What should you do when orchid leaves turn yellow? Add light, water and fertilize sensibly, and leave normal yellowing leaves alone
As one of the Four Gentlemen of Flowers, the orchid (that is, the orchid) has undeniable beauty: its leaves are elegant and its flowers are lovely, making it deeply loved by flower enthusiasts. But during cultivation, many growers find their orchid leaves gradually turning yellow, which seriously affects the plant's ornamental value. So what should you do when orchid leaves turn yellow
As one of the Four Gentlemen of Flowers, the orchid (that is, the orchid) has undeniable beauty: its leaves are elegant and its flowers are lovely, making it deeply loved by flower enthusiasts. But during cultivation, many growers find their orchid leaves gradually turning yellow, which seriously affects the plant's ornamental value. So what should you do when orchid leaves turn yellow? Today the editor will solve this problem for you.
I. What to do when orchid leaves turn yellow
When it comes to yellowing orchid leaves, it is usually caused by improper care: if you have watered too little, replenish water in time; if you have watered too much, loosen the soil more, and in serious cases take the plant out of the pot, cut off the rotted roots and replant; if it is caused by too strong light, shade it; of course, if it is caused by natural metabolism, no special treatment is needed, and it will recover on its own.
II. Causes of yellowing orchid leaves and solutions
1. Unsuitable environment
If a newly bought orchid shows yellow leaves, you should consider that it is caused by an unsuitable environment. It is understood that nowadays most potted orchids bought by flower enthusiasts are purchased online, which easily leads to large regional differences and big environmental changes, so the plant cannot adapt for a while and its leaves turn yellow.
Solution: When the leaves of a newly bought potted plant turn yellow, you should provide the environment most suitable for its growth according to the orchid's growth habits, and before long the plant will return to health.
2. Too much light
During cultivation, orchids need light, but they prefer diffused light and fear strong light. Once exposed to strong sun, their leaves will be scorched and turn yellow.
Solution: Move the orchid promptly to a ventilated, shady place, and after it recovers, water it appropriately, then gradually increase the light. For this, the editor recommends placing the orchid on a balcony fitted with a shade net: shade it when the light is strong, and do not shade it when the light is weak.
3. Improper watering
① Insufficient watering: Orchids like a humid environment, and daily care requires keeping the potting soil slightly moist. Once watered too little, the plant's leaves will turn yellow due to lack of water. Solution: Water the orchid appropriately, and afterward water it in time once the potting soil dries out.
② Overwatering: Although orchids like water, they hate waterlogging. Once watered too much, causing water to accumulate in the potting soil, their roots cannot breathe properly and the leaves cannot absorb nutrients, so they naturally turn yellow. Solution: Loosen the soil in time and air-dry the soil; if you did not notice in time and the roots have already rotted, you need to take the plant out of the pot, cut off the rotted roots, then change the potting soil and replant.
4. Insufficient fertilization
Having covered watering, let us talk about fertilizing, which is also one of the causes of yellowing orchid leaves. Orchids like fertilizer, and sufficient nutrients let them grow better; conversely, once fertilized too little, the plant will suffer from malnutrition, causing the leaves to turn yellow.
Solution: Although the probability of yellow leaves due to lack of fertilizer is very small, to avoid this phenomenon you should add some organic fertilizer in appropriate amounts.
5. Natural leaf yellowing
If the above points can be ruled out, then yellowing orchid leaves may also be normal. It is understood that older orchids usually have some old leaves, which will naturally turn yellow and fall off.
Solution: This situation is completely normal, so you do not need to do anything; just let them fall off slowly.
Overall, the cultivation method for orchids is not difficult, but not difficult does not mean they can be grown casually. To keep their leaves evergreen and not yellowing, you must pay attention to light, water and fertilizer. Of course, do not panic when you find yellow leaves; just solve it according to the methods above. That is all the editor has to introduce about yellowing orchid leaves, and I hope it can help everyone.
A complete guide to orchid cultivation and growing techniques
"Three parts planting, seven parts care" - this is the ancients' experience in growing orchids. The quality of care determines whether orchids thrive and whether they can bloom, so the predecessors' great attention to this made sense. Below is a detailed introduction to the methods of caring for and managing orchids.I. Location
The place where orchids are placed is very important, as it directly affects the orchids' growth and development. Orchids are generally placed outdoors in spring, summer and autumn (in a shaded spot outdoors in summer), and indoors in winter. Outdoors, it is best to have open space all around and humid air. Indoors, there should be plenty of light, preferably facing south. This is favorable for orchid growth. The orchid pot is best placed on a wooden stand or table, not on the ground.
II. Shading
Most orchids belong to semi-shade plants, and most species fear direct sunlight and need appropriate shading. In early to mid-April, orchids can be given more sunlight to promote growth. After late April, they should be appropriately shaded. Among summer orchids and autumn orchids, varieties with upright leaves are best placed on the south side of a shaded spot so they receive a suitable amount of extra sunlight; for autumn orchids and spring orchids with drooping leaves, two hours of light per day is best. From the beginning of June to September, shade earlier each day; for example, with reed blinds you can use dense blinds or two layers of sparse blinds. After October the weather turns cooler and the sunlight is weaker, so shading can be delayed, but around noon you still need to pay attention to shading work.
III. Rain protection
Orchids can take light rain, but must be protected from 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 is short and the amount is small, water more in the evening to let the hot air out of the pot; otherwise the orchids will be damaged, or even have rotted roots and die. If the sun comes out right after a shower, shade them in time to prevent the hot air rising from the ground from affecting orchid growth. The rainy season coincides with the stage when orchids sprout leaf buds; if the potting soil is too warm, it will cause poor leaf bud growth or invite disease. At this time, you can scatter a small amount of plant ash to regulate the moisture of the potting soil.
IV. Watering
A flower proverb says: "Dry orchids, wet chrysanthemums," and there is some truth to this. Generally speaking, orchids do best at eight parts dry and two parts wet. If too wet, the flowers easily rot at the roots and die. The principle of watering should be: water when dry, stop when wet, and lean appropriately toward dry. In practice, generally note: during the growing period (late May to late June) water appropriately more; during the leaf bud sprouting period (about March to April) and the flowering period (about March to April) water appropriately less; during the dormant period (winter), water even less or not at all. If the pot is large and the orchid plant is small, water less; if the pot is small and the plant is large, water more. In hot, dry weather water appropriately more; in cold, damp 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 potting soil a bit dry, so the roots will not rot and new leaves can sprout better. The ancients' experience that "do not dry in autumn, do not wet in winter" is a very good summary of how to water spring orchids and summer orchids. But in some northern regions, because the climate in winter and early spring is too dry, you should not let the orchids become too dry either. Watering time: in summer and autumn, water after sunset so the orchid leaves dry before nightfall, or you can water in the early morning; in winter and spring, watering around sunrise is best. Do not pour cold water suddenly after scorching sun, lest the soil temperature drop, affecting root water uptake and disturbing physiological balance. The amount of water must not be too large, to help suppress disease occurrence.
Watering method: Water from the edge of the pot; do not pour into the flower buds, to avoid causing rot.
The predecessors had very good summarized experience on watering orchids. For example, in "Records of Orchid Growing in the Capital" Yu Zhao proposed different watering methods according to the twenty-four solar terms within a year. The following is an excerpt for reference. But note two points: first, "Records of Orchid Growing in the Capital" uses Beijing's climate as the standard; second, the months in the text refer to the lunar calendar rather than the Gregorian calendar, so "the first month" is actually February in the Gregorian calendar.
1. Start of Spring, Rain Water: spring orchids have already set flowers, the soil should not be too dry; moisten slightly 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 half dry (empty above, solid below), you may moisten it, but not too much; autumn orchids same as before.
3. Spring Equinox: spring orchids have finished flowering and hate moisture; when the pot is half dry, you may moisten it.
4. Clear and Bright, Grain Rain: do not let the potting soil become too dry; moisten with water every 5 days.
5. Start of Summer: orchids begin to come out of the room; water thoroughly once.
6. Grain Full: do not let the potting soil become too dry or too wet. If spots appear on the leaves, it is too wet; if the tips of new shoots wither, it is too dry. Water 1 sheng (about a dry teacup) every 4 days, so that the lower 2/3 of the potting soil from the bottom up is moist.
7. Grain in Ear: the climate is dry, so pay even more attention not to let it become too dry or too wet.
8. Summer Solstice: the potting soil must not be too dry; if there is heavy rain, it can only endure one day; if there are successive days of overcast rain, move the pot to a ventilated place.
9. Minor Heat: at this time the air is too humid, and the potting 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, you must wait until the potting soil has dried to 2/3, otherwise do not water again.
10. Major Heat: the potting soil easily dries all the way through; note that each day only one heavy rain or one heavy wetting is appropriate.
11. Start of Autumn: orchids just need water at this time; water 2 sheng every 3 days, and they should also be given wind protection.
12. End of Heat: water once every 5 days; except during successive days of hazy rain, they may be allowed to receive rain and dew.
13. White Dew: autumn orchids need frequent watering even more than spring orchids, but after being wet they must dry out greatly before they can be wet again.
14. Autumn Equinox: if autumn orchids have already produced flowers, water slightly less; if they have not produced flowers, water slightly more.
15. Cold Dew: autumn orchids should be watered thoroughly; spring orchids should not be watered thoroughly but only moistened.
16. Frost's Descent: orchids should be brought indoors; watering time changes to midday, and after watering they need to be placed in the midday sun for 1-2 hours.
17. Start of Winter: only moisten with water, about half a sheng every 5 days.
18. Minor Snow: the flower room must not be warm, and it should not be too humid; if too damp it can cause root rot, leaf scars and even withering. If the pot has not dried to the bottom, only slightly moisten the surface of the soil.
19. Major Snow: autumn orchids do not need water; spring orchids should be slightly moistened
20. Winter Solstice: do not irrigate either.
21. Minor Cold: avoid watering either.
22. Major Cold: autumn orchids still do not need water; spring orchids may be slightly moistened with water.
V. Fertilizing
Whether to fertilize orchids should be decided by their growth condition. Those growing luxuriantly and free of disease can be fertilized; those growing poorly should not be fertilized or only lightly fertilized. Orchids newly dug from the mountains must absolutely not be fertilized before new roots have developed; they need 1-2 years of cultivation, and only when the new roots are vigorous can they be fertilized, otherwise they easily wither and die.
Generally speaking, in June-July, when orchid leaf buds have extended about 1.5 cm, you may apply 1-2 times a dilute, well-rotted liquid fertilizer (do not use chemical fertilizer), but do not fertilize in high-temperature seasons. In August-September, apply 1-2 more times of rotted dilute liquid fertilizer. For orchid varieties of the plain-heart type, applying 1-2 times of plant ash infusion works very well. Fertilizing in the evening is best, and the next morning water once with clear water.
