open. After surface sterilization with 75% alcohol, remove the seeds, soak in 10% sodium hypochlorite for 5-10 minutes, remove and rinse 3 times with sterile water, then sow in culture bottles containing medium. Then place in a dark culture room, maintaining temperature at about 25°C. After germination, move to light to form protocorms. From sowing to transplanting takes half a year to a year. Tissue culture has been successfully achieved, and where conditions permit, this method can be used for propagation.
(4) Orchid cultivation techniques
1. Site selection: Requires open surroundings, good ventilation, near water, with humid air and no coal smoke pollution. On the southwest side of the site, evergreen broadleaf trees can be planted, with canopy density of about 0.7, which can reduce afternoon sunlight exposure and regulate humidity and temperature.
2. Watering: Rainwater or spring water is preferred. Avoid water containing salt and alkali. If using tap water, let it sit for several days before use. Watering should depend on temperature conditions. In spring, water less; in summer, more. The plum rain season coincides with orchids sending out leaf buds, so the potting soil should be somewhat dry. After autumn when the weather turns cool, reduce watering, keeping it moist is sufficient. In winter indoors, keep dry and reduce watering frequency, and water at noon. Orchids can tolerate light rain, but continuous rain or heavy rain easily causes heart and leaf rot, so attention must be paid to rain protection.
3. Fertilization: For orchid cultivation, cake fertilizer is suitable. Mix 4 parts plant ash, 10 parts soybean cake, and 10 parts bone meal evenly, place in a vat, add water in several batches until the soybean cake is soaked through, then cover and seal. After one year of decomposition, make into dry granules. Place on the pot surface when using. If using full manure, it should also be decomposed for one year, diluted with water, filtered, and used. Generally, start fertilizing from May and stop at the Beginning of Autumn (around August 7-8), applying thin fertilizer frequently. Fertilization should be done in the evening, and clear water should be watered once the next morning.
4. Shading and cold protection: Except for early spring and winter, they should be placed under open-air sheds. The shade shed requires good ventilation. When orchids first come out in March-April, they can get more sunlight, and afterward the shading time gradually increases. In winter, orchids must be moved indoors for cold protection, with room temperature maintained at 1°C-2°C. Additionally, after orchids come out in spring and before they go indoors in autumn, attention should also be paid to frost protection.
5. Disease and pest control: The main diseases and pests of orchids are:
(1) Southern blight: Mostly occurs in the plum rain season. Attention should be paid to ventilation and light penetration, and good pot soil drainage for prevention. After onset, remove the infected potting soil and sprinkle with quintozene powder or lime.
(2) Anthracnose: Present year-round, more rampant in high-temperature, rainy seasons. Control methods include improving environmental conditions; during onset, first spray with 50% thiophanate-methyl wettable powder at 800-1500 times dilution, once every 7-10 days, then supplement with 1% equal-amount Bordeaux mixture, once every half month.
(3) Scale insects: Under high temperature, high humidity, and poor air circulation, they reproduce fastest. Use conventional control methods.
In summary, to grow orchids well, one must understand their natural growing environment conditions, take reasonable measures, and strengthen care and management. According to "Orchid Cultivation Secrets": "In spring do not bring out, in summer do not expose to sun, in autumn do not dry out, in winter do not keep wet." This is a summary of China's orchid cultivation experience.
A brief discussion on rational use of pesticides for orchids
Fungicides are agents for preventing and treating crop diseases. In our daily prevention and treatment of orchid diseases, we should select according to the different properties and modes of action of different categories of fungicides. One type is protective fungicides, whose function is to treat plants or the plant's environment before pathogen invasion. They need to be used before plants come into contact with pathogens or before disease occurs to be effective, such as Bordeaux mixture, lime sulfur mixture, mancozeb, zineb, etc. Another type is therapeutic fungicides, which we often encounter. Their characteristic is systemic action. These fungicides are used when pathogens have already invaded the plant body or the plant is already diseased, to reduce or eliminate plant disease. Applying medication in the early stage of disease onset will give better results.
The onset and peak periods of different pathogens also differ, greatly influenced by external environment, especially the growth and development status of infected crops and temperature and humidity. (Therefore, we must grow orchid seedlings strong.) When preventing and treating diseases, it would be better to be familiar with the living habits and epidemic patterns of pathogenic bacteria. Disease prevention can be carried out according to different seasons and temperature environments, which plays a huge role in the effective exertion of pesticide efficacy. Crop diseases caused by various pathogens are different, and symptoms are also noticeably different. Therefore, when selecting fungicides, targeted medication is required. Moreover, the efficacy should be significant and lasting. One should not blindly pursue high efficiency, broad spectrum, or even "universal" agents, treating all diseases with just one pesticide. This is certainly not acceptable. When using pesticides, attention should be paid to preventing the development of pathogen resistance, meaning the same fungicide should not be used continuously, nor should the same type of fungicide be used several times consecutively in one growing season. Systemic agents especially should have their usage frequency limited. For example, in production, systemic agents can be combined or alternated with chlorothalonil, mancozeb, etc.
In our daily pesticide use, we should follow the patterns of pathogen infection and take corresponding control measures. When using fungicides to directly spray orchid plants, attention should be paid to the influence of natural conditions to prevent loss of efficacy or pesticide damage. When temperature and humidity are high, the concentration of the pesticide used can be appropriately reduced. For pesticides that easily decompose or volatilize under strong light, application should be done on cloudy days or in the evening. Different pesticides all have certain ranges of use. Only by deeply understanding them and mastering their usage characteristics can pesticides be correctly selected to achieve twice the result with half the effort. Carbendazim is a systemic fungicide commonly used by everyone, capable of controlling dozens of fungal diseases. Ascomycetes and deuteromycetes are especially sensitive to it, but it is ineffective against diseases caused by bacteria and oomycetes among fungi. Therefore, when plant infection with fungal disease is confirmed and repeated use of carbendazim is ineffective, consideration should be given to switching to phenylamide pesticides (such as metalaxyl). These are mainly used for downy mildew, phytophthora, and pythium diseases caused by oomycetes, but have poor effects on diseases caused by other fungi and bacteria. Chlorothalonil is a non-systemic broad-spectrum fungicide with preventive effects against many plant fungal diseases. It can prevent pathogen spore germination, hinder mycelial development and spore formation, and can control diseases resistant to carbendazim, but has poor control effects on soil-borne pythium diseases. Therefore, frequently switch fungicides. (Huakang is claimed to kill all diseases; whether true or not, I dare not be careless when using it, and still mix it with other fungicides.) Strive for maximum protection of orchid plants, so they are not tormented by disease. When orchids grow healthy, orchid enthusiasts are also happy.Figure 1 Ring spot disease + anthracnose (Colletotrichum)
Ring spot disease + anthracnose (Colletotrichum) routine preventive medication:
Pesticide name: 77% Kocide wettable powder; Mode of action: Broad-spectrum protective fungicide; Usage: 1000 times dilution / 3-4 applications / 7-day interval, spray / leaf underside, leaf surface; Also prevents: brown spot disease, anthracnose, leaf spot disease, ring spot disease, bacterial brown spot disease;
Pesticide name: 25% Sportak emulsifiable concentrate; Mode of action: Broad-spectrum fungicide; Usage: 1500 times / 2-3 applications / 8-day interval, spray / leaf underside, leaf surface; Also prevents: anthracnose, leaf spot disease, sooty mold, black spot disease, round spot disease, ring spot disease;
Pesticide name: 80% mancozeb wettable powder; Mode of action: Broad-spectrum protective fungicide; Usage: 800 times / 3-4 applications / 6-day interval, spray / leaf underside, leaf surface; Also prevents: anthracnose, leaf spot disease, sooty mold, black spot disease, round spot disease, ring spot disease;
Ring spot disease + anthracnose (Colletotrichum) supplementary notes:
1. Because most control prescriptions for anthracnose are emulsifiable concentrates or mancozeb-type, attention must be paid to weather temperature and UV index when using them.
2. When temperature exceeds 30°C, try to avoid emulsifiable concentrates and copper-based pesticides. When UV is too high, try to apply pesticides before 5 AM or after 6 PM.
3. It is recommended to mix two prescription fungicides together during normal application, as this provides multi-faceted treatment and defense.Figure 2 Ring spot disease + leaf spot disease
Ring spot disease + leaf spot disease routine preventive medication
Pesticide name: 80% mancozeb wettable powder; Mode of action: Broad-spectrum protective fungicide; Usage: 800 times / 3-4 applications / 6-day interval, spray / leaf underside, leaf surface; Also prevents: anthracnose, leaf spot disease, sooty mold, black spot disease, round spot disease, ring spot disease;
Pesticide name: 77% Kocide wettable powder; Mode of action: Broad-spectrum protective fungicide; Usage: 1000 times dilution / 3-4 applications / 7-day interval, spray / leaf underside, leaf surface; Also prevents: brown spot disease, anthracnose, leaf spot disease, ring spot disease, bacterial
Ring spot disease + leaf spot disease supplementary notes: Before the leaves of diseased orchids wither, if one does not look carefully, ring spot disease is often mistaken for general leaf spot disease or [...] The treatment [...]
2. It is recommended to mix two prescription fungicides together during normal application, as this provides multi-faceted treatment and defense.Figure 3 Mild nutrient deficiency disease (zinc, magnesium, iron)
Mild nutrient deficiency disease (zinc, magnesium, iron) routine preventive medication: Although this is a diseased state, it is not contagious. Regularly supplement with some trace elements and fertilizers containing zinc, magnesium, iron, and calcium during fertilization. Mild nutrient deficiency disease (zinc, magnesium, iron) supplementary notes: Regularly supplement with some trace elements and fertilizers containing zinc, magnesium, iron, and calcium during fertilization.Figure 4 Soft rot + black spot disease
Pesticide name: 72% agricultural streptomycin sulfate wettable powder; Mode of action: Antibiotic fungicide; Usage: 800 times / 2-3 applications / 7-day interval, spray, root drench; Also prevents: bacterial brown spot disease, soft rot;
Soft rot + black spot disease supplementary notes: Since this is a condition where both fungi and bacteria occur simultaneously, two different fungicides must be mixed for use. Because the mixing of two fungicides each has its own concentration dilution, this often brings confusion to beginner orchid enthusiasts. Here is a supplementary explanation: Ratio: For 100 jin of water, use the bacterial one, streptomycin sulfate at 500 times, mixed with the fungal one, carbendazim at 1000 times.
1. For 100 jin of water at streptomycin sulfate 500 times, streptomycin sulfate needs 100 grams.
2. For 100 jin of water at carbendazim 1000 times, carbendazim needs 50 grams.
3. That is, using 100 grams of streptomycin sulfate equals (500 times) + 50 grams of carbendazim equals (1000 times), both placed into 100 jin of water and mixed for use. Only this counts as the correct pesticide dosage preparation.Figure 5 Leaf tip anthracnose + leaf blight
Leaf tip anthracnose + leaf blight routine preventive medication
Pesticide name: 25% propiconazole emulsifiable concentrate; Mode of action: Broad-spectrum systemic fungicide; Usage: 1500 times / 2-3 applications / 8-day interval, spray / leaf underside, leaf surface; Also prevents: brown spot disease, round spot disease, anthracnose, leaf spot disease, leaf tip blight;
Pesticide name: 10% Score water-dispersible granules; Mode of action: Broad-spectrum systemic fungicide; Usage: 3000 times / 2-3 applications / 8-day interval, spray / leaf underside, leaf surface; Also prevents: brown spot disease, leaf spot disease, black spot disease, round spot disease, leaf blight, ring spot disease, leaf tip blight, sooty mold;
Leaf tip anthracnose + leaf blight supplementary notes: Because it is a cross-symbiosis of two pathogens, it is recommended to use two fungicides for relatively simple control. Regarding the mixing method of two fungicides, here is a repeat: When two conditions occur simultaneously, two different fungicides must be mixed for use. Because the mixing of two fungicides each has its own concentration dilution, this often brings confusion to beginner orchid enthusiasts. Here is a new supplementary explanation: Ratio: For 100 jin of water, use the bacterial streptomycin sulfate at 500 times mixed with the fungal carbendazim at 1000 times.
1. For 100 jin of water at streptomycin sulfate 500 times, streptomycin sulfate needs 100 grams.
2. For 100 jin of water at carbendazim 1000 times, carbendazim needs 50 grams.
3. That is, using 100 grams of streptomycin sulfate equals (500 times) + 50 grams of carbendazim equals (1000 times), both placed into 100 jin of water and mixed for use. Only this counts as the correct pesticide dosage preparation.Figure 6 Leaf margin black spot disease
Leaf margin black spot disease routine preventive medication
Pesticide name: 80% mancozeb wettable powder; Mode of action: Broad-spectrum protective fungicide; Usage: 800 times / 3-4 applications / 6-day interval, spray / leaf underside, leaf surface; Also prevents: anthracnose, leaf spot disease, sooty mold, black spot disease, round spot disease, ring spot disease.
Pesticide name: 10% Score water-dispersible granules; Mode of action: Broad-spectrum systemic fungicide; Usage: 3000 times / 2-3 applications / 8-day interval, spray / leaf underside, leaf surface; Also prevents: brown spot disease, leaf spot disease, black spot disease, round spot disease, leaf blight, ring spot disease, leaf tip blight, sooty mold;
Pesticide name: 25% Sportak emulsifiable concentrate; Mode of action: Broad-spectrum fungicide; Usage: 1500 times / 2-3 applications / 8-day interval, spray / leaf underside, leaf surface; Also prevents: anthracnose, leaf spot disease, sooty mold, black spot disease, round spot disease, ring spot disease;
Pesticide name: 50% Sportak wettable powder; Mode of action: Broad-spectrum fungicide; Usage: 2000 times / 2-3 applications / 8-day interval, spray / leaf underside, leaf surface; Also prevents: anthracnose, leaf spot disease, sooty mold, black spot disease, round spot disease, ring spot disease;
Leaf margin black spot disease supplementary notes: Actually, many orchid leaf diseases use fungicides of similar nature, but as our professional introduction, we must mention all disease conditions for orchid enthusiasts to understand. In general, choosing broad-spectrum and systemic pesticides is best.
Experience reminder: In my experience, the key work when purchasing pesticides is choosing manufacturer reputation and clearly labeled ingredients, to avoid the situation of having the psychological comfort of sterilization but ending up with fake pesticide ingredients, resulting in the disease not being controlled and missing the golden time for treatment.
Experience reminder: The second cause of harm is: thinking these pesticides may have insufficient labeled ingredients and instead increasing the concentration or dilution. Who knew that this time genuine pesticide was bought, and as a result, increasing the dilution caused severe pesticide damage. Haha! One can only silently ask heaven.Figure 7 Phytophthora disease
Phytophthora disease routine preventive medication
Pesticide name: 72% Curzate wettable powder; Mode of action: Systemic fungicide; Usage: 1500 times dilution / 2-3 applications / 10-day interval, drench root and stem; Also prevents: Phytophthora disease
Pesticide name: 50% Anke wettable powder; Mode of action: Systemic fungicide; Usage: 12500 times / 2-3 applications / 10-day interval, drench root and stem; Also prevents: Phytophthora disease
Phytophthora disease treatment supplementary notes:
1. During the peak onset period, continuous preventive medication must be used. Having understood the characteristics of stem rot, we can only use targeted fungicides.
2. 72% agricultural streptomycin sulfate soluble powder at 800 times dilution, 77% Kocide powder at 1000 times dilution, spray leaf underside, leaf surface, and crown
3. Mifenan (emulsifiable concentrate) 1500 times + tetracycline (powder) 2000 + dimethomorph (powder) 2000 times dilution, spray leaf underside, leaf surface, and crown
4. Antaison 500 times + Mifenan 1500 times + streptomycin sulfate 500 times dilution, spray leaf underside, leaf surface, and crown. (When applying fertilizer or pesticide, you must spray the leaf underside, because plants absorb through the stomata on the leaf underside.)