A relatively simple way to tell whether orchids need fertilizing is to look at the depth of leaf color. Leaves that are yellow and thin indicate lack of fertilizer and should be top-dressed; leaves that are dark with scorched tips indicate too much fertilizer, and fertilizing should stop.
For fertilizer, you can use the various methods introduced above to make your own. 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 plant's root zone, and absolutely do not apply it to the leaf surface. Main fertilizing times and dates for orchids: times, dates, category, first time, second time, third time, fourth time, remarks
Spring orchid type: late June, mid-July, mid-August, early September; the fourth time must be especially dilute
Summer orchid type: late June, mid-July, mid-August, early September; the fourth time must be especially dilute
Autumn orchid type: early June, late June, late July, mid-August; the fourth time must be especially dilute
VI. Pruning
During orchid cultivation, pruning must be carried out continuously. When old leaves wither and turn yellow, they should be cut off in time to improve ventilation; some leaves whose tips have dried out should also be cut off. In particular, leaves harmed by pests and diseases must be removed in time to avoid contagion. When cutting off leaves with viral disease, the scissors used should not then be used to cut healthy leaves, to prevent virus transmission. If the same pair of scissors is used, it must be disinfected. After the flower buds of precious orchids emerge from the soil, if there are too many flower buds, keep the strong buds and remove the rest of the thin, small flower buds; 1-2 flower buds per pot is appropriate. If there are too many flower buds, it will not only make that year's flowers bloom poorly, but also consume too much of the mother plant's nutrients and affect next year's flowering. Generally, orchids do not need their flower buds cut off. Spring orchid flowers, after about half a month of blooming, 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 so the fruit becomes plump and ripe.
VII. Cold protection
Autumn orchids should be protected from the cold early; for example, when the temperature is 2-3°C, they can be moved indoors. Cold orchids grown in the south need even earlier cold protection. Spring and summer orchids have stronger cold resistance, but if freezing occurs they must also be moved indoors in time. If the room temperature can be kept at 1-2°C, they can overwinter. If a severe cold wave hits and the room temperature drops below zero, heating must be provided 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 facing south and southeast should be opened for ventilation (autumn orchids must not have windows opened on overcast days at 1-2°C, to prevent cold wind from blowing in and freezing the leaves). Autumn orchids like to be drier in winter, while the potting soil of other orchids should be kept moist.
VIII. Flower removal
For orchids growing poorly, with few leaves per clump or poor roots, the flowers should be removed. For better varieties, spring orchids can appropriately have 1-2 flower buds removed; for summer orchids, when the flower buds have extended, keep 1-2 flower buds and remove the rest, so the flowers can last longer, more new leaves can sprout, and old leaves are less likely to wither and die. Precious spring orchids should have their flowers removed after 3-5 days of blooming, so the leaf buds grow vigorously; for summer orchids, when the topmost flower has opened, they can also be cut off at a point several cm above the pot surface.
IX. Flood prevention
If the cultivation site is open all around and the terrain is relatively high, when strong winds or a typhoon passes through in summer, wind protection work must be done well to prevent the leaves of summer orchids or cold orchids from being broken and damaged.
X. Misting
In dry seasons, mist every evening on the balcony where the potted flowers are placed, mainly to make the ground moist and increase air humidity. The surface of the orchid pot should also be misted. When misting, spray upward so the mist droplets fall finely and evenly and the leaf surface becomes moist; this can promote good orchid growth and give the leaves a glossy appearance.
XII. Pest and disease control
Sterilization treatment should be carried out (exposing to the scorching sun is enough) to prevent disease. Orchids are most prone to southern blight in rainy, high-temperature seasons; it can be prevented by spraying with 800 times Topsin solution or Bordeaux mixture. If the disease is severe, you can use Topsin diluted 500-750 times, spraying once every 7-10 days. Among insect pests, scale insects occur the most; this insect attaches to the base of the leaves, and if scale insects are found, they should be removed in time. To avoid scale insect infestation, starting in April you can use "1059" at 2000 times solution for control. In order to suppress the occurrence of orchid diseases, besides appropriately controlling the dryness and wetness of the potting soil at ordinary times, you should also choose clay pots as much as possible for the flower pots and use fewer glazed pots. In particular, newly dug orchids from the mountains that grow poorly must be planted in clay pots. Doing so makes the potting 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 containing a large amount of humus, loose and well-drained, is best, 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 soil" and leaf mold from broad-leaved forests in mountainous areas are used to cultivate orchids.
2. Placement site: Orchids can be grown outdoors and on balconies in spring, summer and autumn, and you should choose a place with good ventilation, humid air and no environmental pollution. Being near a pond or riverside is of course good; at the very least there should be tall trees or bamboo groves and a shade net to reduce sunlight exposure and lower the temperature. The orchid pot is best placed on a wooden stand (or steel stand); if placed on the ground, put bricks underneath. A home balcony can also use a small galvanized iron sheet water trough to store water with bricks placed on top for cultivation, increasing humidity.
3. Appropriate shading: Most orchids belong to semi-shade plants, and most species fear direct sunlight and need appropriate shading. In early to mid-April, orchids can have the net removed and windows opened, giving more sunlight to promote growth. In May, apart from the midday sun, they can receive 6 hours of light; from the beginning of June, shade all day; after October, apart from midday, they can be fully exposed for care. Remember the proverb: "More shade, better leaves; more sun, better flowers."
4. Reasonable fertilization: Orchids are naturally "vegetarian," and fertilizing should depend on the chosen potting soil and growth condition. Those growing luxuriantly and free of disease can be fertilized; those growing poorly should not be fertilized or only lightly fertilized. Newly planted orchids whose roots have not fully developed can only be fertilized after 1-2 years. Generally, in June-July, when orchid leaf buds have extended about 1.5 cm, apply a rotted liquid fertilizer once every three weeks (a dilute concentration of 10% is appropriate). Avoid chemical fertilizers; in high-temperature seasons do not fertilize. In August-September, apply dilute liquid fertilizer once every two to three weeks. Each time orchids are fertilized, it is best done in the evening, and in the morning water with clear water, called "return water."
5. Appropriate watering: Rainwater and spring water are best for watering orchids; tap water or rice-washing water needs to 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 degree of dryness and wetness of the potting soil, and the orchid's growth condition. Water more when there are many leaves, less when the leaves are fine. In April-May, before new shoots have emerged from the soil, the potting soil should be a bit dry; if too wet, new shoots rot easily. June-September is the growth period for new orchid shoots, and the amount of water should be increased; on sunny days, water once each early morning, and absolutely do not water under the scorching midday sun. In autumn, reduce the amount of water as appropriate, and you can use leaf-surface misting to keep the potting soil moist. In winter, control the amount of water even more, keeping it at "eight parts dry, two parts wet."
6. Evening misting: Orchids originally grow in a humid environment, so in dry seasons, besides shading, you must also mist in the evening to increase air humidity and lower the temperature; you can also water the ground (table surface) where the orchid pots are placed. "One cold, one hot" can even more stimulate orchid growth.
7. Wind and rain protection: "February ghost wind" causing old leaves to yellow and fall is a normal phenomenon, and withered branches and fallen leaves can be cut off. Orchids can take light rain, but hate plum rains, heavy rain or continuous rain, otherwise the heart and leaves rot easily. 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 often be cut off to improve ventilation. For precious orchids, if there are too many flower buds, keep only the strong buds, and 1-2 flower buds per pot is appropriate. Spring orchids should have their flowers removed half a month after blooming; precious orchids should have them removed after 7 days, so the spring orchid's leaf buds grow vigorously and bloom better the next 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 and their places of origin vary, their cold resistance also differs, so the time to bring them indoors in winter and their indoor placement are also different. Cold orchids, autumn orchids and Chinese New Year orchids grow in the south and should be brought indoors (or have windows closed and nets drawn) when the temperature is 5°C, and placed in a south-facing sunny spot as much as possible. Spring and summer orchids have strong cold resistance and can be brought indoors only when the temperature reaches 0°C, placed on the northeast side. Around noon on clear, windless days, windows facing south or southeast should be opened and nets drawn for ventilation. Autumn orchids must not have windows opened on clear days at 1-2°C. Of course, if you have a greenhouse, electric lighting can be used for heating.
10. Disease and pest control: The potting soil generally needs sterilization treatment (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, you can brush it off with a damp cloth, and for many pots you can use 500-800 times Bordeaux mixture or Topsin, 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 solution, spraying once a week. To treat the symptoms you must treat the root cause: pots should be spaced appropriately, placed high and low, and ventilation increased, to reduce disease occurrence.
(II) Ecological habits of orchid cultivation
Orchids originated in our country. They like warmth and humidity, and especially ideal is warm winters and cool summers; avoid high temperature and dryness. In winter, it is best if they do not freeze, and keeping 3°C-7°C is most suitable; in summer, 25°C-28°C is appropriate. In their natural distribution, orchid habitats have streams and gullies nearby, receive rain and dew year-round, and require annual rainfall of more than 1000 mm. They require deep topsoil rich in humus, dark brown, loose and fertile, with good water permeability and water retention, slightly acidic soil, pH 5-PH 6.5, and hate waterlogging.
Orchids like shade and require short sunshine duration. In their natural distribution it is shown that spring orchids require tree canopy density of 0.7-0.95; cymbidium orchids require 0.5-0.8, with a slightly longer light duration than spring orchids; Jian orchids, ink orchids and cold orchids also require large canopy density for shade. Cymbidium plants have a dormancy habit in their native areas, which depends on the rainy and dry seasons. Usually the dry season is in winter, which is the orchid's dormant period, and the rainy season is in spring and summer, which is the orchid's growing period, when it can continuously produce buds and bloom.
(III) 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 dividing once every three years. Any plant that grows robustly with densely clustered pseudobulbs can be divided, and after division each clump must retain at least 5 connected pseudobulbs. Before division, reduce watering to make the potting soil relatively dry. When potting after division, first cover the drainage hole at the bottom of the pot with broken tile pieces, then spread coarse gravel to occupy 1/5 to 1/4 of the pot depth, then add coarse-grained soil and a small amount of fine soil, and then plant with sandy loam rich in humus. The planting depth should just bury the pseudobulbs into the soil; leave a 2 cm rim at the edge of the pot, spread Selaginella or fine gravel on top, and finally water thoroughly, place in a shady spot for 10-15 days, keep the soil moist, gradually reduce watering, and carry out normal care.
2. Seed propagation: Orchid seeds are extremely fine, with only one incompletely developed embryo inside the seed and very low germination ability. In addition, the seed coat does not easily absorb water, so sowing by conventional methods cannot germinate; therefore orchid fungi or artificial culture medium are needed to supply nutrients for germination. For sowing, it is best to choose fruit that has not yet split; after sterilizing the surface with 75% alcohol, take out the seeds, soak them in 10% sodium hypochlorite for 5-10 minutes, take them out and rinse 3 times with sterile water, then sow them in culture bottles containing medium, and then place them in a dark culture room, keeping the temperature at about 25°C; after they sprout, move them into the light and they can form protocorms. From sowing to transplanting takes half a year to a year. Tissue culture has already been successful, and where conditions permit this method can be used for propagation.
(IV) Orchid cultivation techniques
1. Site selection: Requires open space all around, good ventilation, close to water surfaces, humid air, and no coal smoke pollution. On the southwest side of the site, evergreen broad-leaved 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 preferable; do not use water containing salt or alkali. If using tap water, it should be left standing for several days before use. Watering should depend on temperature conditions: in spring the amount of watering should be less, in summer more; the plum rain season coincides with orchids sprouting leaf buds, so the potting soil should be slightly dry; after autumn the weather turns cooler, so reduce the amount of watering as appropriate and just keep it moist. In winter indoors it should be dry, reducing the frequency of watering, and watering should be done at noon. Orchids can take light rain, but continuous rain or heavy rain easily causes heart and leaf rot, so attention must be paid to rain protection.
3. Fertilizing: For growing orchids, cake fertilizer is suitable. Mix 4 parts plant ash, 10 parts bean cake and 10 parts bone meal evenly, put them in a vat, add water several times until the bean cake is soaked through, then cover and seal, and after one year of decomposition, make it into dry granules. When using, just place it on the pot surface. If using whole manure, it should also be decomposed for one year, then diluted with water, filtered and used. Generally, fertilizing starts in May and stops at the Start of Autumn, with the principle of thin fertilizer applied frequently. Fertilizing should be done in the evening, and the next morning water once with clear water.
4. Shading and cold protection: Except in early spring and winter, they should all be placed under an open-air shed. The shade shed requires good ventilation. When orchids first come out of the room in March-April, they can get more sun, and afterward the shading time gradually increases. In winter, orchids must be moved indoors for cold protection, and keeping the room temperature at 1°C-2°C is enough. In addition, after orchids come out of the room in spring and before they enter the room in autumn, attention must also be paid to frost protection.
5. Pest and disease control: The main pests and diseases of orchids are:
(1) Southern blight: Mostly occurs in the plum rain season. Attention should be paid to ventilation and light transmission, and good drainage of the potting soil for prevention. After onset, remove the infected potting soil and sprinkle on pentachloronitrobenzene powder or lime.
(2) Anthracnose: Present year-round, and more rampant in high-temperature, rainy seasons. In addition to improving environmental conditions, during the disease period you can first spray with 50% thiophanate-methyl wettable powder at 800-1500 times solution, once every 7-10 days, and then supplement with 1% equal-amount Bordeaux mixture, once every half month.
(3) Scale insects: They reproduce fastest under high temperature, high humidity and poor air circulation. Use conventional methods for control.
In summary, to grow orchids well, you must master their natural growth environment conditions, take reasonable measures and strengthen care and management. According to "Orchid Growing Tips": "Do not come out in spring, do not sun in summer, do not dry in autumn, do not wet in winter" - this is a summary of our country's orchid growing experience.
A brief discussion of rational pesticide use for orchids
Fungicides are agents for preventing and controlling crop diseases. In our usual control of orchid diseases, we must choose according to the different properties and modes of action of different categories of fungicides. One category is protective fungicides, whose role is to treat plants or the environment in which plants live before pathogens invade. They need to be used before the plant comes into contact with pathogens or before disease occurs to achieve results, such as Bordeaux mixture, lime sulfur mixture, mancozeb, zineb, etc. There is also a category of therapeutic fungicides, which we often encounter; their characteristic is systemic action. These fungicides are used after the pathogen has invaded the plant body or the plant has already become diseased, at which point they are applied to reduce or eliminate plant disease. Applying the pesticide in the early stage of plant disease gives better results.
The initial and peak stages of disease for different pathogens also differ, and are greatly influenced by the external environment, especially the growth and development status of the infected crop and temperature and humidity, (therefore, we must grow strong orchid seedlings). When preventing and controlling diseases, it is better if everyone can be familiar with the living habits and epidemic patterns of the pathogenic bacteria, and can do disease control according to different seasons and temperature environments; this plays a huge role in the effective exertion of pesticide efficacy. Crop diseases caused by various pathogens are different, and the disease symptoms are also obviously different, so when choosing fungicides, the pesticide must be suited to the disease. Moreover, the efficacy should be significant and lasting; you should not blindly pursue high efficiency, broad spectrum, or even "all-purpose" pesticides, treating ten thousand diseases with just one pesticide. This is definitely not acceptable. When using pesticides, attention should be paid to preventing the development of pathogen resistance, that is, you cannot continuously use the same fungicide, nor continuously use the same category of fungicide several times in one growing season; especially for systemic agents, their frequency of use should be restricted. For example, in production, systemic agents can be used in combination or rotation with chlorothalonil, mancozeb, etc.
In our daily pesticide use, we should take corresponding control measures according to the patterns of pathogen infection. When using fungicides to spray directly on 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 relatively high, the concentration of the pesticide used can be appropriately reduced; for pesticides that easily decompose or volatilize under strong light, they should be applied on overcast days or in the evening. Different pesticides all have a certain scope of use; only by understanding them deeply and mastering their usage characteristics can you correctly select pesticides and achieve twice the result with half the effort. Carbendazim is a systemic fungicide commonly used by everyone; it can prevent and control dozens of fungal diseases, and ascomycetes and deuteromycetes are especially sensitive to it, but it is ineffective against diseases caused by bacteria and oomycetes among fungi. Therefore, when it is confirmed that a plant is infected with a fungal disease and repeated use of carbendazim is ineffective, you should consider switching to phenylamide pesticides (such as metalaxyl). This type of pesticide is mainly used for downy mildew, phytophthora disease and pythium disease caused by oomycetes, while its effect on diseases caused by other fungi and bacteria is very poor. Chlorothalonil is a non-systemic broad-spectrum fungicide that has a preventive effect on many plant fungal diseases. It can prevent pathogen spores from germinating, hinder mycelial development and spore formation, and can also control diseases that have developed resistance to carbendazim, but its control effect on diseases caused by soil-borne pythium is poor. Therefore, often change fungicides, (Huakang is said to be able to kill all diseases; I do not know if it is true. When I use it I do not dare be careless and still mix it with other fungicides) to strive for maximum protection of orchid plants and keep them from suffering disease. When orchids grow healthily, orchid enthusiasts are happy too.Figure 1 Ring spot disease + anthracnose (Colletotrichum)
Ring spot disease + anthracnose (Colletotrichum) usual preventive pesticide use:
Pesticide name: 77% Kocide wettable powder; mode of action: broad-spectrum protective fungicide; usage: 1000 times solution / 3-4 times / 7-day interval, spray / leaf underside, leaf surface; can simultaneously prevent: 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 times / 8-day interval, spray / leaf underside, leaf surface; can simultaneously prevent: 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 times / 6-day interval, spray / leaf underside, leaf surface; can simultaneously prevent: anthracnose, leaf spot disease, sooty mold, black spot disease, round spot disease, ring spot disease;
Ring spot disease + anthracnose (Colletotrichum) supplementary notes:
I. Because most control prescriptions for anthracnose are emulsifiable concentrates or mancozeb types, when using pesticides you must pay attention to weather temperature and UV index.
II. When the temperature exceeds 30 degrees, avoid using emulsifiable concentrates and copper agents as much as possible; when the weather UV is too high, try to choose to use pesticides before 5 a.m. or after 6 p.m.
III. It is recommended that during normal pesticide use you can choose to mix fungicides from two prescriptions, so that you can achieve treatment and defense in multiple aspects.Figure 2 Ring spot disease + leaf spot disease
Ring spot disease + leaf spot disease usual preventive pesticide use
Pesticide name: 80% mancozeb wettable powder; mode of action: broad-spectrum protective fungicide; usage: 800 times / 3-4 times / 6-day interval, spray / leaf underside, leaf surface; can simultaneously prevent: 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 solution / 3-4 times / 7-day interval, spray / leaf underside, leaf surface; can simultaneously prevent: brown spot disease, anthracnose, leaf spot disease, ring spot disease, bacterial
Ring spot disease + leaf spot disease supplementary note: Before the leaves of an affected orchid have dried up, ring spot disease is often mistaken for ordinary leaf spot disease if not carefully examined.
2. It is recommended that during normal spraying you can choose to mix fungicides from two formulas, so as to provide treatment and defense in multiple aspects. Image 3: Mild nutrient deficiency disease (zinc, magnesium, iron).
Mild nutrient deficiency disease (zinc, magnesium, iron). Routine preventive spraying: although this is a disease state, it is not contagious. During normal fertilization, supplement some trace elements and fertilizers containing zinc, magnesium, iron and calcium. Mild nutrient deficiency disease (zinc, magnesium, iron) supplementary note: during normal fertilization, supplement some trace elements and fertilizers containing zinc, magnesium, iron and calcium. Image 4: Soft rot + black spot disease.
Pesticide name: 72% agricultural streptomycin sulfate wettable powder; mode of action: antibiotic fungicide; application method: 800 times dilution / 2-3 times / 7-day interval, spray, drench roots; can also prevent: bacterial brown spot disease, soft rot disease.
Soft rot + black spot disease supplementary note: because this is a condition caused simultaneously by fungi and bacteria, two different fungicides must be mixed and used. Since the two fungicides each have their own dilution concentration when mixed, this often confuses beginner orchid growers. Here is a supplementary explanation again: ratio: need 100 jin of water, use the bacterial one, streptomycin sulfate at 500 times, mixed with the fungal one, carbendazim, at 1000 times.
1. 100 jin of water at 500 times streptomycin sulfate means streptomycin sulfate needs to be added in an amount of 100 grams.
2. 100 jin of water at 1000 times carbendazim means carbendazim needs to be added in an amount of 50 grams.
3. That is, using 100 grams of streptomycin sulfate equals "500 times" plus 50 grams of carbendazim equals "1000 times", put both into 100 jin of water and mix for use; only then is the pesticide dosage correctly prepared. Image 5: Leaf tip anthracnose + leaf blight.
Routine preventive spraying for leaf tip anthracnose + leaf blight.