5. Every 20 days or so, use Dexon 800 times + tetracycline 3000 times dilution for thorough root drenching.
6. Fungicides must be alternated and rotated to avoid developing resistance and delaying treatment.Basic principles of orchid cultivation and management techniques - Orchid cultivation techniques
1. Preparation of growing medium: Planting orchids requires specially prepared growing medium, also called orchid mud. Orchid growing medium should be loose, breathable, well-draining, with appropriate fertilizer, and free of hidden pests and diseases. The composition of growing medium is made from one or several basic components (substrates). These basic components include soil, fertilizer, and other materials, with quite many types. Some components seem unrelated to soil, but they are all substrates on which orchids rely for stabilizing the plant and for growth and development.
(1) Growing medium formulas.
In the East China region, orchid growers generally prefer orchid mud from Shaoxing, Yuyao, and other places. In recent years, Emei Hewang brand Xiantu has also been welcomed by people, but these growing media are limited in quantity and expensive, only suitable for repotting. Large-scale ground planting requires hundreds or thousands of tons of growing medium, so only local materials can be used. After years of practice and repeated screening, we determined the best formula: 4 parts yellow sandy soil, 4 parts sawdust, 2 parts river sand; if using yellow loam, then 1 part river sand, 1 part sawdust, 1 part yellow loam. All thoroughly mixed. The prepared growing medium should have a pH between 6.5-6.8, be loose and breathable, with excellent water retention and drainage, and comprehensive nutrition. River sand and sawdust serve for water conduction and aeration. Sawdust is decomposed by bacteria, slowly releasing nitrogen, phosphorus, potassium, etc. Yellow loam also contains various trace elements. After years of observation, this formula is very suitable for orchid growth. It is especially suitable as a substrate for domesticating and cultivating wild orchids. It is suitable for spring orchids (Cymbidium goeringii) and Cymbidium faberi, and also ideal for Cymbidium ensifolium and Cymbidium kanran. Both flowering rate and stress resistance are significantly increased.
(2) Bamboo root mud.
This refers to the soil at the roots of bamboo clumps that have been planted for many years. Due to the spreading of bamboo rhizomes and bamboo roots, as well as the decomposition of bamboo leaves and shoot sheaths, this soil becomes loose in structure, well-draining, with a certain fertility but not overly fertile, suitable for orchid growth. The quality of bamboo root mud depends on three factors: First, the original soil quality, which is the predecessor and foundation of bamboo root mud, with sandy loam being best; second, the age of the bamboo clump planting, the longer the time, the more fully the bamboo roots, bamboo leaves, and bamboo rhizomes have acted; third, the distance from the bamboo stump, the closer to the bamboo stump, the better the soil.
(3) Vetch chaff soil.
Vetch chaff is made by harvesting, sun-drying, and crushing green manure (Chinese milk vetch) plants. Mix vetch chaff with bamboo root mud or general sandy loam, pile up, and decompose to make vetch chaff soil. The preparation method: Choose a rain-sheltered site, spread a layer of soil, scatter a layer of vetch chaff, pour a round of *manure water, and pile up layer by layer. After piling, sprinkle water on the surface to moisten, then cover with thin mud to seal. After piling and fermenting for half a year, it is ready for use.
When using, mix in proportion with other growing media.
(4) Leaf mold.
Made by piling fallen leaves or green grass and tall stalks, watering or applying fertilizer, covering with thin mud to seal, and after decomposition and screening. It is best to use green grass that has not set seed, and after full decomposition, kill pests, diseases, and weed seeds, otherwise there will be many weeds in the orchid pots later.
(5) Mountain soil.
This is the forest soil where wild orchids originally grow. It is formed by years of accumulation and decomposition of dead branches and fallen leaves mixed with soil. Naturally formed leaf mold contains rich humus, is loose and breathable, and is very suitable for orchid growth. When transportation is convenient, digging large amounts of mountain soil for planting orchids is relatively simple and economical, and even better for domesticating raw orchids. Humus soil under broadleaf forests, especially leaf mold under chestnut trees, is an extremely ideal soil for orchids.
(6) Pond mud.
During winter maintenance of ponds and fish ponds, the mud is dug out, sun-dried, then broken into fine particles. It can be used to cultivate all flowers, including orchids.
(7) Field soil.
Select loose topsoil from fields, mix in a small amount of sandy soil or a small amount of rice husk ash, then add some decomposed compost or fermented decomposed soybean cake, rapeseed cake, and other organic fertilizers, to promote soil structure improvement and enhance fertilizer efficacy. After multiple turnings and mixings, then screen. This soil is nearly neutral, not as good as humus soil. So it is only used reluctantly when there is no suitable humus soil or mountain sandy loam, mostly for cultivating coarse orchid varieties.
(8) Cow dung soil.
Crush and grind fermented dry cow dung, mix into sandy soil or field topsoil at a 1:3 ratio. It is best to select cow dung from cattle fed dry feed in winter, because after dry forage is ruminated through the cow's stomach, although the fibers are finely broken, they still retain elasticity and are plant fibers containing certain nutrients. This cow dung soil is soft and rich in fertilizer, extremely suitable for the air-loving orchid roots. In Taiwan, China's orchid cultivation circles, this cow dung soil is often used as filler material for cultivating terrestrial orchids, with good results. In foreign countries, for cultivating terrestrial orchids, generally 5 parts humus soil or leaf mold plus 1 part sand is used; or 3 parts peat soil plus 1 part river sand, mixed with crushed dry cow dung, thoroughly mixed before use. For epiphytic orchids, the cultivation substrate is mainly moss and ferns, with a small amount of leaves, small pieces of charcoal, and crushed dry cow dung added. Before using soil to plant orchids, expose the soil to sunlight for disinfection and sterilization. In summer, spread out the soil and let it sun-expose for more than 3 days, which can kill pathogens and insect eggs. Before use, the growing medium should have its pH tested and adjusted. For overly acidic soil, lime can be used to adjust. For overly alkaline soil, calcium superphosphate, ferrous sulfate, etc. can be mixed into the soil. In summary, controlling soil pH to be neutral to slightly acidic is best (i.e., pH 5.5-7). Using organic fertilizers, such as green grass and leaves composted into fertilizer, added to soil to change soil pH is a better method. Additionally, before planting orchids, the nutrient soil should be screened and graded, separating large particles from small particles.
When planting orchids, place large particles at the bottom of the pot to facilitate drainage. At the same time, the soil moisture level should also be adjusted properly, not too wet and not too dry. Best is to take soil in the hand and squeeze hard, the soil can form a clump; release the hand and shake it, the soil disperses into particles again. Such moisture level is suitable.
2. Preparation of orchid growing site 1. Production-scale ground planting: The original environment for terrestrial orchids is growing in mountain forests and secluded valleys, with high, refreshing terrain, tree shade, forming a humid microclimate. Small temperature differences, clean air.
When introducing and domesticating, one should first simulate their wild environment to achieve lush flowers and leaves. Currently, with industrial development and urban modernization, greening work cannot keep up accordingly for the time being, and they are affected by pollution from factories and vehicles. So orchids cultivated in cities are not as robust as those grown in suburbs. There is a gap with the original environment of wild orchids, and a great difference from the meteorological factors of the original habitats of Cymbidium kanran and Cymbidium ensifolium. Therefore, careful design was made for the domestication and orchid planting site, and practical arrangements were made for regulating environmental factors.
The orchid nursery covers about 15,000 sq m, rectangular in shape. There is a rectangular water pond in the nursery for storing rainwater. Every 2.5 m or so, a 2.5 m tall moso bamboo pole is fixed, with bamboo poles tied horizontally on top to form a frame, used to lay the first layer of shade netting. At 20 cm below the first layer of shade netting, another horizontal thin bamboo pole is placed, used to lay the second layer of movable shade netting. The first layer of shade netting is basically fixed from spring to autumn, and the second layer can be retracted or extended as needed. Carefully regulate light and temperature. The seedling bed width is 1.2 m, length 12-16 m (depending on terrain), height about 30-40 cm (5-7 bricks high), seedling bed spacing 50 cm, pathway width 130 cm. Convenient for daily management. In winter, a plastic greenhouse is erected over every two beds for warmth. On snowy days, pay attention to clearing snow to avoid excessive snow crushing the plastic greenhouse. About every mu (1 mu ≈ 667 sq m) of land, two water troughs with 1 cubic meter storage capacity are built to treat tap water. In winter, 100-150 watt light bulbs are placed about every 4 m inside the plastic greenhouse, mainly for heating.
2. Open-field cultivation
(1) Ground planting of orchids under tree shade.
This is for ornamental purposes, using sparse tree shade in front of houses, wall corners, or scenic areas for appropriate ground planting, but the original poor clay soil must be dug out and replaced with loose humus soil or good field topsoil.
When winter arrives, spread some straw on the soil surface around the roots to prevent frost damage to orchid roots. If there is severe cold, straw curtains or other soft covering materials should also be laid over the leaf clusters to prevent frost damage. This kind of ground-planted orchid cultivation, except for strengthening management and protection during midsummer heat, can generally be extensive, allowing natural growth. Orchids planted in open fields are all coarse varieties without petal-type classification. The following spring, after the weather warms up, the cold-protection coverings can be removed. After years of growth, as long as watered and fertilized timely, their adaptability is still relatively strong, capable of blooming abundantly every year, with delicate fragrance drifting far, making them a fine item for embellishing the countryside.
However, when arranging ground-planted orchid cultivation, besides considering the serene layout,
(2) Potted orchid cultivation.
This refers to shade-shed orchid cultivation.
For potted orchid cultivation, it is best to use clay pots, i.e., unglazed earthenware pots. They have good breathability, can filter water, and are inexpensive. They are economical and practical orchid-growing supplies. But clay pots are rather rough and not attractive, unsuitable for exhibition. Porcelain pots or glazed pots are attractive in appearance, but their breathability and drainage are very poor. If used for long-term orchid cultivation, orchid roots easily rot, making it difficult for orchids to grow vigorously. So when using porcelain or glazed pots for orchid cultivation, more drainage tile pieces must be placed at the bottom of the pot, or fillers like clam shells; and watering must be controlled, not excessive. If using clay pots to grow orchids, they can be placed inside larger porcelain or glazed pots when participating in exhibitions. Yixing purple clay pots are attractive and elegant in appearance, and have certain breathability, relatively suitable for orchid cultivation. Newly purchased orchid pots must be soaked in water for several days. Especially newly kilned clay pots must be allowed to absorb enough water to completely eliminate their fiery dryness. For general orchid cultivation, newly planted orchids mostly use new pots, and repotting mostly uses old pots. For all potted orchids, it is best not to place them directly on the ground, because they are easily disturbed by pests and weeds. Especially in hot summer, when the blazing sun is scorching and ground temperature rises, damaging orchid plants; during thunderstorms and plum rain seasons, humid heat rises even more, easily steaming orchid roots; moreover, being close to the ground, ventilation is poor. [This is] beneficial for aerial root growth. To reduce the above effects, orchid pots can be placed on orchid benches made of cement boards, facilitating vertical convection, continuously supplying fresh air, promoting orchid respiration, enhancing metabolic function, accumulating nutrients and energy production, making orchids grow robustly, and also avoiding ants, slugs, and other pests harming orchid roots. If limited by conditions, an empty clay pot can be inverted on the ground, and the orchid pot placed on top.
3. Orchid room cultivation: The orchid room is mainly for terrestrial orchids to overwinter.
Different orchid species have different ecological habits, so the time to move indoors for winter and the room temperature requirements also differ. For terrestrial orchids, as long as the temperature is not below 7°C-8°C, most can be cultivated outdoors. In Jiangsu and Zhejiang areas, it is customary after the Beginning of Winter (around November 7-8) to move Cymbidium ensifolium, Cymbidium kanran, and Cymbidium sinense, which require slightly higher temperatures, indoors for cultivation, and to move spring orchids and Cymbidium faberi with flower buds to corridors or cold-protected areas, to avoid early frost damage affecting flower bud development. After Minor Snow (around November 22-23), move potted orchids grown from pseudobulbs and weak small plants, especially orchids with pure-color petals, gradually indoors, placed on orchid benches near windows to receive sunlight. After Major Snow (around December 7-8), move all potted orchids indoors for care. Before orchids enter the orchid room, clean the area around the orchid pots, which prevents mud from contaminating insect eggs and mold, and also looks clean and elegant. When placing orchid pots, pay attention to reasonable arrangement, facilitating sunlight penetration and ventilation. When terrestrial orchids overwinter indoors, the key is to master temperature and humidity well. Generally, room temperature should be maintained above 7°C-8°C, and for Cymbidium sinense, ideally 10°C-15°C. After orchid pots are brought indoors, if the weather is not yet severely cold and freezing, open south-facing windows around noon, and open small vents on the north side, to facilitate indoor air circulation. In the evening, if indoor temperature is still above 5°C, the small north and south vents can be slightly opened; if below 5°C, all windows should be closed. In deep winter, only on windless sunny days at noon, slightly half-open windows for a little ventilation, and close doors and windows when the sun slightly shifts, and hang straw curtains or cotton cloth curtains in the evening. If temperature continuously drops below 3°C-5°C, a coal stove with chimney pipe can be used for heating. After the Beginning of Spring (around February 3-5), the climate gradually warms, and on clear middays all orchid room doors and windows can be fully opened, but attention should be paid to temperature changes; in the afternoon when temperature gradually drops, south windows should be half-opened and half-closed; before nightfall, close all properly.
During this period, the orchid room temperature should preferably be maintained at around 10°C. If the temperature is on the high side, it will cause early-flowering varieties of spring orchids to bloom early, and flowers also easily wither early. In early spring, one must especially guard against late spring cold, which affects flower bud growth and may even frostbite orchid roots.
After Awakening of Insects (around March 5-6), all spring orchids and Cymbidium faberi without flower buds can come out of the room and be placed on open-air benches. At night, cover the shed frame with reed curtains to prevent frost damage. All orchid varieties with flower buds should still remain in the orchid room for care, and only after Qingming (around April 4-6) can they be moved outdoors for cultivation; but at night, attention should still be paid to preventing late frost. During the indoor orchid cultivation period, especially in severe cold seasons, special attention must be paid to the moisture level of potted orchids. The potting soil should be dry. When to water can be judged by looking at the pot surface: if the surface soil is in a powdery, loose state, while the soil below is still slightly moist, do not wait until the potting soil is completely dry before watering. When watering, first move the orchid pot down and place it on the ground, water along the pot rim water groove. Never let water soak into the leaf cluster. Orchid pots can also be placed in a water vat for shallow soaking for a few minutes, with water limited to reaching the pot's waist. When watering, if water soaks into the leaf sheath, promptly wipe off the water marks with a dry cloth, or let sunlight dry it before moving back indoors. Because orchids are placed indoors for long periods, many dust particles often accumulate on the leaf surface, hindering metabolism. On clear, warm days, around noon, move the pots outdoors into sunlight, use a fine-hole spray can to spray and clean the leaf surface, washing away dust, and after the water marks dry, move back indoors. If the water marks are not dry, the wet parts of orchid leaves easily turn black and wither. When growing orchids indoors, during the heating period, indoor temperature is often on the high side, leaf clusters appear dry, the soil surface in the pot is dry and loose, or the moss on the pot surface looks withered. Then promptly spray some water on pathways and walls, letting it evaporate, to regulate temperature. In summary, for indoor orchid cultivation, whether the orchid plants in the pot or the moss on the pot surface, it is best to maintain green freshness. If you are a hobbyist orchid grower, due to limited conditions, you can use a south-facing sunny spot along a wall outdoors, with one side against the wall and the other three sides built with bricks into a single-slope ground box. The size can be determined by the number of pots. On the sloped surface of the ground box, install wooden-framed glass windows or plastic film windows that can be opened and closed. For orchids with long and tall leaves, place them in the higher space near the wall, on inverted empty flower pots, or on stacked bricks, wooden strips, or cement boards of appropriate height. Low pots are arranged row by row forward. All leaf tips or the tops of encircling leaves must not touch the window glass or plastic film. In severe cold seasons, whenever temperature is too low or on snowy and windy days, the sloped windows must be covered with enough straw curtains or other coverings to prevent cold air from entering. In clear and mild weather, especially after the Beginning of Spring, when sunlight shines, the cold-protection straw curtains can be removed; at noon when sunlight is strong and temperature slightly higher, the window covers can be lifted to create a gap, regulating fresh air. After sunlight shifts, immediately close the window covers. Daily attention must be paid: excessive water droplets must not condense on the window glass, preventing them from dripping into the leaf clusters, as wet parts often turn black and rot, or even die.