Pesticide name: 25% propiconazole emulsifiable concentrate; mode of action: broad-spectrum systemic fungicide; application method: 1500 times / 2-3 times / 8-day interval, spray / leaf underside, leaf surface; can also prevent: 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; application method: 3000 times / 2-3 times / 8-day interval, spray / leaf underside, leaf surface; can also prevent: 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 note: because this is a cross-symbiosis of two pathogens, it is recommended to use two fungicides for relatively simple control. The mixing method for the two fungicides is repeated here. When two conditions occur simultaneously, two different fungicides must be mixed and used. Since the two fungicides each have their own dilution concentration when mixed, this often confuses beginner orchid growers. Here is a new supplementary explanation: ratio: need 100 jin of water, use the bacterial streptomycin sulfate at 500 times mixed with the fungal carbendazim at 1000 times.
1. 100 jin of water at 500 times streptomycin sulfate means streptomycin sulfate needs to be added in an amount of 100 grams.
2. 100 jin of water at 1000 times carbendazim means carbendazim needs to be added in an amount of 50 grams.
3. That is, using 100 grams of streptomycin sulfate equals "500 times" + 50 grams of carbendazim equals "1000 times", put both into 100 jin of water and mix for use; only then is the pesticide dosage correctly prepared. Image 6: Leaf margin black spot disease.
Routine preventive spraying for leaf margin black spot disease.
Pesticide name: 80% mancozeb wettable powder. Mode of action: broad-spectrum protective fungicide. Application method: 800 times / 3-4 times / 6-day interval, spray / leaf underside, leaf surface. Can also prevent: 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; application method: 3000 times / 2-3 times / 8-day interval, spray / leaf underside, leaf surface; can also prevent: 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; application method: 1500 times / 2-3 times / 8-day interval, spray / leaf underside, leaf surface; can also prevent: 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; application method: 2000 times / 2-3 times / 8-day interval, spray / leaf underside, leaf surface; can also prevent: anthracnose, leaf spot disease, sooty mold, black spot disease, round spot disease, ring spot disease.
Leaf margin black spot disease supplementary note: in fact, many fungicides used for orchid leaf diseases have similar properties, but as our professional introduction we must present all the conditions for orchid growers to understand. In general, the best choice of fungicides is broad-spectrum and systemic pesticides of the two types.
Experience note: in my experience, the key work when buying pesticides is to choose manufacturers with credibility and clearly labeled ingredients, so as to avoid merely having the psychological comfort of sterilization while ending up with fake ingredients, causing the disease to go uncontrolled and missing the golden time for treatment.
Experience note: the second cause of harm is thinking that these pesticides may have insufficient active ingredients and therefore increasing the concentration and dilution. Who knew that this time real pesticide had been purchased, and once the dilution was increased it caused severe pesticide damage. Haha! One can only look to heaven speechlessly. Image 7: Blight disease.
Routine preventive spraying for blight disease.
Pesticide name: 72% Curzate wettable powder; mode of action: systemic fungicide; application method: 1500 times solution / 2-3 times / 10-day interval, drench roots and stems; can also prevent: blight disease.
Pesticide name: 50% Acrobat wettable powder; mode of action: systemic fungicide; application method: 12500 times / 2-3 times / 10-day interval, drench roots and stems; can also prevent: blight disease.
Supplementary note on treating blight disease:
1. At the peak of disease outbreak, continuous preventive spraying 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 solution, 77% Kocide powder at 1000 times solution, spray leaf underside, leaf surface and crown.
3. Miexianan (emulsifiable concentrate) 1500 times + tetracycline (powder) 2000 + dimethomorph (powder) 2000 times solution, spray leaf underside, leaf surface and crown.
4. Antaisheng 500 times + Miexianan 1500 times + streptomycin sulfate 500 times solution, spray leaf underside, leaf surface and crown. "When applying fertilizer and pesticide, you must spray the leaf underside, because plants absorb through the stomata on the leaf underside."
5. About every 20 days, use Dexon 800 times + tetracycline 3000 times solution to thoroughly drench the roots.
6. Fungicides must be alternated, so as not to produce resistance and delay treatment of the disease. 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 preferably be loose and breathable, well aerated, with an appropriate amount of fertilizer, and free of hidden pests and diseases. The composition of the 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 all are substrates on which orchids rely for stabilizing the plant and for growth and development.
(1) Formula of the growing medium.
In East China, orchid growers generally prefer orchid mud from places such as Shaoxing and Yuyao. In recent years, Emei He Wangpai Xiantu has also been welcomed by people, but these growing media are limited in quantity and expensive, and can only be used for repotting. Large-area ground planting requires hundreds or thousands of tons of growing medium, so only local materials can be used. After many years of practice and repeated screening, we determined the best formula: four parts yellow sand soil, four parts sawdust, two parts river sand; if using yellow loam, then one part river sand, one part sawdust, one part yellow loam. All are thoroughly mixed. The pH value of the prepared growing medium should be between 6.5-6.8, loose and breathable, with excellent water retention and aeration, and comprehensive nutrition. River sand and sawdust serve to conduct water and air; sawdust is decomposed by bacteria and can slowly release nitrogen, phosphorus, potassium, etc. Yellow loam also contains various trace elements. After many years of observation, this formula is very suitable for orchid growth. It is especially suitable as a substrate for domesticating and cultivating wild orchids, suitable for Cymbidium goeringii and Cymbidium faberi, and also very ideal for Cymbidium ensifolium and Cymbidium kanran, with flowering rate and stress resistance both significantly increased.
(2) Bamboo root mud.
This refers to the soil at the roots of bamboo clumps that have been planted for many years. Because of the spreading growth of bamboo rhizomes and bamboo roots and the decay of bamboo leaves and shoot sheaths, this soil becomes loose in structure, well drained, and has a certain fertility without being excessively fertile, making it 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 the bamboo root mud, with sandy loam being best; second, the age of the bamboo clump planting, the longer the time, the more fully the effects of bamboo roots, bamboo leaves and bamboo rhizomes; 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 the plants of green manure (Chinese milk vetch). Mix vetch chaff with bamboo root mud or ordinary sandy loam, pile it up and compost it, and it becomes vetch chaff soil. Its preparation method is: choose a rain-sheltered site, spread a layer of soil, then a layer of vetch chaff, pour once with * manure water, and pile up layer by layer in this way; after piling, sprinkle water on the surface to moisten it, then coat it with thin mud to seal it. After piling and fermenting for half a year, it can be used.
When using, mix it into other growing media in proportion.
(4) Leaf mold.
Made by piling fallen leaves or green grass and tall stalks, watering or applying fertilizer, coating with thin mud to seal, and after composting and screening. It is best to use green grass that has not set seed, and to compost it fully to kill pests, diseases and weed seeds, otherwise there will be many weeds in the orchid pot later.
(5) Mountain soil.
That is, the mountain forest soil where wild orchids originally grew. It is formed by dead branches and fallen leaves piling up and rotting over many years and mixing with the soil. Naturally formed leaf mold contains rich humus, is loose and breathable, and is very suitable for orchid growth. When transportation is convenient, digging up mountain soil in large quantities to plant orchids is relatively simple and economical, and is even better for domesticating raw orchids. The humus soil under broad-leaved forests, especially the leaf mold under chestnut trees, is a very ideal soil for orchids.
(6) Pond mud.
In conjunction with winter repairs of ponds and fish ponds, dig out the mud, dry it in the sun, then break it into fine particles. It can be used to cultivate all flowers, including orchids.
(7) Field soil.
That is, select loose topsoil from the field, mix in a little sandy soil or a small amount of rice hull ash, then add some composted manure or fermented and decomposed organic fertilizers such as soybean cake and rapeseed cake, to promote improvement of soil structure and enhance fertilizer efficiency. After turning and mixing evenly many times, screen it. This soil is nearly neutral and not as good as humus soil. Therefore, it is only used reluctantly when there is no suitable humus soil or mountain forest sandy loam, and is mostly used for cultivating common orchids.
(8) Cow manure soil.
Crush and grind fermented dry cow manure finely, and mix it into sandy soil or field topsoil in a 1:3 ratio to prepare it. It is best to choose cow manure from cows fed dry feed in winter, because although the dry forage is finely broken after rumination in the cow's stomach, it is still elastic, and as plant fiber it contains certain nutrients. This cow manure soil is soft and rich in fertilizer, and is extremely suitable for the aerial roots of orchids. In Taiwan, China orchid circles, people often use this cow manure soil as a filling material for cultivating terrestrial orchids, with very good results. Abroad, 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 manure, fully mixed and then used. The cultivation substrate for epiphytic orchids is mainly moss and ferns, with a small amount of leaves, small pieces of charcoal and crushed dry cow manure added. Before using soil to plant orchids, expose the soil to sunlight for disinfection and sterilization. In summer, spread the soil out and let the sun expose it for more than 3 days, which can kill pathogens and insect eggs in it. Before use, the growing medium should be tested and its pH adjusted. For soil that is too acidic, lime can be used to adjust it. For soil that is too alkaline, calcium superphosphate, ferrous sulfate, etc. can be mixed into the soil. In short, it is appropriate to control the soil pH at neutral to slightly acidic (that is, pH 5.5-7). Using organic fertilizers, such as compost made from green grass and leaves, and adding them to the soil to change the soil pH is a better method. In addition, before planting orchids, the nutrient soil should be screened and graded, separating large particles from small particles.
When planting orchids, place the large particles at the bottom of the pot to facilitate drainage. At the same time, the degree of soil dryness and wetness should also be adjusted well, neither too wet nor too dry. It is best to ball the soil in the hand and squeeze hard so that the soil forms a ball; then open the hand and shake it lightly, and the soil disperses into particles again. Such dryness and wetness is suitable.
2. Preparation of the orchid growing site. 1. Productive ground planting. The original environment for terrestrial orchids is growth among mountain forests and secluded valleys, with high and refreshing terrain, shade from trees, and a humid microclimate. The temperature difference is small and the air is clean.
When introducing and domesticating them, their wild environment should first be simulated so that they can be planted with abundant flowers and lush leaves. At present, with industrial development and urban modernization, greening work cannot keep up accordingly for the time being, and they are polluted by factories and vehicles. Therefore, orchids cultivated in cities are not as robust as those grown in suburbs. There is a gap with the native environment of wild orchids, and a great difference from the meteorological factors of the native places of Cymbidium kanran and Cymbidium ensifolium, so careful design was made for the domestication and planting site and practical arrangements were made for regulating environmental factors.
The orchid nursery covers about 1.5 ten thousand sq m and is rectangular. In the nursery there is a rectangular pond for storing rainwater. In the nursery, every about 2.5 m a 2.5 m high moso bamboo pole is fixed, and bamboo is tied horizontally above to form a frame, used to lay the first layer of shade net. At 20 cm below the first layer of shade net, another horizontal thin moso bamboo is placed, used to lay the second layer of movable shade net. The first layer of shade net is basically fixed from spring to autumn, and the second layer can be retracted or spread as needed. Carefully regulate light and temperature. The seedbed width is 1.2 m, length 12-16 m (depending on terrain), height about 30-40 cm (5-7 bricks high), seedbed spacing 50 cm, passage width 130 cm. Convenient for daily management. In winter, every two beds are tied with a plastic greenhouse for warmth. On snowy days, pay attention to clearing snow and avoid too much snow crushing the plastic shed. About every mu (one mu ≈ 667 sq m) of land, build two water tanks with a storage capacity of 1 cubic meter to treat tap water. In winter, place 100-150 watt bulbs about 4 m apart inside the plastic shed, mainly for raising temperature.
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, corners of walls or scenic areas to plant appropriately in the ground, but the original poor clay must be dug out and replaced with loose humus soil or good field topsoil.
When winter arrives, spread some rice straw over the soil surface at the roots to avoid freezing the orchid roots. If there is severe cold, it is also necessary to lay straw curtains or other soft coverings over the leaf clumps to prevent cold damage. For this kind of ground-planted orchid cultivation, apart from strengthened management and protection during the hottest midsummer, it can generally be managed extensively and allowed to grow naturally. Orchids planted in the open field are all common types without petal-type classification. In spring of the next year, after the weather turns warm, the cold-protective coverings can be removed. After many years of growth, as long as they are watered and fertilized in a timely manner, their adaptability is still relatively strong, and they can bloom abundantly every year, with delicate fragrance drifting far, making them a fine item to adorn the countryside.
However, when arranging ground-planted orchid cultivation, besides considering the quietness of the layout,
(2) Pot cultivation of orchids.
This also refers to cultivating orchids under a shade shed.
For potted orchid cultivation, it is best to use clay pots, that is, unglazed earthenware pots. They have good air permeability, can filter water, and are cheap. They are economical and practical orchid-growing items. But clay pots are rather rough and not beautiful, and unsuitable for exhibitions. Porcelain pots or glazed pots are beautiful in appearance, but their air permeability and water filtration are very poor. If used for long-term orchid cultivation, they easily rot the orchid roots, making it difficult for orchids to grow vigorously. Therefore, when using porcelain or glazed pots to grow orchids, more drainage tiles must be placed at the bottom of the pot, or fillers such as clam shells; moreover, watering must be controlled and not excessive. If orchids are grown in clay pots, they can be slipped into larger porcelain or glazed pots when participating in exhibitions. Yixing purple sand pots are beautiful and elegant in appearance, and also have a certain air permeability, making them relatively suitable for orchid cultivation. Newly bought orchid pots must be soaked in water for several days; especially newly kilned clay pots must be allowed to absorb enough water and completely eliminate their fiery dry nature. 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 intense and ground temperature rises, it harms the orchid plants; during thunderstorms and plum rain seasons, hot and humid air rises even more, easily steaming the orchid roots; moreover, being close to the ground, ventilation is poor. This benefits aerial root growth. To reduce the above effects, orchid pots can be placed on orchid benches built from cement boards, facilitating upward and downward convection, continuously supplying fresh air, promoting orchid respiration, enhancing metabolic function, accumulating nutrients and energy production, making orchids grow robustly, and also avoiding damage to orchid roots by ants, slugs and the like. If conditions are limited, an empty clay pot can be turned upside down on the ground, and then the potted orchid placed on top.
3. Orchid room cultivation. The orchid room is mainly for terrestrial orchids to overwinter.
Different types of orchids have different ecological habits, so the time for entering the room for winter and the room temperature requirements are also different. For terrestrial orchids, as long as the temperature is not lower than 7°C-8°C, most can be cultivated in the open. In Jiangsu and Zhejiang, the custom is that after the Start of Winter, Cymbidium ensifolium, Cymbidium kanran and Cymbidium sinense, which require slightly higher temperatures, are moved indoors for cultivation, while some Cymbidium goeringii and Cymbidium faberi with flower buds are moved to corridors or cold-protected places to avoid attack by early frost and affect flower bud development. After Minor Snow, potted orchids cultivated from pseudobulbs and thin weak small plants, especially orchids of the pure-color petal type, are gradually moved indoors and placed on orchid shelves near windows so as to receive sunlight. After Major Snow, all potted orchids are moved indoors for maintenance. Before orchids enter the orchid room, first wash the area around the orchid pots clean, which can prevent mud stains from carrying insect eggs, mold, etc., and also looks clean and elegant. When placing orchid pots, pay attention to reasonable arrangement, convenient for sunlight penetration and conducive to ventilation. When terrestrial orchids overwinter indoors, the key is to manage temperature and humidity well. Generally, room temperature should be kept above 7°C-8°C, and for Cymbidium sinense it should ideally be kept at 10°C-15°C. After orchid pots are brought indoors, if the weather is not yet severely cold and freezing, the south-facing windows should be opened around noon, and a small vent on the north side opened, to facilitate indoor air circulation. In the evening, if the indoor temperature is still above 5°C, the small north and south vents can be opened slightly; if below 5°C, all windows should be closed. In deep winter, only on windless sunny days at noon should windows be opened slightly for a little ventilation; when the sun begins to slant, doors and windows should be closed, and in the evening straw curtains or cotton cloth curtains should be hung. If the temperature continuously drops below 3°C-5°C, a coal stove with a chimney pipe can be used for heating. After the Start of Spring, the climate gradually warms, and on clear noons all doors and windows of the orchid room can be opened, but attention should be paid to temperature changes; in the afternoon when the temperature gradually drops, the south windows should be half opened and half closed; before nightfall, all should be closed again.
During this period, the orchid room temperature should preferably be kept at around 10°C. If the temperature is too high, it will cause early-flowering varieties of Cymbidium goeringii to bloom early, and the flowers also tend to wither early. In early spring, it is even more necessary to prevent late spring cold, which affects flower bud growth and may even freeze orchid roots.
After Awakening of Insects, all Cymbidium goeringii and Cymbidium faberi without flower buds can leave the room and be placed on open-air benches, with reed curtains added on the shed frame at night to prevent frost damage. All kinds of orchids with flower buds should still remain in the orchid room for maintenance, and only after Pure Brightness 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 dryness and wetness of potted orchids. The pot soil should preferably be dry. When watering is needed 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 pot soil is completely dry before watering. When watering, first move the potted orchid down and place it on the ground, and water along the water groove at the pot rim. Never let water soak into the leaf clusters. The orchid pot can also be placed in a water vat and shallow-soaked for several minutes, with water limited to reaching the waist of the pot. When watering, if water soaks into the leaf sheaths, promptly wipe off the water marks with a dry cloth, or let sunlight dry them before moving them back indoors. Because orchids are placed indoors for a long time, many dust particles often adhere to the leaf surface, hindering metabolism. On clear warm days, at noon, move the pots outdoors into sunlight and use a fine-holed watering can to spray and clean the leaf surface, washing away dust and dirt. After the water marks dry, move them back indoors. If the water marks are not dry, the wet parts of orchid leaves easily turn black and wither. During indoor orchid cultivation and heating, the indoor temperature is often relatively high, the 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 passages and walls and let it evaporate, so as to regulate temperature. In short, for indoor orchid cultivation, whether the orchid plants in the pot or the moss on the pot surface should remain green. If you are an amateur orchid grower, due to limited conditions, you can use a south-facing sunny spot along a wall outdoors, leaning against the wall on one side, and build a single-slope ground box with bricks on the other three sides. The size can be determined according to the number of pots. On the sloped surface of the ground box, install a wooden-framed glass window or plastic film window that can be opened and closed. For orchids with long and tall leaves, place them in a higher position near the wall; they should be placed on inverted empty flower pots, or on bricks, wooden strips, or cement boards stacked to a suitable height. Low orchid pots are arranged row by row forward, and all leaf tips or the tops of ringed leaves must not touch the glass or plastic film of the window surface. In severe cold seasons, whenever the temperature is too low or on windy and snowy days, the sloped window must be covered with straw curtains or other coverings sufficient to prevent cold air from entering. When the weather is clear and mild, especially after the Start of Spring, when sunlight shines, the cold-protective straw curtains can be removed; at noon when sunlight is relatively strong and the temperature is slightly higher, the covered window can be lifted to leave a gap to regulate fresh air. After the sunlight slants, the covered window should be closed immediately. In daily care, great attention must be paid that too many water droplets must not condense on the glass of the covered window, to prevent them from dripping into the leaf clusters; wet parts often turn black and rot, and may even die.
3. Planting orchids. 1. Planting timing. Whether repotting or newly planting, the choice of timing has a great influence on the survival, growth vigor and development of orchids. Therefore it is very important. Generally, the more suitable time is the dormancy period of orchids, that is, March-April, before new shoots emerge from the soil; in terms of seasonal timing, it is between the Spring Equinox and Pure Brightness. If after new shoots emerge, operation is very inconvenient, and a little carelessness may break or injure the new shoots. When the dormancy period of orchids is about to end, and new shoots and new roots are at the stage of being about to grow but not yet grown, planting at this time is best; soon after planting, they can root and sprout and resume normal growth. If planted too early, orchids after planting are not easy to revive, and if encountering low temperature, cold wave, late frost or spring thunder, cold damage is often caused. In the Yangtze River basin, orchid rooms are rarely heated in winter. Winter is very cold, so division in severe winter is not advocated. To make division convenient, the soil can be allowed to dry appropriately before division. This makes the roots whitish and produces inconspicuous shrinkage, making the originally crisp and easily broken fleshy roots soft, so that when dividing and potting, too many roots will not be broken. In larger orchid nurseries, the planting workload is large and takes a long time from beginning to end. Precious varieties should be arranged for planting at the best time. Common varieties can be postponed or advanced as appropriate.
2. Using orchid seedlings for propagation. For propagation, orchid seedlings that grow well and are free of pests and diseases should be selected.