3. Planting orchids 1. Planting timing: Whether repotting or new planting, the choice of timing has a great influence on orchid survival, growth, and development. Therefore it is very important. Generally, the more suitable time is the orchid's dormancy period, i.e., March-April, before new shoots emerge from the soil; in terms of solar terms, it is between the Spring Equinox and Qingming. If after new shoots have emerged, operation is very inconvenient, and a little carelessness will break or damage the new shoots. When the orchid's dormancy period is about to end, and new shoots and new roots are at the point of about to grow but not yet grown, planting at this time is best. Shortly after planting, they can put out roots and shoots and resume normal growth. If planted too early, orchids are not easy to revive after planting. If encountering low temperature, cold wave, late frost, or spring thunder, frost damage is often caused. In the Yangtze River basin, orchid rooms rarely have heating in winter. Winter is very cold, so dividing plants in severe winter is not advocated. To facilitate operation during division, the soil can be appropriately dried before division. Let the roots turn white, producing inconspicuous shrinkage, making the originally brittle and easily broken fleshy roots soft and pliable, so that when dividing and potting, not too many roots are broken. For larger orchid nurseries, the planting workload is large, taking a long time. Precious varieties should be scheduled for planting at the best time. General varieties can be postponed or advanced as appropriate.
2. Using orchid seedlings for propagation: For propagation, orchid seedlings that are growing well and free of pests and diseases should be selected.
After orchids have been grown for 2-3 years, the soil or pots need to be changed, and at this time division propagation should be carried out. When repotting, support the bottom of the pot with the palm of the left hand, spread the fingers of the right hand and carefully reach into the leaf cluster of the orchid to block the potting soil, then lay the pot on its side, tilting the body of the pot toward the person, with the lower edge of the pot mouth touching the ground. At this point, lift the pot slightly upward with both hands, so that the lower edge of the pot gently taps the ground, loosening the potting soil, then rotate the pot body to change the contact point where the lower edge of the pot mouth taps the ground, so that the potting soil gradually loosens evenly and separates from the pot. Support the orchid plant with the right hand, and remove the pot with the left hand. If the orchid plant is too tall, it is better to tap the lower edge of the pot mouth against the edge of a wooden chair or cement platform, so that the orchid leaves hang in the air and are not injured or broken. After the orchid potting soil has separated from the pot, lay the orchid seedlings and potting soil flat, so that the soil ball does not suddenly loosen and crack apart, causing the orchid root system to break. Then carefully pat the soil ball gently to loosen it, and gradually shake off the old potting soil. Carefully grasp the pseudobulbs to avoid injuring the leaves and tender shoots, especially protecting the root tips. Cut off leaves that have already turned yellow and withered, decayed bract leaves on the pseudobulbs, and rotten, dried, hollow old roots. However, leaves on pseudobulbs that have new shoots should be retained as much as possible, to promote good growth of the new shoots. For the larger clumps of plants that have been selected and cleaned up, find the natural gap where two pseudobulbs are relatively far apart and easily loosened when shaken by hand, and cut the two pseudobulbs apart. The ancients called this "opening the road." Then hold the bases of the two clumps with both hands, and along the "road" gently shake and slowly pull to divide them into two clumps. Prune the separated orchid clumps appropriately, then soak them for 10-15 minutes in a Topsin solution diluted with 800 times water. It is only suitable to soak the roots, not the leaves; a 1000 times water potassium permanganate solution can also be used for disinfection. Be careful to disinfect only the wounded parts, then air-dry the orchids in a cool, ventilated place. When the orchid roots have become soft and easy to bend, they can be planted. Generally, in clear weather, air-drying for half a day is enough; of course, they must not be dried too much.
3. Planting procedure: For the separated orchid clumps, do not divide them too sparsely. Each clump should have at least 3-5 seedlings, and it is best to keep one-year-old plants, two-year-old plants, and three-year-old plants in the same clump.
(1) Padding the pot.
Cover the drainage hole at the bottom of the pot with a piece of tile, then gradually fill with bricks, tiles, or shells, with large gaps filled with mud granules or bean-sized stones, generally about 1/2-1/3 of the height inside the pot. The remaining clear height above is about 10-15 cm, reserved for the cultivation soil layer. Its specific height should be determined according to the type of orchid, the length of the orchid roots, and the height of the pot. The padding material should not be filled too densely or too solidly; some pores should be retained. Practice has proved that some new roots can grow well in the pores of the padding layer.
(2) Planting.
On the padding layer, first fill in 2-3 cm of cultivation soil, press it lightly with the hand, then place the orchids upright on top. According to the size of the plants and the pot, several single plants, 2 clumps, 3 clumps, or more clumps can be planted in one pot. 3 clumps are suitable for planting in a tripod arrangement. 4 clumps can be planted in a square. 5 clumps are suitable for arrangement in a plum-blossom shape. The orchid roots should spread naturally, and the leaves should spread in all directions. Slowly place the orchid roots into the pot, so that the orchid roots spread naturally and try as much as possible not to scrape against the inner wall of the pot. After the orchid plants are put into the pot, gradually fix the posture of the orchid plants. If one clump is planted in a pot, the old pseudobulbs should be placed toward one side, so that the new shoots have room to develop. If multiple clumps are planted in one pot, the old pseudobulbs of each clump should be relatively gathered in the middle of the pot, so that new roots and new shoots have enough space to develop outward.
(3) Filling soil.
When planting, support the leaves with one hand and add nutrient soil with the other, holding the base of the orchid plant and lifting it slightly upward to spread the root system, while shaking the orchid pot. Let the cultivation soil go deep into the root zone; continue adding soil, and shake the orchid pot to adjust the position and height of the orchid plant. Press with the hand along the edge of the pot, but do not press too hard or the roots will be injured. Continue adding soil and pressing until the soil surface is 2-3 cm above the pot mouth, slightly resembling a steamed bun shape. The cultivation soil should cover all the orchid roots, covering up to the base of the pseudobulbs. As for the depth of soil filling, tradition holds that: Cymbidium goeringii is suitable for shallow planting, and Cymbidium faberi is suitable for deep planting, but generally the degree is that the leaf bases on the pseudobulbs are not buried. When newly collected orchids grow in the wild, the plants leave obvious markers above and below the soil surface, and these markers can be used as the standard. The size of the flower pot should also match the size and number of the plants; neither should the pot be large while the plants are small and few, nor should the pot be small while the plants are large and many. Generally, the number of plants should be based on the principle that after 2-3 years they will just fill the pot. The size of the plants should match the height of the pot. This is beneficial to growth and also meets ornamental requirements.
(4) Top dressing.
After planting is completed, a layer of small stone granules or green moss can be spread on the surface of the potting soil, preferably high-quality moss from under the forest. It is not only beautiful, but can also regulate moisture, and can also protect the leaf surface from being polluted by muddy water, so that new shoots will not rot at the heart due to infection by pathogens in the soil; in addition, it can also reduce the washing away of the potting soil by rainwater and keep the potting soil loose.
(5) Watering.
After planting is completed, water immediately for the first time. The potting soil must be thoroughly moistened. The water droplets should be small, and the impact force should not be strong. If placing it in a basin of water to soak, never soak it for too long. Once the potting soil is soaked, immediately take the orchid pot out, then move it to a shaded place for care.
4. Care and management after planting. Although mastering the art of planting orchids is very important, managing and caring for orchids well is even more difficult, hence the saying "three parts planting, seven parts care." The care of orchids requires understanding the environment, accumulating care experience, and patience and carefulness. The most important thing is to understand the laws of orchid growth and development: when they sprout, when they grow leaves, when they bloom, and when they go dormant. Then carry out care and management from the aspects of temperature, humidity, watering, fertilizing, ventilation, plant protection, cherishing leaves, and protecting flowers, and you will certainly be able to grow orchids well.
1. Cherishing leaves. Orchid leaves are soft and beautiful but not weak, upright but not stiff.
Orchids are moving and lovely, but good flowers do not bloom often, and when the flowers fall there is nothing to be done; yet orchid leaves remain green through all four seasons, forever full of vitality, giving people enjoyment that continues all year round. The elegance of orchids is both revealed in the flowers and entrusted to the leaves.
And lush leaves are also the prerequisite for good flowers. When the leaves are healthy and lush, the plant itself produces abundant nutrition, so the flowers are numerous and beautiful. If the leaves are damaged while the flowers are many, it is merely a sign of rapid decline. The key to cherishing leaves is first of all to control the degree of shading, air humidity, appropriate water and fertilizer, and maintain good ventilation. Make the orchid leaves lush and healthy, verdant and glossy. Also strengthen pest and disease control, and prevent wind and rain attacks and mechanical damage. In addition, preserve the leaf tips. The ends of orchid leaves are like sword tips, brush tips, and eyebrow tips, able to convey meaning and spirit. Losing the leaf tip makes them appear abrupt and dull. The key to preserving leaf tips is to ensure the water and nutrients needed by the orchid are sufficient, and the potting soil is loose and breathable, so that the root system is well developed and intact, the plant grows vigorously, and no scorched tips occur. Some people believe that a sign of orchids being grown well is that the leaf tip can pass through the eye of a needle, which refers to the leaf tip being intact and the tip undamaged. The leaf tip shapes of different orchid species differ: some are acuminate, some obtuse and rounded, some emarginate, and some upturned. As for leaf color, some orchid varieties are valued as precious and rare for their gold tips or silver tips (that is, the leaf tips are yellow or white). This is another layer of interest in leaf appreciation regarding leaf tips. In daily care, attention should be paid to protecting orchid leaves. During operations, be light, nimble, and careful; do not bump the orchid leaves, and maintain their natural posture.
Contaminated leaves should be carefully cleaned, and sprayed water must not accumulate in the center of the leaf fan. Withered yellow old leaves and diseased leaves should be cut off in time. For partial cutting of orchid leaves, a slanted cut can be made at an appropriate place, and the resulting pointed angle should be less than 30. Some also cut twice, but it must not be cut into a flat head.
2. Protecting flowers. After flower buds emerge from the soil, if there are too many, they will consume excessive nutrients from the mother plant, hindering the formation and robust growth of leaf buds. Excess thin and small flower buds should be removed as early as possible. For each orchid seedling, keep one flower bud.
Each pot should retain 3-5 flower buds. Appropriately retain flower buds according to the orchid variety, the size of the pot, and the number of seedlings. In order to protect and develop precious varieties, all flower buds can also be removed to let them multiply luxuriantly. During the period from flower bud elongation to the flowering period, maintain moderate light, so that the flower color is bright and full, rich in luster, and sufficient in fragrance. If the light is too weak, the flower color will be pale and lack luster. Flowers that remain open too long consume nutrients and hinder sprouting, leaf growth, and flowering the following year. Cymbidium goeringii flowers bloom for about half a month; after they fade, the flower scape should be cut off in time. For Cymbidium faberi flowers, when the last flower of the inflorescence has been open for 1 week, cut off the inflorescence. When breaking off the flower scape, steady the leaf base with one hand and press the flower scape to one side with the other, and it can be broken off from the base, or it can be cut off. The removed flowers and stems can be placed in a vase and still enjoyed for many days. Generally, orchids are not allowed to be pollinated and set seed after flowering, especially not the less robust and precious varieties, otherwise flowering the next year will be affected. If hybrid breeding is to be carried out, artificial pollination should be performed at the appropriate time. And manage the maternal parent carefully so that the seeds are full and ripe.
3. Temperature. Most regions of our country are in the temperate and subtropical zones, while orchids generally come from places with a mild and humid climate, relatively high annual average temperature, and a relatively long frost-free period. In Northeast and Northwest China, orchids are rarely grown, mainly because of temperature constraints. The northernmost-distributed Cymbidium plants in our country are Cymbidium goeringii and Cymbidium faberi. Along their distribution line, there is frost or short-term snow cover in winter, and summer temperatures are relatively high. However, because orchids mostly grow in mixed broadleaf and coniferous forests or in bamboo forests, the trees both block the summer sun and resist the winter cold wind; even in places covered by snow, the impact on orchids is not great, because snow actually protects orchids through the winter. The ground temperature under snow is generally not lower than 0°C. In our introduction and domestication of Cymbidium ensifolium and Cymbidium kanran, we have already moved them 600-1000 km northward from their places of origin, and have carried out large-scale ground planting. It can be seen that the survival ability and adaptability of orchids are still relatively strong. In most areas of Northeast, Northwest, and North China, winters are too cold, and outdoor orchid cultivation is unsuitable. From mid-to-late October to late April of the following year, for half a year, orchids all need to be moved indoors or into greenhouses for cultivation. In the lower reaches of the Yangtze River, orchids also need to be brought indoors in winter for cultivation or heated in sheds. In Fujian, Guangdong, Guangxi, Yunnan, Sichuan, Taiwan, China and other provinces and regions, Cymbidium kanran and Cymbidium ensifolium generally do not need indoor overwintering in winter. In Jiangxi, Hunan, and parts of Sichuan, certain measures are still needed in winter to protect orchids.
Orchid temperature requirements: The temperature for orchid seed germination is: 21°C-25°C during the day, 15°C-18°C at night. The temperature required for grown plants of terrestrial orchids is 20°C-22°C during the day and 13°C-0°C at night.
During the winter dormant period of orchids, the temperature can be lowered. For example, Cymbidium goeringii and Cymbidium faberi require a minimum winter night temperature of 4°C-6°C, and dropping to 0°C is also acceptable. The leaves of the plant can even drop to minus 2°C-3°C under dry conditions without harm. Orchid flowers develop from flower buds, and flower bud differentiation is closely related to temperature and light. Previous generations did much research on orchid flower bud differentiation, and concluded that a low temperature of 12°C-13°C is sufficient to cause flower bud differentiation, and the relationship with day length is not very great. However, the more light the orchid receives, the more pronounced the effect of low temperature on flower bud formation. Therefore, from late spring to autumn, placing orchids outdoors for cultivation is better than indoor growth and development. The purposes of regulating temperature are mainly 3 aspects, namely: preventing cold in winter, preventing summer heat, and changing the flowering period. When the winter temperature is below 0°C, orchid leaves and flower buds are prone to freeze damage, with water-soaked black spots appearing on the leaves and flower buds wilting. If the temperature drops suddenly and sharply or there is a particularly severe frost, the damage is even greater. But winter temperatures that are too high are also not good, because orchids are in a dormant state in winter, and too high a temperature will disturb dormancy. In summer, if the temperature is too high and orchids suffer from summer heat, the leaves turn yellow, become rough and lack luster, and are prone to disease invasion, often with the leaf base beginning to rot. The flowering period of orchids is very obviously affected by temperature. Under general conditions, appropriately raising the temperature can make them bloom earlier. For example, under cultivation conditions in plains and cities, the flowering period of orchids is often 15-30 days earlier than under the original wild conditions. Using this biological characteristic, the temperature can be appropriately regulated to advance the flowering period by half a month to one month. Especially for species that bloom in spring, flower buds have generally already formed in July-September of the previous year. Once they have passed through the winter dormancy stage, appropriately raising the temperature can make them bloom early and catch the Spring Festival holiday. But it must be pointed out that raising the temperature must be done step by step. Experiments show that sharply raising the temperature instead produces an inhibitory effect and delays the flowering period.