After 2-3 years of cultivation, orchids need soil replacement or repotting, and at this time division propagation should be combined. When repotting, support the bottom of the flower pot with the left palm, carefully extend the fingers of the right hand into the orchid leaf cluster to block the pot soil, then lay the orchid pot on its side, tilt the pot body sideways toward the person, and touch the lower edge of the pot mouth to the ground. At this time, lift the pot slightly with both hands simultaneously, so that the lower edge of the pot lightly knocks the ground, loosening the pot soil. Rotate the pot body, change the contact point where the lower edge of the pot mouth knocks the ground, and let the pot soil gradually loosen evenly and separate from the flower pot. Support the orchid plant with the right hand, and remove the flower pot with the left hand. If the orchid plant is too tall, it is better to knock 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 pot soil separates from the pot, lay the orchid seedlings and pot soil flat, so that the soil ball does not suddenly loosen and crack, causing the orchid root system to break. Then carefully pat the soil ball gently to loosen it, and gradually shake off the old pot soil. Carefully grasp the pseudobulbs to avoid injuring leaves and tender shoots, especially protecting the root tips. Cut off already yellowed leaves, decayed bracts on the pseudobulbs, and rotten, dry, hollow old roots. But for leaves on pseudobulbs with new shoots, they should be retained as much as possible to promote good growth of new shoots. For the larger clumps that have been selected and cleaned, find the natural gap where the 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 use both hands to hold the bases of the two clumps, gently shake and slowly pull along the road to divide them into two clumps. Properly prune the separated orchid clumps, then soak them in a 800 times water-diluted thiophanate solution for 10-15 minutes, only soaking roots, not leaves; a 1000 times potassium permanganate solution can also be used for disinfection. Note that only the wounded parts should be disinfected, then air-dry the orchids in a cool, ventilated place. When the orchid roots 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 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 particles or bean stones, generally about 1/2-1/3 of the pot's inner height. The remaining clear height above is about 10-15 cm, reserved for the growing medium layer. Its specific height should be determined according to the orchid species, the length of orchid roots and the height of the pot. Do not fill the padding too densely or too solidly; some gaps should be retained. Practice has proved that some new roots can grow well in the gaps of the padding layer.
(2) Planting.
On the padding layer, first fill 2-3 cm of growing medium, press slightly with the hand, then place the orchid upright on it. According to the plant and flower pot size, several single plants, 2 clumps, 3 clumps or more clumps can be planted in one pot. 3 clumps should be planted in a tripod arrangement. 4 clumps can be planted in a square. 5 clumps should be arranged in a plum blossom shape. Orchid roots should spread naturally, and leaves should spread in all directions. Slowly place the orchid roots into the pot so that the orchid roots spread naturally and as much as possible do not rub against the inner wall of the pot. After the orchid plant enters the pot, gradually fix the posture of the orchid plant. For one clump per pot, the old pseudobulbs should be placed toward one side, leaving room for new shoots to develop. For multiple clumps per pot, the old pseudobulbs of each clump should be relatively gathered in the middle of the pot, so that new roots and new shoots developing outward each have enough space.
(3) Filling soil.
When planting, hold the leaves with one hand and add nutrient soil with the other, hold the base of the orchid plant and lift it slightly upward to stretch the root system, while shaking the orchid pot. Let the growing medium go deep into the root zone; continue adding soil and shaking the orchid pot to adjust the position and height of the orchid plant. Press with the hand along the pot edge, but do not press too hard to injure roots. Continue adding soil and pressing until the pot surface soil is 2-3 cm above the pot mouth, slightly in a steamed bun shape. The growing medium should cover all orchid roots, up to the base of the pseudobulbs. As for the depth of soil filling, tradition holds that Cymbidium goeringii should be shallow and Cymbidium faberi should be deep, but generally the leaf bases on the pseudobulbs should not be 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 plants: neither a large pot with small and few plants, nor a small pot with large and many plants. Generally, the number of plants should be based on the principle that after 2-3 years they will just fill the pot. Plant size should match pot height. This is conducive to growth and also meets ornamental requirements.
(4) Top dressing.
After planting is completed, spread a layer of small stone particles or moss on the surface of the pot soil, preferably high-quality moss from under the forest. It is both beautiful and can regulate moisture, and can also protect the leaf surface from being polluted by muddy water, and prevent new shoots from being infected by pathogens in the soil and rotting at the heart; in addition, it can also reduce the washing effect of rainwater on the pot soil and keep the pot soil loose.
(5) Watering.
After planting is completed, water the first time immediately. The pot soil must be thoroughly wet. The water droplets should be small, and the impact force should not be strong. If placed in a water basin to soak, never soak too long. Once the pot soil is soaked, immediately take the orchid pot out, then move it to a shaded place for maintenance.
4. Maintenance management after planting. Mastering orchid cultivation skills is certainly very important, but managing and maintaining orchids well is even more difficult, hence the saying "three parts planting, seven parts maintenance." Orchid maintenance requires understanding the environment, accumulating maintenance experience, and patience and care. The most important thing is to understand the laws of orchid growth and development: when they sprout, when they grow leaves, when they bloom, when they dormant. Then carry out maintenance and management from aspects such as temperature, humidity, watering, fertilizing, ventilation, plant protection, cherishing leaves and protecting flowers, and you will certainly grow orchids well.
1. Cherishing leaves. Orchid leaves are soft and beautiful but not weak, upright and firm but not rigid.
Orchids are moving and lovely, but good flowers do not come often, and there is no way to deal with flowers falling; but orchid leaves remain green through the four seasons, forever preserving vitality, giving people year-round enjoyment. The elegance of orchids is shown both in the flowers and entrusted to the leaves.
And lush leaves are also the prerequisite for good flowers. If the leaves are healthy and lush, they manufacture abundant nutrients themselves, and then the flowers are many and beautiful. If the leaves are poor while the flowers are many, it is merely a sign of rapid decline. The focus of cherishing leaves is first to control shade density, air humidity, appropriate water and fertilizer, and maintain good ventilation. Make orchid leaves lush and healthy, green and glossy. Also strengthen pest and disease control, and prevent wind, rain attack and mechanical damage. In addition, preserve the leaf tips. The ends of orchid leaves are like sword tips, brush tips, eyebrows, able to convey meaning and spirit. Losing leaf tips makes them appear abrupt and dull. To preserve leaf tips, the key is to ensure sufficient water and nutrients needed by orchids, and loose and breathable pot soil, so that the root system is developed and intact, the plant grows vigorously, and no scorched tips occur. Some people say that the sign of good orchid cultivation is that the leaf tip can pass through the eye of a needle, which means the leaf tip is intact and the tip is undamaged. The leaf tip shapes of different orchid species differ: some are acuminate, some obtuse and rounded, some notched, some upturned; as for leaf color, some orchid varieties have gold tips or silver tips (that is, the leaf tip is yellow or white), showing their preciousness and rarity. This is another layer of interest in appreciating leaves. In daily maintenance, pay attention to protecting orchid leaves, be light and careful in operation, do not bump orchid leaves, and maintain their natural posture.
Carefully clean polluted leaves, and do not let sprayed water accumulate in the center of the leaf cluster. Dead yellow old leaves and diseased leaves should be cut off in time. For partial cutting of orchid leaves, cut diagonally at an appropriate part, and the formed sharp angle should be less than 30. Some also cut twice, but they must not be cut into a flat head.
2. Protecting flowers. After flower buds emerge from the soil, if there are too many, they consume excessive nutrients from the mother plant, hindering the formation and robust growth of leaf buds. Excessively thin and small flower buds should be removed as early as possible. For each orchid seedling, leave one flower bud z, and that is enough.
Each pot should retain 3-5 flower buds. Appropriately retain flower buds according to the orchid variety, pot size, and number of seedlings. To protect and develop precious varieties, all flower buds can also be removed to let them multiply abundantly. During the period from flower bud elongation to flowering, maintain appropriate light so that the flower color is bright and full, rich in luster and with sufficient fragrance. If light is too weak, the flower color is pale and lacks luster. Flowers that remain open too long consume nutrients and hinder sprouting and leaf growth and flowering the next year. Cymbidium goeringii flowers remain open for about half a month; after they fade, the flower scapes 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 snapping off flower scapes, stabilize the leaf base with one hand and press the flower scape to one side with the other, then it can break from the base and be pulled out, or it can be cut off. The removed flower stems can be placed in a vase and enjoyed for many more days. Generally, orchids after flowering are not allowed to pollinate and set seed, especially not very robust and precious varieties, otherwise flowering the next year will be affected. If hybrid breeding is to be carried out, artificial pollination should be carried out at the appropriate time. And the mother plant should be carefully managed so that its seeds are full and mature.
3. Temperature. Most areas of our country are in the temperate and subtropical zones, while orchids generally originate in places with mild and humid climate, relatively high annual average temperature, and a long frost-free period. In Northeast and Northwest China, orchids are rarely cultivated, mainly due to temperature constraints. The northernmost distributed Cymbidium plants in our country are Cymbidium goeringii and Cymbidium faberi. On their distribution line, there is frost or short-term snow accumulation in winter, and relatively high temperatures in summer. However, because orchids mostly grow in mixed broad-leaved 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 for overwintering, and 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 moved them 600-1000 km north from their original producing areas, and 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 next 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 in winter also need indoor cultivation or heating in sheds. In provinces and regions such as Fujian, Guangdong, Guangxi, Yunnan, Sichuan and Taiwan, China, Cymbidium kanran and Cymbidium ensifolium generally do not need to overwinter indoors in winter. In Jiangxi, Hunan and parts of Sichuan, certain measures are still needed in winter to protect orchids.