Methods of regulating temperature:
Temperature has a great influence on orchid growth and development. If the temperature is too high, respiration speeds up and nutrient consumption increases; if too low, enzyme activity decreases, synthesis is low, and growth and development slow down. What is important is that the daily temperature difference and seasonal temperature difference must form, so that sprouting and flowering can occur. In temperature regulation for domestication and cultivation, we adopt the principle of being similar to the original orchid production area. In summer, double-layer shading nets are used to shade the orchid nursery, and the cooling effect is obvious. When the air temperature reaches as high as 35°C, the temperature in the orchid nursery is only 31°C-32°C. In winter, plastic greenhouses are used to keep warm. When the air temperature drops to 0°C, the inside of the plastic shed can still remain at 6°C-8°C. The winter temperature difference is smaller than in the open field, which is both beneficial for nutrient storage and prevents freeze damage. In addition to building soil orchid sheds and orchid rooms, temperature regulation can also be done by planting trees, shrubs, vines, and lawns around the orchid nursery. In summer, they can absorb part of the solar radiant heat, and in winter they can reduce the loss of heat from the ground and air. Taking lawn as an example, according to measurements, in winter the air temperature over grassland is higher than over bare ground, with a maximum daytime difference of up to 4.4°C, which helps avoid freeze damage; while in summer the air temperature over grassland is much lower than over cement ground, which helps prevent summer heat and lower temperature. In summer, it is suitable to spray or sprinkle clear water in the air, on the ground surface, on flower stands, and on orchid leaves. Because water absorbs part of the heat when evaporating, it can play a role in cooling and preventing summer heat; similarly, expanding the water surface nearby also has this effect, such as ponds, reservoirs, ditches, and water vats. Greenhouses need to hang curtains on the glass to block light and prevent heat. In hot weather, more attention should be paid to ventilation and strengthening air convection for heat dissipation, partially lifting the covering on the shed; for orchid rooms, open doors and windows to avoid the accumulation of hot air. In temperature regulation, in addition to air temperature, soil temperature should also be noted. Orchid roots grow in the soil, and the temperature of the potting soil has a direct impact on their physiological functions. Under general conditions, soil temperature and air temperature are positively correlated. When the air temperature is high, the potting soil temperature also rises, but the process of change is relatively slow. First, prevent direct sunlight from shining on the flower pot and heating the soil and pot, which would burn the orchid roots close to the pot wall; also note that when watering, the water temperature should be close to the soil temperature and should not differ too greatly. There is also a question worth exploring, namely the relationship between artificial protection and the orchid's own adaptability. Like all plants, orchids also have adaptability to the external environment. They are not innately delicate. Therefore, when orchid growers protect orchids from summer heat and cold, their measures should be moderate. Shading too densely and for too long will inevitably weaken their resistance. In our orchid nursery, the Cymbidium kanran and Cymbidium ensifolium introduced and domesticated from 600-1000 km away in the south are not only given protection, but are also gradually allowed to strengthen their resistance and gradually adapt to the new environment.
4. Humidity. Humidity generally refers to relative humidity, commonly expressed as a percentage.
Orchids have no fibrous roots, much less root hairs, so their water-absorbing surface is small; on the contrary, orchid leaves grow in clusters. Leaf transpiration is relatively large, and only when the air is humid can the balance between water absorption and transpiration be maintained. In the growing season in the places where orchids originally grow, rainfall is abundant and the air is humid, with relative air humidity all above 80%; especially Cymbidium sinense grows beside streams, often with dense water mist, and relative humidity is around 90%. One important reason why growing orchids in the north is difficult is dry air. Generally, growing orchids in urban homes and on balconies is not easy to succeed at, and insufficient humidity is also a major factor. When air humidity is low, orchid leaves are rough and dull without luster; when air humidity is suitable, the leaf surface is moist and green. Usually the humidity required during the orchid growing period cannot be lower than 70%, and in the winter dormant period it is about 50%; at night the air humidity should be somewhat higher than during the day. Humidity and ventilation are two relatively contradictory factors. Too much ventilation lowers humidity. In winter and spring in the north, dry winds blow frequently and humidity cannot be maintained, which is unfavorable for orchid growth, so ventilation should be appropriately reduced.
Methods of regulating and increasing air humidity:
Plant many trees, bamboo, and grass around the orchid nursery. The root systems of these plants can absorb large amounts of water from underground and then release it through transpiration from the leaves at the surface. They can also retain surface water, gradually transpire it, and increase the content of water molecules in the air, thereby increasing air humidity. When the ground is dry, sprinkle water on the ground, benches, and walls, which also has the effect of lowering temperature. Spraying or sprinkling water can also be done in the air space of the orchid growing site or on the leaf surface. However, spraying or sprinkling water on the leaf surface should not be done at night. If it is necessary to sprinkle water on the leaf surface in the evening, it must be ensured that the leaf surface can dry again by night. In southern China, there are sometimes continuous rainy days, especially in the plum rain season when humidity is too high, so doors, windows, and coverings should be opened for ventilation. Orchids like warmth and moisture. When humidity is high and ventilation is good, orchids will grow robustly; but when the temperature is low and there is no ventilation, water vapor will condense into droplets, which is harmful to new shoots and can easily cause disease, so low temperature and high humidity should be avoided. In our seedling beds for large-area ground planting of orchids, bricks are laid around, and moss is planted on top. Bricks and moss have very strong water absorption and moisture retention capacity. This economical and convenient natural humidification measure is very effective.
5. Watering. When watering, attention should be paid to issues such as water quantity, water quality, water temperature, watering time, and watering methods.
In the classification of xerophytes, hydrophytes, and mesophytes, orchids belong to mesophytes and do not need excessive water, so the potting soil should not be too wet. This is determined by the structural characteristics of orchid roots and stems. The pseudobulbs of orchids are plump, with a cuticle on the surface, and the epidermal cells are thickened to form stone cells, with vascular bundles scattered throughout the stem. The pseudobulbs can store nutrients and water and are not easy to evaporate. Orchid roots are mostly fleshy, with the outermost layer being velamen tissue, and the cells of the velamen tissue are elongated tubular and polygonal. When the velamen tissue cells mature, the protoplast disintegrates, and thickened stripes develop on the cell walls. The function of the velamen tissue is to protect the cortex, absorb water, and reduce and protect against the loss of water inside the cortex. Therefore, orchids should not be watered too frequently, and the potting soil should not be too wet, so as to avoid root rot. In addition, judging from the original production areas of orchids, orchids mostly grow on hillsides, on both sides of ridges, and in rock crevices. These places have good drainage and no danger of accumulated moisture and waterlogging. It is precisely by adapting to such an environment that orchid roots and stems are structured to store and retain water and nutrients.
Principles of watering orchids:
The following conditions must be relied upon:
(1) The type of orchid.
Epiphytic orchids and those with aerial roots can be watered less. For example, Cymbidium hookerianum has aerial roots and can absorb water from the air, so it does not need too much watering. In addition, those with thick cuticles on the leaves should be watered less. For example, the cuticle on the leaves of Cymbidium ensifolium 'Tiegusu' is thick, water evaporation is low, and watering must be strictly controlled.
(2) The growing season of the orchid.
In spring, the temperature gradually rises, and it is the season for new shoots to sprout, so watering should be timely. Water once a day or every other day to keep the potting soil moist. If water is lacking during this period, flowering will be late and the shoots will not be strong. In summer, the temperature is high and water evaporation is large. This is the expansion period for leaves, root emergence, and root and leaf elongation. Water once every morning. In the evening, if the potting soil is dry, some water can be added to moisten the potting soil, thoroughly moisten the leaves, lower the temperature, and reduce nutrient consumption, so as to facilitate growth and development. Entering autumn, the temperature gradually drops, orchids grow slowly, and the dryness and wetness of the potting soil should be observed every day. Water when dry, and leave it when wet. In winter, orchids enter the dormant period. The potting soil should be slightly dry, and watering should be reduced or omitted, but attention should be paid to the potting soil to prevent excessive water loss from the potting soil that would instead draw water out of the roots. At the transition between winter and spring, after Cymbidium goeringii has formed buds, the flower buds begin to elongate, so the potting soil should also maintain a certain humidity. If the potting soil is too wet in winter, the water content of the orchid plant increases, which easily causes freeze damage.
(3) The growth condition of the orchid.
If the orchid grows strongly and the roots are good, it can be watered more; otherwise, reduce as appropriate, and diseased plants should have their water even more controlled. When orchids are sprouting and growing, more water can be given; after sprouting, it can be gradually reduced. When new shoots gradually mature, water should again be somewhat reduced. When flower buds appear, slightly more water may be given; but during the flowering period, water should not be too much, in order to prolong the flowering period. After the flowers fade, watering should be stopped for several days, so that the potting soil becomes slightly dry and the orchid enters a slight dormancy, and then water again.
(4) The condition of the flower pot and the plant.
That is, water according to the texture and size of the flower pot. Water more for clay pots and large pots, and less for porcelain pots and glazed pots. Water more when there are many potted plants or when ground-planted orchids are dense.
(5) The dryness and wetness of the potting soil.
The bases for watering, such as season, plant, weather, flower pot, and soil quality, can all be comprehensively reflected by the degree of dryness and wetness of the potting soil, so the dryness and wetness of the potting soil is the direct and intuitive basis for watering.
It can be judged by observation and touch. If the potting soil becomes hard, the color becomes lighter, and the moss on the pot surface is dry and wilting, it indicates that the soil is dry. It should be watered immediately. If the potting soil is dark in color, has moisture, and the moss is moldy, it is a sign that the soil is too wet, and water should not be added. Generally, the suitable soil moisture content is 15%-20%.
(6) Watering time.
Generally speaking, in spring and autumn it is suitable in the morning; during the hot midsummer period, it is suitable around sunrise and around sunset; in early winter and early spring, it can be watered after the sun is at its height and the temperature is slightly warmer. During the period when they are brought indoors to overwinter, watering must be done at noon on clear days. But care should be taken to avoid wetting the leaf surface or letting water enter the leaf sheaths. Among the people there are some very valuable experiences in watering orchids. For example, for Cymbidium goeringii and Cymbidium faberi, there is the experience of "not dry in autumn, not wet in winter" and "likes moisture in spring, likes slight moisture in summer and autumn, and needs moisture with some dryness in winter." This shows that orchids have different requirements for water at each growth and development stage, and management should be adapted to local conditions and flexible. Generally after the Beginning of Spring, the climate gradually warms, the flower buds expand, and the soil should remain moist, with spraying once every 2-5 days. After Awakening of Insects, for non-flowering Cymbidium goeringii and Cymbidium faberi grown in the open, wind and sun make the pot water dry easily, so daily watering should be frequent, but the amount should not be too much. Water once every 2-3 days or a small amount once a day. After the Beginning of Summer, for all orchids that have finished flowering (including Cymbidium kanran and Cymbidium sinense), the soil should be somewhat drier, because after flowering most have a short dormant period, grow slowly, and evaporate less from the leaf surface. From June, the weather gradually becomes hot, and the young shoots (that is, young buds) grow faster. At this time, more attention should be paid to soil humidity, and clear water should often be sprayed on orchid leaves and orchid benches to create a moist microclimate, which is beneficial for the young shoots to elongate and spread leaves. During the plum rain season, watering should be controlled to reduce disease occurrence. Leaf-art varieties and some petal-type seedlings are even more prone to disease, so even more attention should be paid. During the three fu periods, the climate is hot. In addition to strengthening shading, the soil moisture should also be carefully maintained, and clear water should be sprayed on the leaves and pot surface around sunrise every day. After White Dew, it gradually turns cool in autumn, and with the moisture of night dew, the growth momentum of new plants pauses, and orchid buds break through the soil and grow slowly. At this time, the amount of irrigation can be reduced; but when the potting soil is found to be dry, it must be watered to the point of moistening. In late autumn, new plants have changed from fresh green and tender green to deeper and darker shades. The flower bud sheaths are all visible. It is necessary to prevent prolonged rain and excessive moisture, and reduce the rotting of the sheaths (that is, decay of the bud sheaths). Measures should be taken to avoid rain and receive more sunlight.
(7) Water quality and water temperature for watering.
For watering orchids, it is best to use stored rainwater, which is the cleanest and also neutral; river water is next; well water contains minerals and is mostly alkaline, so it is relatively poor; tap water contains disinfectants and is most unsuitable for orchids. If tap water must be used, it should be stored in a pool for more than 24 hours. It is even better if it can be exposed to sunlight, and after the disinfectant has settled or decomposed, take the clear water on top to water the orchids. In addition to this storage treatment, there is also an activation treatment, which is to raise fish, algae, chlorella, red floating algae, and other aquatic organisms in the pool where tap water is stored, in order to improve water quality. But note whether the fish have diseases, to prevent water quality pollution. The temperature of the potting soil can directly affect the water-absorbing function of orchid roots. Therefore, the temperature of the irrigation water should be very close to the potting soil temperature and air temperature. In hot summer, after the flower pot and soil have been heated by direct sunlight, if cold water is suddenly poured on them, the temperature difference between the two is too great, which will destroy the normal absorption function of the root system and affect physiological balance. Therefore, in summer, orchids should be watered in the morning and evening, when the water temperature and soil temperature are close. Reservoirs or water storage vats are best half-buried in the soil, plus shading, so that the water temperature in summer will not be too high.
(8) Watering methods.
Common orchid watering methods include watering, spraying, and soaking. Usually a watering can, ladle, or hose is used for watering. When watering, slowly pour from the edge of the pot, so that the water gradually seeps downward and toward the center. Never pour it suddenly into the center of the leaf fan, and do not let the water splash up potting soil and pollute the leaves. Spraying should moisten the entire pot, and it must not be half-watering, that is, with water only on the surface layer while the lower layer gets none. If half-watering is done for a long time, the surface is wet while the interior is dry, causing some orchid roots to be unable to absorb water for a long time and to shrivel, while the upper orchid roots instead turn upward and grow, scattered and coiled in the surface soil. Many people, for convenience and to save trouble, connect a rubber hose directly to the tap and pour water into the orchid pot. This is very harmful: first, the tap water has not been treated, and the bleaching agent is harmful to orchids; second, the water temperature and soil temperature differ greatly; third, watering cannot be differentiated according to different situations. The spraying method is to use a spray pot to spray water on the leaf surface, which can both increase air humidity and soil moisture, and also wash away dirt on the leaf surface. This method is often used during the orchid growing season. Each spraying should not be too much, with the degree being that the leaf surface is wet but water does not run off. If too much water is poured into the leaf center and remains for a long time, it will rot the new seedlings. The nozzle holes of the spray pot should be fine and dense, and the water droplets should be fine and uniform. The soaking method, also called seep-watering, is to place the bottom of the orchid pot into shallow water and let the water gradually moisten the potting soil. The soaking time must not be too long; as soon as the surface soil is seen to be moist, take the orchid pot out immediately. This method can keep the orchid leaf surface clean. In dry seasons, the orchid pot can also be placed in a shallow tray, and the flower pot absorbs the accumulated water in the tray, which then moistens the potting soil, thus maintaining relatively stable soil moisture. The disadvantage is that the bottom hole of the flower pot is blocked by water, and air permeability is affected to a certain extent.
6. Light and sunshine. Light refers to the quality and quantity of sunlight, including wavelength, spectral composition, and light intensity. Sunshine refers to the duration of sunlight; generally, illumination for more than 14 hours is long-day, and less than 14 hours is short-day. Among plants, those that require long-day conditions to flower are called long-day plants; conversely, those that require short-day conditions to flower are called short-day plants. Light and sunshine are closely related to the growth and development of orchids.
Orchid requirements for light:
There is a floral proverb: "Shade for camellias, sun for peonies, half shade and half sun for four-season orchids." This shows that different flowers and trees have different sunlight requirements, and orchids need half-shade and half-sun light conditions. The effect of light on leaf color: orchids have long grown in mountain forests and have developed a shade-tolerant habit, disliking direct strong light. When light is too strong, the leaf color becomes pale green; if suddenly exposed to strong light, the leaf color quickly turns yellow, the leaf surface becomes rough, and even the leaves scorch. With moderate light, the leaves are green with fine texture and luster; with too weak light, the leaf color is dark green and loses luster. The effect of light on sprouting: the intensity of light has a direct impact on the number of leaf buds and flower buds, the time they emerge from the soil, and their growth condition. With too weak light, orchids produce more leaf buds and fewer flower buds, and their growth is poor. Therefore, starting a period before flower bud formation, appropriately increasing light can promote flower bud differentiation and achieve the goal of more flowering. The effect of light on flower color and flowering: the flower color of orchids is mainly determined by flower pigments, and violet light and ultraviolet light in light are the main light energy forming orchid pigments. Therefore, when light is strong, the flower color is deeper and more vivid; when light is too weak, the flower color is extremely pale, and compared with normal, it may be mistaken for another variety. For example, in ancient times in Ningbo, Zhejiang, there was a kind of snow orchid produced on shady, north-facing mountain slopes. If planted in a pot and exposed to even a little sunlight, it would turn green, and so it was regarded as rare and precious. Today it is often encountered during wild collection, and it can also be obtained by artificial cultivation. Some people use this to practice fraud and pass it off as a new variety, and those with insufficient experience are often deceived. If other conditions are the same, orchid pots placed in a position with stronger light bloom first. This is because the accumulated illumination and accumulated temperature first reach a certain value. Some people have experimented and found that extending the light period to 14-16 hours can promote earlier flowering in medium plants and small seedlings; but for mature orchid plants, a light period of no more than 8 hours can promote flowering. For orchids that bloom in winter, short days and long nights and low temperature conditions should be provided to promote flowering. For orchids that bloom in summer, long days and short nights and high temperature are required to promote flowering. For orchids with flower buds, to promote earlier flowering, the light period and temperature can be appropriately increased. In a small room, using a 100-watt light bulb can raise the room temperature by 3°C-5°C, which can promote earlier flowering. The relationship between light and leaf art: leaf art is the cultivation technique in which lines or spots appear on the leaves. Leaf art is related to light. Changes in light can be used to promote changes in leaf art. The method is to use robust growing orchid seedlings, with more than three plants connected together. Before 9 o'clock in summer and before 10 o'clock in winter, expose the orchid pot to sunlight, insert a thermometer into the pot, and when it reaches 30°C, move it into the shade. When it drops to 25°C, move it out again into sunlight. Repeat this over a long period. One shade and one sun, one cold and one hot, is beneficial to the appearance of variable factors within the leaves. Over months and years, hard work pays off, and variegated leaves may appear. But this must be premised on the existence of recessive factors for leaf art within the orchid leaves; the change in sunlight merely promotes their manifestation.
Bases and methods for regulating orchid light:
Liking half-shade and half-sun light is a common characteristic of most Cymbidium plants, but there are also differences among orchid species. Species that bloom in spring, such as Cymbidium goeringii, Cymbidium goeringii var. longibracteatum, and Cymbidium goeringii 'Songchun', need relatively weaker light, and the shading degree should be controlled between 70%-80%. Species that bloom in summer and autumn, such as Cymbidium faberi 'Xiahui' and Cymbidium ensifolium 'Qiusu', need slightly stronger light, and their shading degree should be controlled between 60%-70%; Cymbidium sinense needs about 85%. The light duration and intensity in spring, summer, autumn, and winter are all different and should be treated separately, adjusting the shading degree well. Within a single day, morning and evening sunlight can be allowed to shine on them, while the harsh midday sun must be shaded and regulated, and on cloudy days the shading degree should be reduced. It is worth noting that after summer rainstorms, or when it first clears after long rain, orchid pots must not be exposed to the sun. Previous generations' experience: if exposed to the sun right after rain, the water in the pot becomes hot, which scalds the leaves and injures the roots. Although orchids are relatively shade-tolerant, they also have phototropism. In the same cultivation site, the flowers and leaves on the sunny side are always somewhat more luxuriant. Over time, the growth of flowers and leaves becomes uneven and leans to one side. For symmetry and beauty, the direction of the orchid pot should be rotated and adjusted at intervals. If it is for the special needs of shaping or composition, in order to express a specific poetic and pictorial meaning, the position of the light source can also be used to strengthen the tendency of flowers and leaves, achieving the beauty of dynamic balance, which can satisfy appreciation needs. To regulate shading degree and light duration, there are usually the following methods: Buildings - build greenhouses, orchid pavilions, waterside pavilions, and orchid corridors to place orchids, using the light-transmitting and sun-shading properties of such buildings to regulate light. As long as the orchid pots are placed appropriately, the expected effect can be achieved; in the sunny parts of these buildings, bamboo curtains or shading nets can be hung for regulation. For potted orchids kept on balconies, moving them in and out can regulate light. Although it is laborious and tiring, it also cultivates enjoyment; combining flower growing with fitness, the joy is within it. Building sheds - shade sheds can be built with bamboo, wood, angle steel, and other materials, covered with bamboo curtains, plastic film, shading nets, and so on. Our method of regulating light intensity is to set up bamboo frames in the orchid nursery, with double-layer shading nets of 50%-70% shading rate on top. The upper layer is relatively fixed and is only rolled up in winter, while the lower layer can be put down or taken up. In midsummer use double layers, in spring and autumn use a single layer; at noon on clear days in summer and autumn use double layers, on cloudy and rainy days use a single layer. In winter, it depends on the situation: on clear days put down the lower layer, on cloudy days roll up the lower layer, because in winter the light change inside the plastic greenhouse must not be too great; if too great, temperature and humidity will also change accordingly, which is unfavorable for orchid dormancy. In addition, before orchid flower buds are ready to bloom, they must have moderate diffused sunlight, otherwise the flower color will be dull and not show its beauty. Building racks - on the orchid cultivation site, build bamboo racks, wooden racks, or reinforced concrete racks, and let vines such as grapes, honeysuckle, morning glory, Chinese trumpet creeper, and cypress vine climb and spread over them. This can both shade and be beautiful, practical, and economical. Deciduous vines shade in summer and let light through in winter, which is a natural regulation. Planting trees - around the orchid nursery, select and plant evergreen trees, deciduous trees, bamboos, and so on of different heights in combination to regulate light intensity.7. Fertilizing. Orchid roots have no fibrous roots, and there are symbiotic bacteria inside the roots.
The root fungi absorb mineral nutrients from outside and supply them to the orchid, while the orchid root cells provide water and organic nutrients to the root fungi, forming a mutually beneficial symbiotic relationship in which they coexist. But they must maintain a stable balance between them in order to grow luxuriantly. Preparing suitable nutrient soil and fertilizing appropriately to maintain the balance between the two can promote robust orchid growth. Previously some people thought that orchids grow in the mountains and are naturally pure and refined, and could be maintained with clear water and fresh air. Others loved orchids too deeply and were too impatient, often applying high-efficiency, high-concentration heavy fertilizer, causing results contrary to their wishes. Therefore, we must seriously explore scientific and reasonable fertilization.
(1) Types of fertilizer.
Fertilizers can be distinguished by their effective components, fertilizer properties, and fertilizer usage. By effective components, they are mainly nitrogen fertilizer, phosphorus fertilizer, and potassium fertilizer. Nitrogen is the main component of cell nuclei and proteins, and is also an indispensable element in forming chlorophyll. Nitrogen fertilizer can promote lush and robust orchid leaves; otherwise the leaves droop and soften, sprouting is difficult, and the reproduction rate is low. Commonly used nitrogen fertilizers include compost, human and animal manure and urine, urea, green manure, ammonium sulfate, and ammonium nitrate. Phosphorus is also a main component of cell nuclei, directly affecting cell division, chlorophyll formation, and protein synthesis and transformation within plant cells, and can promote flower bud differentiation and growth, and promote large flowers, vivid color, and strong fragrance. Commonly used phosphorus fertilizers include superphosphate, potassium dihydrogen phosphate, phosphate rock powder, bone meal, and rice-washing water. Potassium directly participates in photosynthesis, can make cell physiology normal, and is also related to the synthesis of carbohydrates, proteins, and fats. Potassium fertilizer can make orchid stems, leaves, and roots grow robustly, make the leaves tough and not easy to break, and enhance cold resistance and disease resistance, and can also increase the fragrance of the flowers. Commonly used potassium fertilizers include plant ash, potassium sulfate, and potassium dihydrogen phosphate, all of which are fertilizers containing more potassium. In addition to the three main elements nitrogen, phosphorus, and potassium, orchids also need various trace elements such as calcium, magnesium, iron, boron, and zinc. These can be satisfied in the prepared cultivation soil and generally do not need to be added separately. The demand for nitrogen, phosphorus, and potassium is relatively large, and must be solved through fertilization, turning over, and changing soil. By fertilizer properties, they can generally be divided into organic and inorganic fertilizers. Organic fertilizers include compost, green manure, barnyard manure, and cake fertilizer. Before use, organic fertilizer must be fully fermented, and the fermentation time must be at least more than one month. Organic fertilizer can improve soil structure, increase soil humus, make soil air permeability and water retention good, and its fertilizer effect is also long, able to continuously decompose long-acting nutrients for orchid absorption. Inorganic fertilizer, also called chemical fertilizer, has high nutrient content, is clean and odorless, does not need fermentation, and can be diluted for use immediately. It is convenient and has a quick fertilizer effect, but it does not last long, and long-term use can worsen soil structure. Generally, orchid growers oppose the use of chemical fertilizers. In fact, if orchids are mainly given organic fertilizer and supplemented with chemical fertilizer, the effect is still very good. By fertilizer usage, they can be divided into base fertilizer and topdressing. Base fertilizer is the fertilizer added when preparing cultivation soil or before planting, such as leaf mold, green grass compost, and chaff soil. These are both cultivation media for orchids and base fertilizer. Silkworm droppings, human and animal manure, cow dung, bone meal, hair, cake fertilizer, and so on can also be used as base fertilizer added to the bottom of the pot or turned under the soil as base fertilizer, but chicken manure and human manure are taboo.
(2) Topdressing is fertilizer applied during the growing season after orchids have been planted.
Generally, orchids are only repotted and given new soil after 2-3 years of planting. During the interval, nutrients must be supplemented, so topdressing should be applied.
Time of fertilizing:
During the spring and summer growing period of orchids, to make orchids grow robustly and vigorously, more nitrogen fertilizer can be applied. For leaf-art varieties, apply less nitrogen fertilizer or none, because dark green leaf color will affect the appreciation effect of leaf art. Do not fertilize when the summer temperature is above 30°C, because the potting soil temperature is relatively high, water evaporates too quickly, and the concentration of residual fertilizer increases, which is harmful to growth. If fertilized too frequently in summer, it easily stimulates autumn shoots, and the plants that grow later will be short and weak, and the next year's spring shoots will be inhibited as a result. Do not fertilize when the temperature is below 10°C, because at this time they are in a semi-dormant state and do not absorb nutrients. Fertilizer should only be applied when sunlight and temperature are suitable and photosynthesis is vigorous. In winter, orchids are in a dormant state, so there is even less need to fertilize. Before the new orchid shoots have grown to half maturity from the pseudobulbs, around the time the leaf buds emerge from the soil and during their elongation period, this is the vegetative growth stage of the orchid, and slightly more nitrogen fertilizer should be applied, with less phosphorus and potassium fertilizer. After vegetative growth comes reproductive growth. The nutrients produced by photosynthesis are stored in the pseudobulbs and leaves for flowering or new shoot growth. At this time, more phosphorus and potassium fertilizer is needed. Applying appropriate phosphorus and potassium fertilizer can promote plump and mature pseudobulbs, sprouting, and flowering. If orchid leaves are pale and yellow and the plant is weak, it is mostly caused by nutrient deficiency, and topdressing should be applied in time. But sometimes leaf yellowing is also caused by too strong sunlight. Diseased plants should not be fertilized; fertilize only after the disease has been cured and they have recovered. Robust orchid seedlings can be helped by applying more fertilizer.
Ancient orchid growers had experience:
"Never suddenly fertilize a thin orchid. Never keep a fat orchid thin for long." This means that a thin orchid that has never been fertilized cannot suddenly be given strong fertilizer, as it cannot absorb it and will be harmed. For orchids that are regularly fertilized, one also cannot go a long time without fertilizing. In short, uneven fat and thin conditions are not beneficial to orchids. Usually Cymbidium goeringii, Cymbidium faberi, and Cymbidium ensifolium begin fertilizing in early May. In the three fu periods of summer and from December to early February of the following year, do not fertilize. From May onward, apply light fertilizer once every 2-3 weeks until the end of September. In early September, apply light fertilizer once to Cymbidium goeringii, and in late September fertilize Cymbidium ensifolium once. After each fertilization, clear water must be added the next morning, which facilitates absorption by the orchid and also prevents root injury from improper concentration. Generally, do not fertilize around the flowering period.
(3) Fertilization methods.
Fertilization must mainly use organic fertilizer, which can make the soil loose with good structure and benefit orchid growth. Also, apply thin fertilizer frequently, that is, the previous generations' experience of "frequent and light, never sudden and heavy," which is the same meaning as today's "small amounts, many meals." When applying, dilute the water-fertilizer appropriately, then pour it into the root zone with a watering can, and do not pollute the orchid leaves. If chemical fertilizer is used, the concentration must be even lower. During the orchid growing season, a water solution of 2‰ urea and 2‰ potassium dihydrogen phosphate can be used as topdressing 2-3 times.
8. Ventilation.
Ventilation is also very important in orchid cultivation and management, yet it is often overlooked by people. 146 Zhuhong Xinsu (Beijing) With good ventilation and a constant supply of ample fresh air to the orchids, photosynthesis can be promoted, nutrient production increased, metabolism stimulated, and the orchids made to flourish. Ventilation in the orchid room and shade shed can regulate their temperature and humidity, making them favorable for orchid growth, and can also reduce the occurrence of pests and diseases. Orchid brown spot disease and southern blight mostly occur in poorly ventilated environments. The orchid growing site must be open, the terrain should be slightly elevated, the flower platform should not be too low, and attention should always be paid to ventilation. Orchids prefer gentle and mild breezes and dislike strong winds; excessively cold and strong winds should be avoided by all means. Orchid pots should be placed sparsely rather than densely, and sufficient distance should be kept between pots to prevent leaves from rubbing against each other in the wind and being damaged. If the site is small, the flower platform can be built into a terraced shape, which facilitates ventilation and also makes management and viewing easier. Each orchid pot should not contain too many or too densely planted plants. If the plants have multiplied too densely, they should be repotted and divided in a timely manner. Regularly remove weeds, diseased leaves, fallen tree leaves, and other debris from the orchid pots to facilitate ventilation within the pots. Daily work for ground-planted orchids throughout the four seasons: In spring around Qingming, remove the plastic film from the greenhouse, then water thoroughly once; several days later, apply once a 15-20 times diluted duck feather water or fertilizer water fermented from cake fertilizer. At the same time, spray once with 1‰ omethoate (containing 40% active ingredient) to kill insects. From May to July, apply once a month a fertilizer water made with 5% duck feather water or cake fertilizer. In August, apply once a 3‰-5‰ compound fertilizer. After the beginning of autumn, no more fertilizer is applied. Autumn management is extremely important, and we summarize it in two words: autumn hardening. That is, after the beginning of autumn, orchids are no longer fertilized, water is controlled, and light is increased to prompt early maturity. Generally, potted orchids should follow the golden rules of orchid care: do not take them out in spring, do not expose them to the sun in summer, do not let them dry out in autumn, and do not keep them wet in winter. But ground-planted orchids are not necessarily like this; in autumn, it is better to keep them dry than wet. The reason is: although the air is dry in autumn, ground moisture still rises in the soil, so there will not be severe water shortage; moreover, drought can temper the cold resistance of orchids and prepare them for overwintering. Autumn hardening can prompt nutrients to gather toward the pseudobulbs, increase the protoplasm concentration of the pseudobulbs, lower the freezing point, and prevent freezing injury. If orchid seedlings grow vigorously in autumn, then when a cold wave hits and the temperature drops sharply, they will inevitably suffer freezing injury. Ground-planted orchids cannot be moved indoors before the severe winter arrives, so only through autumn hardening can they survive. November is a relatively busy season in the orchid nursery, and the main work is to prepare the orchids for overwintering. First, remove the upper layer of shade netting, then install the plastic greenhouse; the two ends of the greenhouse should not be closed at first, and should be closed only when the temperature drops noticeably, and on clear days open them for ventilation at noon. This month, spray once with 1:1 Bordeaux mixture. When the severe winter season arrives, first, do not water easily; second, moderately increase light. By moderate, it means that in winter some clear days have relatively high temperatures. Especially with the warm winter phenomenon in recent years, at such times the lower layer of shade netting should be put down so that the temperature inside the shed does not rise or fall abruptly. If the shade netting is not put down and the temperature inside the shed reaches 18°C-22°C for several consecutive days, some new buds will begin to sprout, and once a cold wave arrives and the temperature drops sharply, they will undoubtedly be frostbitten. Therefore, in winter, a dormant environment must be created for orchids, and dormancy must not be easily broken. In early spring, cold and warm air masses move frequently over the land, so management must be even more careful; otherwise, orchid seedlings that have consumed nutrients over the winter are very likely to turn yellow and wither. Light should be gradually and moderately increased, and the plastic film should not be removed too early; only after the weather becomes steadily clear in early April can it be removed.