Orchid temperature requirements: the germination temperature of orchid seeds 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 dormancy period of orchids, the temperature can be lowered. For example, Cymbidium goeringii and Cymbidium faberi require a minimum nighttime temperature in winter of 4°C-6°C, and dropping to 0°C is also acceptable. Under dry conditions, even if plant leaves drop to minus 2°C-3°C, it does no 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 make flower buds differentiate, and the relationship with day length is not very great. But the more light orchids receive, 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 for growth and development than indoors. The purpose of regulating temperature mainly has 3 aspects, namely: preventing cold in winter, preventing summer heat, and changing the flowering period. When winter temperature is below 0°C, orchid leaves and flower buds are susceptible to cold damage, leaves show water-soaked black spots, and flower buds wilt. If the temperature drops suddenly and sharply or there is a particularly severe frost, the damage is even greater. But winter temperature being too high is 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 summer heat, the leaves turn yellow, become rough and lusterless, and are susceptible to disease invasion, often with decay starting at the leaf base. 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 plain and urban cultivation conditions, the flowering period of orchids is often 15-30 days earlier than under original wild conditions. Using this biological characteristic, temperature can be appropriately adjusted to advance the flowering period by half a month to one month. Especially for species that bloom in spring, flower buds are generally already formed in July-September of the previous year. Once they pass the hibernation 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 an enormous 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. What is important is that 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 approximating the original orchid producing area. In summer, double-layer shade 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 for warmth. When the air temperature is as low as 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 conducive to nutrient storage and avoids cold damage. In addition to building earthen 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 slow 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 mud ground, with a maximum daytime difference of up to 4.4°C, helping to avoid cold damage; while in summer the air temperature over grassland is much lower than over cement ground, helping prevent summer heat and lower temperature. In summer, it is appropriate to spray or sprinkle clear water in the air, on the ground, on flower benches 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, enlarging water surfaces nearby also has this effect, such as ponds, storage tanks, ditches, water vats, etc. Greenhouses need curtains hung on the glass to block light and prevent heat. In hot times, pay more attention to ventilation and strengthening air convection for heat dissipation, partially lifting the coverings on the shed; in the orchid room, open doors and windows to avoid accumulation of hot air. In temperature regulation, besides air temperature, soil temperature should also be noted. Orchid roots grow in the soil, and the temperature of the pot soil has a direct impact on their physiological functions. Under general conditions, soil temperature and air temperature are positively correlated. When air temperature is high, pot soil temperature also rises, but the change process is relatively slow. First, prevent direct sunlight from shining on flower pots and heating the soil and pot, scorching orchid roots close to the pot wall; also note that when watering, the water temperature should be close to the soil temperature and not too different. There is another issue worth discussing, namely the relationship between artificial protection and the orchid's own adaptability. Like all plants, orchids have adaptability to the external environment. They are not inherently delicate. Therefore, when orchid growers protect orchids from summer heat and winter cold, their measures should be moderate. Covering too densely and for too long will inevitably weaken their stress resistance. In our orchid nursery, the Cymbidium kanran and Cymbidium ensifolium introduced and domesticated from 600-1000 km to the south, in addition to protective measures, are gradually allowed to enhance stress 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, let alone root hairs, so the surface area through which they absorb water is small; in contrast, orchid leaves grow in dense clusters. Transpiration from the leaf surface is relatively high, so only when the air is humid can a balance be maintained between water absorption and transpiration. In the native habitats of orchids, rainfall is abundant during the growing season, the air is moist, and relative humidity is above 80%; this is especially true of Cymbidium sinense, which grows beside streams where water mist is often present and relative humidity is around 90%. One important reason orchids are difficult to grow in the north is the dry air. It is also generally difficult to succeed with orchids in ordinary urban homes and on balconies, and insufficient humidity is a major factor. When air humidity is low, orchid leaves are rough, dull and lusterless; when air humidity is suitable, the leaf surface is moist and green. Generally, the humidity required during the growing season of orchids should not be lower than 70%, and in the winter dormant period it is about 50%; humidity at night should be somewhat higher than during the day. Humidity and ventilation are two relative and contradictory factors: too much ventilation lowers humidity, and in northern winters and springs dry winds blow frequently and humidity cannot be maintained, which is unfavorable for orchid growth, so ventilation should be appropriately reduced.
Methods for regulating and increasing air humidity:
Plant many trees, bamboo and grasses around the orchid nursery. The root systems of these plants can absorb large amounts of water from underground and then release it through the leaves above ground. They can also retain surface water, which gradually transpires and increases the content of water molecules in the air, thereby raising air humidity. When the ground is dry, sprinkle water on the ground, benches and walls, which also has the effect of lowering temperature. You can also mist or sprinkle water in the space where orchids are grown or on the leaf surface. However, sprinkling or misting the leaf surface should not be done at night; if the leaf surface must be sprinkled in the evening, be sure that the leaves can dry again by night. In southern China there are sometimes long spells of rainy weather, especially during the plum rain season when humidity is excessive, so doors, windows and coverings should be opened for ventilation. Orchids like warmth and moisture, and when humidity is high and ventilation is good, orchids grow robustly; but under low temperatures without ventilation, water vapor condenses into droplets, which harms new shoots and easily causes disease, so low temperature with high humidity should be avoided. In our large-area field beds for growing orchids, bricks are laid around the perimeter and moss is planted on top. Bricks and moss have a strong capacity to absorb water and retain moisture, and 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 method.
In the classification of xerophytes, hydrophytes and mesophytes, orchids belong to the 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 rhizomes. The pseudobulbs of orchids are fat and swollen, with a cuticle on the surface, while the epidermal cells are thickened to form stone cells, and the stem is filled with vascular bundles. The pseudobulbs can store nutrients and water and do not easily lose them by evaporation. Orchid roots are mostly fleshy, with the outermost layer being velamen tissue, whose cells are elongated tubular or polygonal. When the velamen tissue cells mature, the protoplasm disintegrates and thickened striations form 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 from within 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 places of origin of orchids, orchids mostly grow on hillsides, on both sides of ridges, and in rock crevices. These places drain well and are free from the harm of accumulated moisture and waterlogging. It is precisely by adapting to such an environment that the rhizome structure of orchids is suited to storing and conserving 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 need not be watered too much. In addition, those with thick cuticles on the leaves should be watered less; for example, the leaves of Tiegusu have a thick cuticle and lose little water through evaporation, so watering must be strictly controlled.
(2) The growing season of the orchid.
In spring, as temperatures gradually rise, 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. During this period, lack of water will delay flowering and make shoots weak. In summer, temperatures are high and water evaporation is great; this is the period of leaf expansion, root emergence and elongation of roots and leaves, so water once each morning, and in the evening if the potting soil is dry, add some water to moisten the potting soil, thoroughly moisten the leaves, lower the temperature and reduce nutrient consumption, so as to favor growth and development. Entering autumn, temperatures gradually drop and orchids grow slowly; observe the dryness or moisture of the potting soil each day, watering when dry and leaving it alone when moist. In winter, orchids enter dormancy. The potting soil should be somewhat dry, and watering should be reduced or omitted, but attention must be paid to the potting soil to prevent it from losing so much water that it instead draws water out of the roots. At the turn of winter and spring, after Cymbidium goeringii forms 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 cold damage.
(3) The growth condition of the orchid.
Orchids with strong growth and good roots can be watered more; otherwise reduce watering as appropriate, and diseased plants should have their water even more strictly controlled. When orchids are sprouting and growing, water can be somewhat more; after sprouting, it can be gradually reduced. When new shoots gradually mature, water should again be somewhat less; when flower buds appear, slightly more water; and during flowering, water should not be excessive, so as to prolong the flowering period. After the flowers fade, watering should be stopped for several days to let the potting soil dry slightly and the orchid rest briefly, and then watering can resume.
(4) The condition of the pot and the plant.
That is, water according to the material and size of the pot: clay pots and large pots can be watered more, while porcelain pots and glazed pots should be watered less. When many plants are potted or field-grown orchid plants are dense, water more.
(5) The dryness or moisture of the potting soil.
The bases for watering, such as season, plant condition, weather, pot and soil quality, can all be comprehensively reflected in the degree of dryness or moisture of the potting soil, so the dryness or moisture 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, its color becomes lighter, and the moss on the pot surface is dry and wilting, this indicates that the soil is dry. Water immediately. If the potting soil is dark in color, has a damp feel, and the moss is moldy, this indicates that the soil is too wet and should not be watered. Generally, a soil water content of 15%-20% is suitable.
(6) Watering time.
Generally speaking, in spring and autumn it is best to water in the morning; during the hot midsummer period it is best around sunrise and around sunset; in early winter and early spring, water after the sun has risen overhead and the temperature has warmed slightly. During the period when plants 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 seep into the leaf sheaths. Among the folk 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 water requirements at each stage of growth and development, and management should be adapted to local conditions and handled flexibly. Generally, after the Beginning of Spring, the climate gradually warms, the flower buds swell, and the soil should be kept moist, with misting once every 2-5 days. After Awakening of Insects, for flowerless Cymbidium goeringii and Cymbidium faberi grown in the open, the pot water dries easily under wind and sun, so routine 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 brief dormant period, grow slowly and lose less water through the leaves. From June onward, the weather gradually becomes hot and the young shoots (that is, young buds) grow faster; at this time pay more attention to soil moisture and frequently spray the orchid leaves and benches with clean water to create a humid microclimate, which is favorable for the young shoots to elongate and put out leaves. During the plum rain season, watering should be controlled to reduce the occurrence of disease; leaf-variegated plants and some petal-type seedlings are even more prone to disease and should be watched especially closely. During the dog days, the climate is hot, so in addition to strengthening shading, carefully maintain soil moisture and spray the leaves and pot surface with clean water around sunrise every day. After White Dew, it gradually turns cool in autumn, and with the moisture of night dew, the growth of new plants stalls and the 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 until moist. In late autumn, the new plants have changed from fresh green and tender green to deeper, darker colors. The flower buds and their sheaths are all visible, so guard against prolonged rain and excessive moisture to reduce rot of the sheaths (that is, rot of the bud sheaths), and try to shelter them from rain and expose them to 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 the least suitable for orchids. If tap water must be used, it should be stored in a reservoir for more than 24 hours, and better still exposed to sunlight, and after the disinfectants in it have settled out or decomposed, use the clear water on top to water the orchids. In addition to this storage treatment, there is also an activation treatment, which is to keep fish, algae, chlorella, red floating algae and other aquatic organisms in the reservoir where tap water is stored, in order to improve water quality. But be careful whether the fish have diseases, to prevent contamination of the water quality. 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 the hot summer, after the 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 disrupt 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 is close to the soil temperature. It is best to bury the storage pond or storage jar half in the soil and add shade, so that the water temperature does not become too high in summer.
(8) Watering methods.
Common orchid watering methods include pouring, misting and soaking. Usually a watering can, ladle or hose is used to water; when watering, pour slowly from the edge of the pot so that the water gradually seeps downward and toward the center, and never pour it suddenly into the center of the leaf cluster, nor let the water splash up the potting soil and dirty the leaves. Misting should soak through the whole pot, not just half of it, that is, with water only in the surface layer while the lower layer gets none; if half-watering is done for a long time, the surface will be wet while the interior is dry, causing some orchid roots to be unable to absorb water for a long time and shrivel, while the upper orchid roots turn upward and grow, sprawling and curling in the surface soil. Many people, for convenience, attach a rubber hose directly to the tap and irrigate the orchid pots, which 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 misting method is to spray water on the leaf surface with a spray can, which can both increase air humidity and soil moisture and wash away dirt on the leaf surface; this method is often used during the orchid growing season. Do not mist too much each time; the standard is that the leaf surface is wet but water does not run off. If too much water is poured into the heart of the leaf and remains there for a long time, it will rot the new shoots. The nozzle holes of the spray can should be fine and dense, and the water droplets fine and even. The soaking method, also called seeping, is to place the bottom of the orchid pot in 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 water tray; the pot absorbs the accumulated water in the tray and then moistens the potting soil, which can maintain relatively stable soil moisture. The disadvantage is that the bottom hole of the pot is blocked by water, so 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 of more than 14 hours is long-day, and less than 14 hours is short-day. Among plants, those that need long days to flower are called long-day plants; conversely, those that need short days to flower are called short-day plants. Light and sunshine are closely related to the growth and development of orchids.