1. Potting soil requirements: It is best to use neutral to slightly acidic soil rich in humus, loose, and well-drained, with a pH generally around 5.5 to 6.5. In Sichuan, Emei Xiantu and "Xinghong brand" refined orchid growing medium are often used, and more commonly, "bamboo root mud" and leaf mold from moist forests in mountainous areas are used to cultivate orchids.
2. Placement site: Orchids can be cultivated outdoors and on balconies in spring, summer, and autumn, and a location with good ventilation, moist air, and no environmental pollution should be chosen. Being near ponds or riversides is of course good, but at least there should be trees or bamboo groves and shade netting to reduce sunlight exposure and lower the temperature. Orchid pots are best placed on wooden racks (or steel racks); if placed on the ground, bricks should be used underneath. On a home balcony, a small water trough made of galvanized iron sheet can also be used with bricks placed on top for cultivation, increasing humidity.
3. Proper shading: Most orchids belong to semi-shade plants, and most species are afraid of direct sunlight, so proper shading is needed. In early to mid-April, orchids can have the netting removed and windows opened, allowing more sunlight to promote growth. In May, aside from the midday sun, they can receive 6 hours of sunlight; starting in June, shade all day; after October, aside from the midday sun, they can be fully exposed for cultivation. Remember the proverb: "More shade makes good leaves, more sun makes good flowers."
4. Reasonable fertilizing: Orchids are inherently "vegetarian," and fertilizing should depend on the selected potting soil and growth conditions. Those growing luxuriantly and free of disease can be fertilized, while those growing poorly should not be fertilized or should be fertilized only lightly. Newly planted orchids whose roots have not fully developed should be fertilized only after 1-2 years. Generally, in June-July, when orchid leaf buds have extended to about 1.5 cm, apply a fully decomposed liquid fertilizer once every three weeks (the concentration should be on the dilute side, about 10%). Avoid chemical fertilizers. During high-temperature seasons, fertilizing is not advisable. In August-September, apply diluted liquid fertilizer once every two to three weeks. Each fertilizing of orchids should preferably be done in the evening, and in the morning water them with clear water, which is called "return water."
5. Proper watering: For watering orchids, rainwater and spring water are best; tap water or rice-washing water must be left overnight before use. When watering, pour from the edge of the pot, and do not pour into the flower buds. The amount of water should be determined according to temperature, the dryness or moisture of the potting soil, and the growth condition of the orchid plants. Plants with large leaves should be watered more; those with fine leaves, less. From April to May, when new buds have not yet emerged from the soil, the potting soil should be somewhat dry, as too much moisture makes new buds prone to rot; from June to September, during the new bud growth period of orchids, the amount of watering should be increased, watering once every morning on clear days, and absolutely avoid watering under the scorching midday sun. In autumn, reduce the amount of water appropriately, and foliar misting can be used to keep the potting soil moist; in winter, water should be controlled even more, maintaining the state of "eighty percent dry, twenty percent moist."
6. Mist in the evening: Orchids originally grow in moist air environments, so in dry seasons, in addition to shading, misting must also be done in the evening to increase air humidity and lower temperature; water can also be poured onto the ground (table surface) where the potted orchids are placed. "One cold and one hot" can further stimulate orchid growth.
7. Wind and rain protection: The yellowing and shedding of old leaves from the "February ghost wind" is a normal phenomenon, and dead branches and withered leaves can be cut off. Orchids can tolerate light rain, but must avoid moldy rain, heavy rain, or continuous rain, otherwise the heart and leaves are prone to rot. In seasons with a lot of rain, a small amount of plant ash can be scattered appropriately.
8. Pruning and flower removal: During orchid cultivation, withered, yellowed, broken, and diseased leaves should be cut off regularly to facilitate ventilation. For precious orchids, if there are too many flower buds, keep only the strong buds, with 1-2 flower buds per pot being appropriate. Spring orchids should have their flowers removed half a month after blooming, and precious orchids should have them removed after 7 days, so that the spring leaf buds grow robustly and produce better flowers the following year. For summer orchids, when the last flower on the inflorescence has been open for one week, cut it off 3 cm above the pot surface.
9. Cold protection and warmth: Because orchid varieties differ, their places of origin vary, and their cold resistance is also different, the time to move them indoors in winter and their indoor placement also differ. Cold orchids, autumn orchids, and New Year orchids grow in the south and should be moved indoors (or have windows closed and netting drawn around them) when the temperature is 5°C, and should be placed in a sunny spot facing south as much as possible. Spring and summer orchids have strong cold resistance and can be moved indoors only when the temperature reaches 0°C, and can be placed facing northeast. Around noon on clear, windless days, windows facing south or southeast should be opened and netting drawn for ventilation. Autumn orchids should not have windows opened on clear days at 1-2°C. Of course, if a greenhouse is available, electric lighting can be used for heating.
10. Disease and pest control: Potting soil generally needs to be sterilized (exposure to the scorching sun also works) to prevent disease. Orchids are most prone to southern blight in rainy, high-temperature seasons. For a small amount, it can be brushed off with a wet cloth; for many pots, 500-800 times Bordeaux mixture or thiophanate can be used, spraying once every 7-10 days. Among pests, scale insects (commonly known as "orchid lice") occur frequently. During the hatching period, use 1% omethoate and 25% phosmet emulsifiable concentrate at 1000 times dilution, spraying once a week. To treat the symptoms, one must treat the root cause; pots should be placed with appropriate spacing, arranged at different heights, and ventilation increased to reduce the occurrence of disease.
However, different orchids have different cultivation methods.
Several aspects needing attention in orchid cultivation
China has a long history of orchid cultivation, and our predecessors have accumulated rich experience in orchid growing for us. We should thoroughly understand the experience of our predecessors, absorb its essence, and deeply recognize that cultivation environment, growing medium, watering, fertilizing, and prevention and control of pests and diseases are the five major links in orchid cultivation and management.
1. The choice of environment is relatively important. Cymbidium faberi mainly grows under shrubs in subtropical mountain forests, developing the orchid's growth habit of preferring half shade and half sun and liking humidity and ventilation. As long as the growth patterns of orchids are grasped and environmental conditions close to those of orchids are provided or created, all parts of the country are suitable for cultivating Cymbidium goeringii and Cymbidium faberi.
2. Use of growing medium. According to cultivation experience in various places, as long as it is slightly acidic, no matter what growing medium is used (including soilless cultivation), orchids can be grown well; the issue is that different growing media should be managed with different methods. Flower pots are best made of clay pots or Yixing clay pots, because orchids are aerial-root plants and pot breathability is very beneficial to orchid growth.
3. Reasonable watering is the key to growing orchids well. The water used for watering orchids must be clean and slightly acidic, and water contaminated with pathogens must never be used. The watering method should differ according to the plant. Loose mountain soil contains sufficient water; granular soil plus stone and volcanic rock also absorbs water relatively fully, but does not accumulate water. After different growing media have been watered thoroughly once, when the pot surface is seen to be dry and about one centimeter of the growing medium has turned white, to increase air humidity, the pot surface can be sprayed to increase the moisture of the upper layer of the growing medium so that the orchid plants and pseudobulbs maintain a certain moisture; when the whole pot has not yet dried through from top to bottom, water heavily and thoroughly again.
4. Fertilizing: On the basis of mastering watering well, in order to promote better growth of orchid plants, fertilizing becomes even more important. Organic fertilizer, that is, farmyard manure, should be dilute and can be applied once every ten or more days; other inorganic fertilizers (chemical fertilizers) should be used according to the instructions. During the growing period of orchids, foliar fertilizer can be applied as a top dressing outside the roots. Base fertilizer is also very important. When repotting and changing soil, an appropriate amount of base fertilizer can be added as long as the fertilizer does not contact the orchid roots; too much fertilizer easily burns the orchid roots and causes black spots. If fertilizing is done properly, it can produce strong seedlings and good flowers. The general requirement for fertilizing orchids is a small amount, clear and dilute, truly achieving frequent application of light fertilizer.
5. Pest and disease control: Insect pests are easy to prevent, but fungal diseases are hard to cure. If scale insects and other pests are found on orchid plants, omethoate or decamethrin can be sprayed according to the instructions, preferably used in combination, 2-4 times per year. General fungal diseases such as black spot can also be treated with fungicides such as copper hydroxide, thiophanate-methyl, and chlorothalonil according to the instructions, with alternating treatment and preventive spraying at regular intervals of 15-20 days during the growing period. If Baras soft rot (rot coccus disease) is found, it is an incurable disease among orchids and cannot be cured at all; once discovered, remove it promptly. Therefore, when purchasing orchid plants, one must pay attention and never buy lower-priced diseased plants home, thereby affecting other precious orchids.
Different orchid species have different temperature requirements. For Chinese orchids, the most suitable temperature for vegetative growth is 20-30°C, the adaptive temperature range is 5-35°C, and the temperature for the reproductive period is generally between 5-15°C. Nighttime is 3-5°C lower than daytime. When the summer temperature is above 30°C, the higher the temperature, the more orchid growth is inhibited. However, under ventilated conditions, Chinese orchids are not harmed even by short periods of high temperature up to 35-42°C. When the temperature is below 12°C, growth is slow. When the temperature is below 12°C, Chinese orchids shift to reproductive growth. Cymbidium sinense originally grows in subtropical mountain forests. In summer, daytime temperatures can reach about 32°C, while at night it is cooler, with temperatures generally not exceeding 20°C, and winter temperatures do not drop below 10°C. Cymbidium kanran and Cymbidium ensifolium originally grow in transitional subtropical mountain forests. Cymbidium goeringii and Cymbidium faberi mostly grow in temperate mountain forests. In temperate regions, summer temperatures can reach about 38°C, but in shaded mountain forests, daytime temperatures do not exceed 30°C, and nighttime is around 18°C. In winter, under short-term snow cover, the surface temperature still exceeds 5°C, and flowering is not affected. Indoors, they can overwinter at around 0°C. The suitable growth temperature for Cymbidium tortisepalum is 18-28°C, not exceeding 35°C in summer, and not lower than minus 2°C in winter; the reproductive growth temperature is 8-18°C. For Cymbidium lianpan, the temperature requirement is generally not lower than -12°C in winter; in the reproductive period in spring and autumn, the temperature should not be lower than 12°C; in the summer growing period, the temperature is mostly suitable between 15°C-32°C, and above 35°C is the critical line for growth; beyond this limit, growth stops again.
The driving force of orchid life - light
"All things grow relying on the sun." This sentence highly summarizes the enormous role of light in the growth, development, and continuation of generations of organisms, especially plants. Orchid plants themselves rely on the photosynthesis of green leaves to obtain energy to maintain and continue life and reproduce; sunlight is the driving force of orchid life. But for orchids, which require a habit of half shade and half sun, excessively strong light is also harmful to orchid growth. It is necessary to regulate and control light suitable for orchids according to the temperature and humidity of different seasons and the growth habits formed under the ecological environments of various orchid plants, so as to satisfy and benefit the survival and growth of orchids. Below, regarding the close relationship between light and orchid plants, I will discuss some immature views and explore them somewhat with fellow orchid enthusiasts, which may be of some use for growing orchids well:
The following discussion is from five aspects:
1. The relationship between light and orchid plant growth.
2. The influence of light on orchid leaves, buds, and flowers:
3. The role of light in fertilizing and sterilizing orchid plants.
4. The light intensity for orchids.
5. Artificial regulation of light.
1. The relationship between light and orchid plant growth.
Suitable light can promote normal orchid growth: orchid growth relies on the photosynthesis of green leaves to obtain energy to maintain and continue life, and light's effect on photosynthesis in Cymbidium plants is accomplished through light quantity and light quality.
① "Light quantity." That is, light intensity. Plant photosynthesis changes with changes in light intensity, and photosynthetic intensity is directly proportional to light intensity. That is, when light intensity doubles or decreases by half, photosynthetic intensity also doubles or decreases by half. Through the chemical action of chlorophyll in orchid leaves, light absorbs carbon dioxide and releases oxygen to increase the nutrients needed by the orchid body. The bulbs and roots carry out digestion and decomposition at night, converting carbon dioxide into sugar, then forming various needed proteins, which are transported to all parts of the plant through the flow and pressure of water and air, so that potted orchids can grow shoots and bloom. Photosynthesis has heat limits and cold limits, that is, maximum temperature and minimum temperature, also called the critical points of photosynthesis. Too much and too strong sunlight, exceeding the critical point, can cause leaves to become dwarfed, yellowed, and even age prematurely without growing grass, gradually declining and dying. Conversely, if light is insufficient, although the plant still grows, the nutrients produced are not enough, which is likewise unfavorable to the healthy growth of orchids. Therefore, the levels of the plant's light compensation point and light saturation point directly affect the accumulation of organic matter and healthy growth of orchid plants. To make crops grow well, attention should be paid to lowering the light compensation point and raising the light saturation point. The usual measures are: sun plants should be reasonably densely planted, group development controlled, and the plants ensured sufficient light; if natural light is insufficient, artificial light should be added. Shade plants should be moderately shaded on the premise of satisfying their photosynthetic light intensity as much as possible. It is beneficial to let orchids have relatively abundant light of sufficient duration.
② "Light quality." The regulation of light should consider not only light quantity but also light quality. The intensity of plant photosynthesis varies with light quality. Sunlight contains seven kinds of visible light as well as invisible light such as ultraviolet rays. Orchid leaves respond only to red, orange, yellow, and blue-violet series of light. Different colors of sunlight produce differences in the intensity of plant photosynthesis; red light and blue-violet light are more efficient, while yellow-green light is lower. Not only does the intensity of photosynthesis differ, but the photosynthetic products are not entirely the same either. For example, when plants grow under blue-violet light, the amount of protein and fat in their photosynthetic products increases, while under red light more carbohydrates are formed. Infrared light irradiation is beneficial to plant cell division, showing as thickening in plants; far-infrared light irradiation is beneficial to plant cell elongation, showing as growing taller in plants; ultraviolet light irradiation is beneficial to shortening the nodes of orchids, showing as dwarfing in plants. Therefore, when supplementing light for orchids, different light qualities should be set according to the specific conditions and requirements of orchid seedling growth. (Ordinary incandescent lamps have less blue-violet light and more infrared light than the sun; fluorescent lamps have more blue-violet and green light and less red light; the visible light portion of xenon lamps is similar to sunlight, but ultraviolet and infrared light are greater than in sunlight.) Orchid cultivation generally uses more red light and blue-violet light. Experts suggest that supplemental lighting for Chinese orchid cultivation should use more red light. Of course, if conditions permit, choosing plant lights designed specifically for orchid supplemental lighting is even better.
In short, according to the types of photosynthetic products required as mentioned above, one should consider comprehensively, make up for deficiencies by drawing on strengths, and choose suitable light sources to promote the normal growth of orchids.
2. The influence of light on orchid leaves, buds, and flowers:
1. The influence of light on orchid leaves.
① Orchid leaves under different light: Orchids have long grown in mountain forests, developing a habit of half shade and half sun, preferring diffused light and disliking direct strong light. If light is too strong, orchid leaves tend to be shorter, thicker and stiffer, with a rough leaf surface, and the leaf color turns light green. If there is sudden strong light, the leaf color quickly turns yellow, the leaf surface becomes rough, and even the leaves become scorched. With moderate light, the leaves are green with fine texture and luster, and grow robustly. If light is too weak, the leaf color is emerald green, and the leaf texture is thin and long without luster. In short, the stronger the light, the yellower the leaf color; the weaker the light, the deeper the green. Too strong or too weak both affect the perfect growth of orchid plants.
② Changes in light can promote the manifestation of leaf variegation. Plants with the potential for variegation can receive a longer period of light, and for line-variegated orchids, sunlight from 6 a.m. to 9 a.m. is best. Someone did an experiment as follows: before 9 o'clock in summer and before 10 o'clock in winter, expose the orchid pot to sunlight, insert a thermometer into the pot, and when it reaches 30°C move it into the shade. When it drops to 25°C, move it out again into sunlight. Repeat this over a long period. One shade and one sun, one cold and one hot, is beneficial to the appearance of variable factors in the leaves, and over the years, variegated leaves may appear. However, this must be premised on the existence of recessive variegation factors in the orchid leaves; changes in sunlight merely promote their manifestation and are not necessarily connected. White-spotted cells are the decisive factor and play the decisive role in orchid line variegation changes.
2. The influence of light on sprouting. Light can increase the sprouting rate of orchid plants. Orchid sprouting cannot rely solely on water and fertilizer management; appropriately increasing light is very crucial. The sprouting rate under strong sunlight is generally high. Strengthening light can not only increase the sprouting rate but also make new buds stronger.
① Shallow planting of orchids produces more sprouts. Orchid growers generally believe that "deep planting is not as good as shallow planting" for orchid plants. This is because when orchids are planted deep, the bulbs are buried deep and receive less light; under the same fertilizer, water, and management conditions, deeply buried bulbs are small, and there are fewer sprouts in spring. With shallow planting (with half the bulb exposed outside the soil), the bulbs are large, and there are more sprouts in spring. This is closely related to the spectrum and the length of light time. It also demonstrates the reason why light can increase the sprouting rate of orchid plants.
② Light can promote flower bud differentiation and achieve the goal of more blooming. This is because light is the source of nutrients for flower bud differentiation and growth. The strength of light has a direct impact on the number of leaf buds and flower buds, the time they emerge from the soil, and their growth condition. Orchids with sufficient light produce more nutrients through photosynthesis, have more flower bud differentiation, bloom more, have deeper flower color, and have larger and better flower shapes. Conversely, orchids with too weak light may grow luxuriantly, but the nutrients produced are not enough, and they produce more leaf buds and fewer flower buds. Even if they bloom, the flower color is on the lighter side, the flower shape is poorer, and the growth is poor. Therefore, starting some time before flower bud formation, appropriately increasing light can promote flower bud differentiation and achieve the goal of more blooming.
3. The influence of light on flowering:
① The strength of light and changes in flower color. Sunlight is the fundamental source of color for all things in the world. The seven colors of the rainbow can change in countless ways, and the original colors of orchids are composed of ever-changing original light. Violet light and ultraviolet light in light are the main light energy forming orchid pigments. Therefore, sunlight has a direct influence on the colored flowers of orchids. Strong light makes flower color deeper and more vivid; excessively weak light makes flower color very pale. For example, to make the flower color of red-flowered lines beautiful, sunlight can be slightly strengthened; to make blue-colored lines produce beautiful flowers, sunlight should be reduced. Colored flowers should be properly shaded during the flowering season, because under sunlight red light and green light are not absorbed, while petal-shaped flowers should be on the sunny side to thicken the petals. When growing colored flowers, paying attention to and controlling light during cultivation can make the flower color more beautiful. Green and white flowers should receive reduced light; red, yellow, pink, and purple need increased light. For example, if Cymbidium goeringii blooms in shade, the flower quality and color are better than when it blooms in sun (except for colored flowers), and the flower stalk is also longer. For Cymbidium faberi and Cymbidium ensifolium, stronger light is beneficial to flowering, with larger flowers, better color, and fragrance. Therefore, controlling and regulating reasonable light is a maintenance technique that must be mastered to fully display the best flower color.
② The influence of light on orchid opening.
For orchid plants with flower buds, to promote early or delayed flowering, this can be achieved by regulating the length of light time. Appropriately extend light and increase temperature. For example, in a small room, using a 100-watt light bulb or infrared lamp to raise room temperature by 3°C-5°C can promote earlier flowering. Likewise, orchid plants with flower buds placed in a location with weak light and low temperature can also delay flowering. For orchid plants that have already formed flower buds, appropriately extending sunlight and raising temperature, or using a 100-watt light bulb or infrared lamp in a small room to raise room temperature by 3°C-5°C, can accelerate the flowering period and promote earlier flowering. Conversely, reducing light in a low-temperature environment can delay the flowering period, because raising or lowering temperature can accelerate or slow the physiological activities within the plant. Using this biological characteristic, some people have experimented: extending the light period to 14-16 hours can promote earlier flowering in medium plants and small seedlings; but for mature orchid plants, a light period of no more than 8 hours can promote flowering. Appropriately regulating light intensity can make orchids bloom at the right time, especially for species that bloom in spring, which generally have already formed flower buds from July to September of the previous year; after they pass through the hibernation stage, appropriately increasing light and raising temperature can make them bloom early in time for the Spring Festival holiday. Conversely, appropriately reducing light and lowering temperature can also delay flowering to coincide with orchid exhibitions. In short, regulating light intensity can make orchids bloom at the right time.
3. The role of light in fertilizing and sterilizing orchid plants.
1. The relationship between light and fertilizing. Generally, for various orchids in different seasons and at each growth stage, how to shade and supplement light so that orchids receive suitable light intensity is of concern to everyone. However, in the process of orchid cultivation, whether the relationship between fertilizing and light is correctly handled may not necessarily receive attention. In fact, this is equally very important for the vegetative growth of orchids. Strong or weak light will lead to strong or weak assimilation. If light is too weak, the assimilation of leaves is also insufficient. This leads to poor digestion of nitrogen fertilizer during the day, less accumulation of sugars and starch, and therefore less decline at night. Over time, leaves become very long while roots become very short. If light is too strong, the assimilation of leaves is also too strong. Orchid plant respiration increases, consuming excessive nitrogen fertilizer, causing leaves to become short, small, and yellowed. At the same time, abundant sugars and amino acids cause excessive growth of pseudobulbs and roots. The causes of these two poor growth conditions may be many-sided, and light is not the only factor (for example, long-term dryness of the orchid pot, too much stem fertilizer, high-carbon growth, small day-night temperature difference, nitrogen deficiency, and other conditions can also produce these problems). Failure to correctly handle the relationship between fertilizing and light is also one of the important reasons among them, and must be noted. The maintenance measures when encountering this situation are: when orchids show a state of "long leaves and short roots," light intensity must be gradually strengthened, organic nitrogen continuously supplied, and water supply reduced. After new roots grow out, they will slowly return to normal. When orchids show the phenomenon of "small leaves and strong roots," light should be reduced and sufficient inorganic nitrogen continuously supplied. This can both lower sugar content and promote protein synthesis, and the new grass produced can then return to normal.
Practice has proved that only under conditions of sufficient light can orchids absorb nutrients, so when fertilizing orchids there must be moderate sunlight. The best fertilizing time is the morning of good weather. When applying chemical fertilizer, the light intensity selected should be relatively higher; when applying organic fertilizer, it should be relatively lower.
2. Sunlight is a good weapon for sterilizing orchid plants and preventing disease. Light can not only increase temperature; ultraviolet light in the spectrum can kill and prevent the breeding of fungi, pathogens, and viruses, and pathogenic bacteria generally find it very difficult to survive under scorching sunlight. Therefore, exposure to the scorching sun can sterilize and disinfect pots and growing media. But for the sterilization and disinfection of orchid plants, the use of sunlight must be timed. For example, in winter, sun the orchids and let the whole orchid plant bathe in ample sunlight; in summer, avoid the scorching sun at noon and in the west. Light can also close the stomata of orchid leaves and block pathogenic fungi that easily invade through the stomata. We have found that orchid plants with good light exposure have strong disease resistance, while orchid plants with poor light, because their stomata are often open, are prone to infection by pathogen invasion. Orchid plants with insufficient light are prone to pests and diseases. Using sunlight for sterilization and disinfection has always been advocated by orchid growers. The photosynthesis of orchids, like other biochemical processes, cannot exist in isolation and is also constrained and influenced by external environmental conditions. These external factors are: light intensity, concentrations of carbon dioxide and oxygen, wind speed, temperature, water supply, inorganic nutrients, and pollutants in the atmosphere and soil, and so on. In addition, photosynthesis is also affected by the plant's own internal factors, such as chlorophyll content, degree of stomatal opening, and the physiological state and structure of the leaves themselves. By improving these internal and external factors mentioned above, the goal of improving plant photosynthetic efficiency can be achieved. This promotes healthy development, growth, and flowering of orchids. In summary, according to the growth habits of orchids, giving appropriate light can improve fertilizing efficiency, enhance disease resistance, and benefit the healthy growth of orchid plants. For this reason, for orchid plants that are weak, do not bloom, and are prone to pests and diseases, light must be strengthened.
4. The light intensity for orchids.
1. Orchids grow in mountain forest areas, and the ecological environment has developed their need for half-shade and half-sun light conditions. There is a folk flower proverb: "Shade for camellias, sun for peonies, half shade and half sun for four-season orchids." This shows that orchids have a half-shade and half-sun light habit, and the growth of all types of orchids cannot be separated from light. This is also a "common characteristic" of orchid plants.
2. The light requirements of various orchid plants are not entirely the same. Due to differences in ecological environments, various orchid plants differ in strong or weak light requirements. Generally speaking, Cymbidium faberi and Cymbidium ensifolium need more light for growth and can be shaded less. But in the vigorous growing summer and early autumn, strong direct light will still scorch some leaves, causing the leaves to turn brown, and even causing the leaves to become scorched and withered. At this time, shading is necessary, blocking 70%-80% of sunlight. Cymbidium kanran and Cymbidium sinense relatively need less light, and in summer 80%-85% of sunlight should be blocked. For newly potted grass, diseased and weak seedling grass, old grass, particularly delicate grass, and grass that has not been hardened and has long been under half shade and half sun, shading must be provided during the growing period. For edged grass, striped grass, crystal grass, if they are transparent bodies, etc., they cannot receive relatively strong direct light. Shading must be provided when sunlight is strong. The amount of shading is also a rough estimate, because different varieties under the same species do not have absolutely the same light requirements; for example, under the same species, variegated grass, colored flowers, and strong versus weak plants all differ in light requirements. This is the "individuality" of orchid plants. The cultivator needs to observe carefully in order to correctly grasp the appropriate light for various orchid plants.
3. Orchids can be roughly divided into three categories: sun-loving, semi-shade, and shade, as well as long-day and short-day, etc. Long-day orchids bloom as daytime gradually lengthens and nighttime gradually shortens; for example, Cymbidium ensifolium and summer Cymbidium kanran that bloom in late spring and summer; short-day orchids are the opposite, blooming as daytime gradually shortens and nighttime gradually lengthens, such as Cymbidium goeringii, Cymbidium tortisepalum, Cymbidium faberi, and Cymbidium sinense that bloom in late autumn and winter.
4. Reference values of optimal sunlight intensity for various orchids (unit: LUX)
Orchid species Sunlight range Optimal light intensity Light intensity for variegated grass
Four-season orchid 10000-14000 **** 10000
Cymbidium faberi 9000-13000 11000 9000
Cymbidium goeringii 8000-**** 10000 8000
Cymbidium tortisepalum 8000-**** 10000 8000
Cymbidium lianpan 8000-**** 10000 8000
Cymbidium kanran 8000-**** 10000 8000
Cymbidium sinense 4000-****5000 4000
"Fairburn and Pringle pointed out: no one can propose the best light quality and light quantity for orchid growth and development, because this involves complex factors, including light, temperature, different times, carbon dioxide concentration, length of sunshine, nutritional conditions, humidity, and the temperature difference between day and night, and so on." ---- Excerpted from Wu Yingxiang, "Chinese Orchids." Therefore, the sunlight intensity above is only a reference value.
5. The light intensity for orchid plants changes with the seasons: In winter and spring, orchids should see more sunlight and basically can go without shading. In summer and autumn, sunlight before 8-9 a.m. should be exposed to more, and the west-facing sunlight in the afternoon must be avoided, otherwise orchids are prone to disease. Sunlight and temperature have a great influence on orchid reproduction. If there is no sunlight for a long time in winter and the temperature is relatively low, it will affect the formation of winter buds, leading to few and poor-quality seedlings in spring and affecting the grass increase rate for the whole year.
6. Orchids like light in a cool environment. Generally, shading begins when spring passes and summer arrives, and ends only after late autumn. In summer, shade 40-50%; in late autumn, winter, and spring, full light exposure is suitable. Generally speaking: at 20-25°C, under direct sunlight, the chemical reaction between chlorophyll and light in orchid leaves is very fast, and the grass grows vigorously. Above 30°C, the chlorophyll in grass leaves automatically decreases, the leaf color becomes lighter, and a gray visible film gradually forms to reflect sunlight and prevent scorching. This condition can only be maintained for a relatively short time; when it lasts long, it starts from the tips of the orchid leaves and the whole plant gradually dies, especially old grass, which first turns yellow and then becomes scorched. Therefore, the length of time orchids receive light changes with high and low temperatures, in an inverse relationship.
7. Orchids like morning sunlight. When the morning sun first rises, the sunlight angle is low, and the orchid's illuminated area is large. Also, because morning sunlight is blocked by morning mist, the light is relatively soft, and direct exposure will not scorch orchid leaves. After nighttime nutrient accumulation, orchids have the strongest photosynthetic capacity in the morning.
5. Artificial regulation of light.
Light that is too strong or too weak is unfavorable to orchid growth, and orchid light varies greatly with differences in season, weather, region, environment, and so on. If light is therefore too strong, artificial shading must be adopted, the degree of shade adjusted well, and the light for orchids reduced. If light is therefore insufficient and affects the healthy growth of orchid plants, artificial lighting must also be adopted to supplement light moderately for orchid plants so that they have relatively abundant light of sufficient duration. In short, to give orchid plants appropriate light, it must be regulated artificially.
1. Bases for regulating orchid light:
① According to differences in light requirements among orchid species, regulate the appropriate light for various orchid plants. Different orchid varieties also differ in photosynthesis and optimum temperature. For example, different orchid species and variegation types differ at different times and in different regions. In the scorching days of midsummer and golden autumn, regarding shading requirements, the shade degree for Cymbidium ensifolium is 60%-70%; Cymbidium goeringii and Cymbidium faberi require 70%-80% shading in summer, while Cymbidium sinense needs about 80%-85%. Ordinary line-variegated orchids can be about 80%, while high-grade line-variegated orchids, crystal variegated orchids, and pattern-variegated orchids should be about 90%. Flower orchids and ordinary line-variegated orchids can receive full light before 9 a.m. and after 4 p.m. on clear days; high-grade line-variegated orchids, crystal variegated orchids, and pattern-variegated orchids should be half shaded. In high-temperature "furnace" areas, the shading density should be correspondingly increased by more than 5%. In winter and spring, appropriately increasing the light amount by 20% is more conducive to orchid growth.
② According to the light time and light intensity of different seasons, adjust the shade degree well. From late spring to summer and autumn, shade 40%-50%; in winter and early spring, 10%-20% light. Insufficient light will make orchid leaves soft and dark in color, and make the leaves at the rhizome area bend downward or outward. Especially during the leaf-drawing period, it makes the leaves grow rapidly. Conversely, too much light will make the leaves yellow or destroy chlorophyll and cause cell death, and too much light makes the leaves shorter and thicker and open or bend outward prematurely. Therefore, except in early winter and midsummer, move the orchids outside in the morning until 9-10 o'clock so that they receive sufficient light. As the angle at which sunlight strikes the earth shifts, light time, light intensity, and so on all change. In the short and weak light of winter and spring, except that high-grade line-variegated orchids, crystal variegated orchids, and pattern-variegated orchids need 60%-70% shading, all other orchids can receive full light, or be half shaded from 10-14 o'clock on clear days. In the long and strong light of summer and autumn, the shading time and density for orchid plants must also be adjusted accordingly.
③ According to weather changes. With ever-changing weather such as clear, partly cloudy, cloudy, overcast, and rainy or snowy days, light also changes frequently accordingly. Therefore, the shading degree must be appropriately adjusted according to weather changes and light strength. In particular, high-grade line-variegated orchids, crystal variegated orchids, and pattern-variegated orchids cannot tolerate strong light. If the shading degree is not adjusted in time, sunburn damage often results. In addition, if a fixed shading density is always maintained regardless of light strength, the sprouting rate and flowering rate of orchid plants will naturally not be as good as with timely adjustment.
④ According to changes in sunlight within a day, such as clear turning cloudy, cloudy turning clear, clear turning rainy, and clearing after rain, morning glow and evening sunlight can be allowed to shine, while the scorching midday sun must be blocked and regulated, and on cloudy days the shade degree should be reduced. It is worth noting that after summer heavy rain, or when it first clears after long rain, orchid pots must absolutely not be exposed to the scorching sun. Predecessors' experience: "If exposed to the sun immediately after rain, the water in the pot becomes hot, which scalds the leaves and injures the roots."
⑤ Regulate specifically according to differences in climate, light intensity, and so on in different regions. China has a vast territory, and cold and hot climates and light intensity differ, with relatively large differences. However, the standards and requirements for strong, weak, and moderate light for orchid growth are still unified, and specific regulation can be carried out according to the local climate.
⑥ Regulate according to high and low temperatures. Orchid photosynthesis is closely related to temperature. Generally speaking, Chinese orchids carry out normal photosynthesis at 5-36°C, with the optimum temperature being 18-28°C. When the temperature is as low as 0°C and as high as 40°C, these are the limits, and orchid photosynthesis is inhibited. Starting from the low limit, photosynthesis strengthens as temperature rises. Beyond the optimum point, photosynthesis declines; above 36°C photosynthesis is very weak, and when it reaches the 40°C limit, photosynthesis also stops. When the temperature is high, use shading to cool down; when the temperature is low, heating equipment can be used to raise the temperature, thereby achieving a relatively suitable temperature, promoting orchid photosynthesis, and ensuring the health and rapid growth of orchids.
⑦ According to the phototropism of orchid plants. Orchids have phototropism, and the direction of the orchid pot should be rotated and adjusted at intervals, so as to prevent the plant leaves from leaning to one side. In particular, the side with new plants should face the direction with sufficient light during the budding period, so as to facilitate sprouting and healthy growth of buds. If for the special needs of shaping or composition, in order to express a specific poetic and artistic conception, the position of the light source can also be used to strengthen the tendency of flowers and leaves, achieving the beauty of dynamic balance and satisfying appreciation needs.
⑧ Regulate according to the growth condition of orchid plants. Generally speaking, if the leaf color is light green, and orchid leaves are thin, weak, and leggy, then light is too strong; if they appear yellow-white or even scorched and withered, it indicates that light has exceeded the orchid plant's tolerance. Conversely, if the color is dark green or deep green without luster, it indicates that light is too weak. Regulate shading well according to the growth condition of orchid plants. In addition, if stems and leaves are relatively dense and soft, with many leaf buds and few flower buds, then light is insufficient; conversely, if stems and leaves are sparse and firm, with few leaf buds and many flower buds, then light is too strong. Both are abnormal and need timely adjustment.
⑨ Regulate light according to the growth period of orchids. During the growing period, the supplemental light time should be longer; during the dormant period of orchids, a little less.
⑩ According to professional testing. (Excerpt)
(1) The light intensity for well-growing orchids is 4000-5000 Lux (lux, unit of light intensity), and their sprouting rate, flowering rate, leaves, and leaf color are all excellent.
(2) From the practice of professional testing, it has been found that orchids have a saturation point for light requirements. After light reaches the saturation point, even better sunlight is also harmful and of no benefit to orchids.
(3) Plants most easily absorb red and blue light, and a balanced combination of red and blue light is especially important for photosynthesis. According to experiments, red light can promote orchid growth, while blue light is indispensable for thickening leaves, accelerating plant development, and regulating stomatal opening. Green light also cannot be ignored; it can promote oxygen production, thereby helping orchids better accumulate nutrients.
(4) A certain intensity of long-wave ultraviolet light is also indispensable; it can help form anthocyanins and inhibit the elongation of branches and leaves.
2. Methods for regulating orchid light:
First, shading. In nature, orchids mostly grow in shaded mountain forest environments with scattered sunlight, and semi-shade and shade types account for more than four-fifths of all orchid plants. Therefore, when light is too strong, shading must be used to weaken the light.
(1) Plant shading. Imitating the natural environment, using plants for shading is one of the relatively ideal methods. The method is: on the orchid cultivation site, set up bamboo frames, wooden frames, or reinforced concrete frames, and let grapevines, honeysuckle, morning glory, Chinese trumpet creeper, cypress vine, and other climbing plants spread over them, which can both shade and be beautiful. Deciduous climbing plants shade in summer and let light through in winter, which is a kind of natural regulation. Trees can also be planted around the orchid nursery, selecting evergreen trees of different heights, deciduous trees, bamboos, and so on, planted in combination to regulate light intensity.
(2) Shade with shade netting. A shade frame can be built from bamboo, wood, angle steel, etc., covered with bamboo blinds, plastic film, shade netting, etc. On top of it, install a double layer of shade netting with a 50%-70% shading rate; the upper layer is relatively fixed and only rolled up in winter, while the lower layer can be put on or rolled up. In midsummer use the double layer, in spring and autumn use a single layer; on sunny middays in summer and autumn use the double layer, on cloudy and rainy days use a single layer. In winter, decide according to conditions: on sunny days let down the lower layer, on cloudy days roll up the lower layer. In addition, before the orchid flower buds are about to open, they must have moderate diffused sunlight, otherwise the flower color will be dull and will not show its beauty. It is best to install the shade netting in a movable style so that the shading density can be increased or decreased as needed. The shade netting should as far as possible not be pressed tightly against the plastic film or glass on the top of the shed, and there should also be a gap of about 30 cm between the net layers. The shade netting should be set outside the plastic film or glass, for only then will the shading effect be good. If it is set inside the shed, its shading effect will be greatly reduced. When growing orchids on a balcony, at noon when direct sunlight shines the light is intense, and the walls have reflected light and radiant heat, and ventilation is also poorer than in a courtyard or orchid nursery, so in hot seasons, outside the anti-theft grille, for 3-4 hours around noon, hang a 50% shade net to prevent scorching the orchid plants; when the sunlight slants and the temperature has also dropped, roll it up promptly to facilitate ventilation and air movement. Orchid shading requires a certain regularity. Generally speaking: large-leaved types require more than small-leaved types, and low-altitude types require more than high-altitude types. In summer more shading is needed, in winter less shading can be used; at noon more shading is needed, in the morning and evening less shading can be used; in high temperatures more shading is needed, in cool weather less shading can be used, and so on.
Second, "supplementary lighting." Regulating light in an orchid-growing site is not only about shading; when natural light is insufficient, artificial lighting also needs to be added to appropriately supplement light for the orchid plants, especially for indoor orchid growing and after the beginning of winter when the light duration is short, which has a certain effect on orchid growth. Only by supplementing light to meet the orchid's light requirements can the orchid plants develop soundly, with sturdy stems, and grow and bloom.
(1) Basis for supplementary lighting. How to supplement light appropriately, and what kind of light to supplement? There must be a scientific basis. Sunlight is a collection of continuous wavebands of light from red to violet, and artificial simulation of the plant growth environment should also start from this. In artificial supplementary lighting, besides considering the light quality and light intensity necessary for orchid growth, the physiological radiation characteristics of the light source also need to be considered. (Light waves matching the characteristic curve of plant chlorophyll synthesis are called physiological radiation light sources, that is, photosynthesis light waves.) Under different light qualities, not only is the intensity of photosynthesis different, but the photosynthetic products are also not completely the same. For example: plants absorb red light most strongly, with blue light next; when plants grow under blue-violet light, the amount of protein and fat in their photosynthetic products increases, which is effective for thickening stems and leaves, accelerating plant development, and regulating stomatal opening. Under red light, more carbohydrates are formed, which can promote orchid growth. Violet light and ultraviolet light mainly form anthocyanins and inhibit the elongation of branches and leaves (ultraviolet light must not be too strong, or it will scorch orchid leaves). Green light also cannot be ignored; it can promote oxygen growth, thereby helping orchids better accumulate nutrients. In addition, a certain intensity of long-wave ultraviolet light is also indispensable; it can help form anthocyanins and inhibit the elongation of branches and leaves. Supplementary lighting must be based on the effects of the above spectrum and the growth condition of the orchids in order to choose a suitable light source.
(2) Light source selection. Because light quality has an obvious effect on the composition of photosynthetic products, people should choose suitable light sources according to the type of photosynthetic products needed. Ordinary incandescent lamps have less blue-violet light than the sun and more infrared light; fluorescent lamps have more blue-violet and green light and less red light; generally speaking, orchid cultivation can use a mixed light of red, blue and white tubes to supplement the insufficiency of light. A complete combination of red and blue spectra can enable orchids to achieve optimal growth. Philips' tri-phosphor 6400K fluorescent lamp can basically meet the growth requirements of orchids, and the price is also cheap. Of course, if conditions permit, it is best to choose plant lamps specially designed for orchid supplementary lighting; they are a bit more expensive, but the effect is better. Using LED lighting, the plant growth rate and photosynthetic rate both increase by more than 20%. Compared with ordinary lamps, LED lamps have especially strong durability and save electricity, reducing operating costs. When choosing a light source, one should consider not only light quality and light quantity, but also low power consumption, economy, durability and ease of use.
(3) Supplementary lighting duration. After installing artificial lighting equipment in the orchid room, the supplementary lighting duration should be determined according to the actual light conditions of the orchid-growing site, the seasonal changes in light, weather changes and the orchid's growth period. According to the different growth periods of orchids and the orchid-growing environment, the supplementary lighting duration also differs somewhat. For indoor orchid growing where the light is not strong but diffused sunlight can enter, there should be no less than 5 hours of supplementary lighting; on a balcony there should be no less than 4 hours of artificial supplementary lighting; in a basement or an indoor space that does not see sunlight, there should be no less than 10 hours of artificial supplementary lighting. During the orchid growth period, the supplementary lighting duration should be longer, and during the dormant period it should be shorter; on cloudy, rainy and foggy days there should be no less than about 10 hours of artificial supplementary lighting. The supplementary lighting duration involves many factors and needs to be tested in practice to obtain a relatively correct supplementary lighting duration.
(4) Lighting distance. Light intensity is inversely proportional to the distance from the light source to the leaf surface, that is, the closer the distance, the stronger the light intensity, so the height distance of the light tubes can be adjusted to regulate light intensity, so as to meet the appropriate light requirements of different orchid species. How to choose the lighting distance: the installation distance of the supplementary light should be set according to the power of the lamp and the height of the orchids. The closer the lamp is to the orchids, the higher the light utilization, but care should be taken to avoid the lamp being too close to the orchids and the temperature being too high, which would cause harm to the orchids. Fluorescent lamps and special plant light sources (40W) should be at a distance of 20-40 cm; incandescent lamps (100W) should be installed at a certain height from the plants, because the large amount of infrared radiation from incandescent lamps will be converted into heat energy, so 70 cm or more is better; for high-pressure sodium lamps (120W-400W), keeping a vertical distance of 1 m-1.5 m from the plants is more suitable. For LED supplementary light sources, because LEDs produce very little heat energy, they can illuminate at close range, and 10 cm is better.
(5) Light direction. To ensure the supplementary lighting intensity for orchids, the lamps should as far as possible be arranged directly above the orchids. Benefits: first, due to the phototropism of plants, with more overhead light, the leaves of the orchids grown tend to be more upright, which conforms to the aesthetic requirements of orchid lovers; second, if the angle of the light is consistent with the growth angle of the plant stems and leaves, the light intensity received per unit area is higher, which helps improve light energy use efficiency.
(6) Precautions for supplementary lighting.
1. It is best not to supplement light at night, because orchid growth requires a certain period of darkness to regulate the respiratory function within the orchid plant and to carry out the transformation and synthesis of dry matter in the plant.
2. Pay attention to ventilation. Most supplementary lights generate heat energy, especially in summer, which can raise the temperature of the orchid room or orchid shed and cause orchid diseases. Ventilation can reduce the heat.
3. Comprehensive configuration of light sources. To obtain a better supplementary lighting effect, light fixtures of different light sources need to be comprehensively configured, such as a combined configuration of fluorescent lamps and incandescent lamps, or a combination of low-pressure sodium lamps and incandescent lamps. This meets the orchid's needs for various spectra during growth.
4. Pay attention to the installation safety of supplementary lighting fixtures to prevent accidents.
The above briefly describes the role of artificial supplementary lighting for orchids and some specific issues. In short, by appropriately supplementing light for orchids and ensuring that orchids have relatively sufficient light, not only can the cold resistance of orchids during winter be improved, but the vigorous growth and abundant flowering of orchids in the coming year can also be ensured.
Third, "hardening the plants." Orchids have a relatively strong adaptability to light, and this is also related to the generation count of the light intensity received. They will gradually change and adapt. For orchids that have always been grown in shade, if the plant's light conditions are artificially changed, after a period of time the structure and function of their chloroplasts will undergo a certain degree of change to adapt to the new light conditions. For example, under weaker light conditions, the structure and function of plant leaves will develop in a shade-tolerant direction, enabling them to maintain relatively high photosynthetic efficiency under weaker light; conversely, under stronger light conditions, plants can also adapt to a certain extent and effectively use ample sunlight for photosynthesis. The folk term "hardening the plants" roughly means this - letting orchids adapt to different environments - including light, temperature, and so on. Through "hardening the plants," they can be cultivated to become stronger generation by generation.
Fourth, display. In the display of potted orchids, according to the habits of each type of orchid, those with high light requirements should be displayed in places that receive the most light. Those with low light requirements should be displayed in positions with less light. In addition, orchids have phototropism, so it is best to adjust the pot orientation once or twice a month to avoid the plant's leaves leaning to one side. In particular, the side that has new growths should face the direction with sufficient light during the budding period, so as to facilitate sprouting and the healthy growth of the buds.
In summary, light plays a vital role in the growth, development, flowering and reproduction of orchid plants. Although orchid plants prefer shade, if all things in heaven and earth had no sunlight, they could not carry out photosynthesis to make nutrients. Nor could they survive. Therefore, light is the driving force of orchid life. Photosynthesis is also a quite complex issue. Orchid photosynthesis, like other biochemical processes, cannot exist in isolation, and at the same time is restricted and affected by external environmental conditions. These external factors are: light intensity, concentrations of carbon dioxide and oxygen, wind speed, temperature, water supply, inorganic nutrients, and polluting substances in the atmosphere and soil, and so on. At the same time, light is also affected by factors internal to the plant itself: for example, different orchid family plants have certain differences in light duration, intensity and requirements. Another example is the influence of chlorophyll content, degree of stomatal opening, and the physiological state and structure of the leaves themselves. Only by improving the above internal and external factors can the goal of increasing plant photosynthetic efficiency be achieved, promoting healthy development, growth and flowering of orchids.