Orchids' requirements for light:
There is a floral proverb: shade for camellias, sun for peonies, half shade and half sun for the four-season orchid. This shows that different flowers and trees have different demands for sunshine, 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 turns pale green; if suddenly exposed to strong light, the leaf color quickly turns yellow, the leaf surface becomes rough, and the leaves may even scorch. With moderate light, the leaves are green with a fine texture and luster; with too little light, the leaf color is dark green and loses luster. The effect of light on sprouting - the intensity of light has a direct influence on the number of leaf buds and flower buds, the time they emerge from the soil, and their growth condition. With too little light, orchids produce many leaf buds and few flower buds, and their 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 flowers. The effect of light on flower color and flowering - the flower color of orchids is mainly determined by flower pigments, and the violet light and ultraviolet light in light are the main light energy that forms orchid pigments. Therefore, when light is strong, the flower color is deeper and more brilliant; when light is extremely weak, the flower color is very pale, and compared with normal plants it may be mistaken for another variety. For example, in ancient times in Ningbo, Zhejiang, there was a kind of Snow Orchid, produced on the shady back side of mountains; if planted in a pot and exposed to a little sun, it would turn green, and so it was regarded as rare and precious, yet today it is often encountered during wild collection, and artificial cultivation can also obtain it. Some people use this to commit fraud and pass it off as a new variety, and those with insufficient experience are often deceived. If other conditions are the same, the orchid pot placed in a position with stronger light will bloom first; this is because the accumulated illumination and accumulated temperature first reach certain values. Some people have experimented and found that extending the light period to 14-16 hours can promote earlier flowering in medium-sized 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 plus low temperatures must be provided to promote flowering. For orchids that bloom in summer, long days and short nights plus high temperatures are required to promote flowering. For orchids with flower buds, to promote earlier flowering, appropriately extend light and increase temperature. In a small room, using a 100-watt bulb can raise the room temperature by 3°C-5°C and can promote earlier flowering. The relationship between light and leaf variegation - leaf variegation is the cultivation technique in which lines or spots appear on the leaves. Leaf variegation is related to light. Changes in light can be used to promote changes in leaf variegation. The method is to use robust growing orchid seedlings, with more than three plants connected together, and in summer before 9 o'clock, in winter before 10 o'clock, place the orchid pot in sunlight, insert a thermometer into the pot, and when it has been exposed to 30°C, move it into the shade. When the temperature drops to 25°C, move it out into the sunlight again. Repeat this over a long period. Alternating shade and sun, cold and heat, is favorable for 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 variegation 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 species, but there are also differences among species. Species that bloom in spring, such as Cymbidium goeringii, Cymbidium tortisepalum and Songchun, need relatively weaker light, and the shading degree should be controlled between 70%-80%. Species that bloom in summer and autumn, such as Xiahui and Qiusu, need somewhat stronger light, and their shading degree should be controlled between 60%-70%; Cymbidium sinense needs about 85%. The light duration and intensity of spring, summer, autumn and winter are all different, so they should be treated separately and the shading degree adjusted well. Within a single day, morning and evening sunlight can be allowed, while the strong midday sun must be blocked and regulated, and on cloudy days the shading degree should be reduced. It is worth noting that after a summer rainstorm, or when it first clears after long rain, orchid pots must absolutely not be exposed to the sun; the experience of predecessors is: if exposed immediately after rain, the water in the pot heats up and scalds the leaves and injures the roots. Although orchids are relatively shade-tolerant, they also have phototropism, and in the same cultivation site, the flowers and leaves on the sunny side are always somewhat more luxuriant. Over a long time this makes the growth of flowers and leaves uneven, and they lean to one side. For symmetry and beauty, the direction of the orchid pot should be rotated and adjusted at intervals. If there is a special need for shaping or composition, in order to express a particular poetic and pictorial mood, the position of the light source can also be used to strengthen the inclination of flowers and leaves, achieving the beauty of dynamic balance and satisfying 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, and use the light-transmitting and sun-shading properties of such buildings to regulate light. As long as the orchid pots are placed appropriately, the desired effect can be achieved; bamboo blinds or shade nets can be hung on the sunny sides of these buildings for regulation. For potted orchids grown on balconies, light is regulated by carrying them in and out; although laborious, it also cultivates enjoyment, and there is pleasure in combining flower growing with fitness. Building frames - shade frames can be built with bamboo, wood, angle steel and the like, covered with bamboo blinds, plastic film, shade nets, etc. Our method of regulating light intensity is to use bamboo to build frames in the orchid nursery, on which are set two layers of shade net with a shading rate of 50%-70%; 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 two layers, in spring and autumn use one layer; on clear summer and autumn days at noon use two layers, on cloudy and rainy days one layer. In winter, decide according to conditions: on clear days let 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 it is too great, temperature and humidity will also change accordingly, which is unfavorable for orchid dormancy. In addition, before orchid flower buds are ready to open, they must have moderate diffuse sunlight, otherwise the flower color will be dull and not show its beauty. Building trellises - on the orchid cultivation site, build bamboo, wooden or reinforced concrete trellises and let vines such as grapes, honeysuckle, morning glory, Chinese trumpet creeper and cypress vine climb and spread over them; this both shades and is beautiful and practical. Deciduous vines shade in summer and let light through in winter, which is a natural regulation. Planting trees - around the orchid nursery, plant evergreen trees, deciduous trees, bamboos and the like of different heights in matching arrangements to regulate light intensity.7. Fertilizing. Orchid roots have no fibrous roots, and within the roots there are symbiotic fungi.
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 and coexisting symbiotic relationship. But a stable balance must be maintained between them for luxuriant growth. Preparing suitable nutrient soil and fertilizing appropriately to maintain the balance between the two can promote robust orchid growth. Previously some people thought that since orchids grow in the mountains and are by nature elegant and pure, clear water and fresh air would be enough. Others loved orchids too deeply and were too impatient, often applying strong, highly concentrated heavy fertilizer, producing results contrary to their wishes. Therefore we must seriously explore scientific and rational fertilization.
(1) Types of fertilizer.
Fertilizers can be distinguished by their effective components, their nature and their method of use. By effective components, there are mainly nitrogen, phosphorus and potassium fertilizers. Nitrogen is a major component of cell nuclei and proteins, and an indispensable element in forming chlorophyll. Nitrogen fertilizer can make orchid leaves luxuriant and robust; without it, leaves droop and soften, sprouting is difficult and the propagation rate is low. Commonly used nitrogen fertilizers include compost, human and animal urine and manure, urea, green manure, ammonium sulfate, ammonium nitrate and so on. Phosphorus is also a major component of cell nuclei and directly affects cell division, chlorophyll formation and protein synthesis and transformation within plant cells; it can promote flower bud differentiation and growth and bring about larger flowers, brighter color and stronger fragrance. Commonly used phosphorus fertilizers include superphosphate, monopotassium phosphate, phosphate rock powder, bone meal, rice-washing water and so on. Potassium directly participates in photosynthesis, can normalize cell physiology, and is also related to the synthesis of carbohydrates, proteins and fats. Potassium fertilizer can make orchid stems, leaves and roots grow robustly, make leaves tough and not easily broken, enhance cold resistance and disease resistance, and also increase flower fragrance. Commonly used potassium fertilizers include plant ash, potassium sulfate and monopotassium phosphate, all of which are fertilizers relatively rich in potassium. Besides the three main elements nitrogen, phosphorus and potassium, orchids also need various trace elements such as calcium, magnesium, iron, boron and zinc, which can be satisfied in the prepared culture soil and generally need not be added separately. But the demand for nitrogen, phosphorus and potassium is relatively large and must be addressed through fertilization, repotting and soil changing. By the nature of the fertilizer, it 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 the soil well aerated and water-retentive, and its fertilizer effect is long-lasting, continuously decomposing long-acting nutrients for orchids to absorb. Inorganic fertilizer, also called chemical fertilizer, has a high nutrient content, is clean and odorless, and can be diluted and used immediately without fermentation; it is convenient and quick-acting, but its effect is short-lived, 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 chemical fertilizer is used in combination, the effect is still very good. By method of use, fertilizers can be divided into base fertilizer and top dressing. Base fertilizer is fertilizer added to the soil when preparing culture soil or before planting, such as leaf mold, grass compost and chaff soil, which are both the substrate for growing orchids and base fertilizer. Silkworm droppings, human manure, cow dung, bone meal, hair and cake fertilizer can all be used as base fertilizer added to the bottom of the pot or turned under the soil as base fertilizer, but chicken manure and night soil should be avoided.
(2) Top dressing is fertilizer applied during the growing season after orchids have been planted.
Generally orchids are repotted and the soil changed only after 2-3 years of planting, and nutrients must be supplemented in the interim, so top dressing 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. If it is a leaf-variegated variety, then apply less nitrogen fertilizer or none at all, because dark green leaf color will affect the appreciation of the leaf variegation. When the summer temperature is above 30°C, do not fertilize, 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 fertilizing too frequently in summer, it easily forces out 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. When the temperature is below 10°C, do not fertilize, because at this time the plant is in a semi-dormant state and does not absorb nutrients. Only when sunlight and temperature are suitable and photosynthesis is vigorous should fertilizer be applied. In winter orchids are dormant, so there is even less need to fertilize. Before orchid new shoots grow from the pseudobulb to half maturity, and around the time the leaf buds emerge from the soil and during their elongation period, this is the vegetative growth stage of orchids, when somewhat more nitrogen fertilizer should be applied and phosphorus and potassium fertilizer should be less. After vegetative growth comes reproductive growth; the nutrients produced by photosynthesis are stored in the pseudobulbs and leaves for use in flowering or new shoot growth. At this time more phosphorus and potassium fertilizer is needed, and 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 lack of fertilizer, and top dressing should be applied in time. But sometimes leaves also turn yellow due to too strong sunlight. Diseased plants should not be fertilized; wait until the disease is cured and the plant has recovered before fertilizing. Robust orchid seedlings can be helped by applying more fertilizer.
Ancient orchid growers had this 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, for it cannot absorb it and it will be harmful. For orchids that are regularly fertilized, one also cannot go a long time without fertilizing. In short, uneven fatness and thinness is of no benefit to orchids. Usually Cymbidium goeringii, Cymbidium faberi and Cymbidium ensifolium begin to be fertilized in early May. In the dog days of summer, and from December to early February of the following year, no fertilizer is applied. From May onward, apply dilute fertilizer once every 2-3 weeks until the end of September. In early September apply dilute fertilizer once to Cymbidium goeringii, and in late September fertilize Cymbidium ensifolium once. After each fertilizing, clean water must be added the next morning, which facilitates absorption by the orchid and also prevents harm to orchid roots from improper concentration. Generally, fertilizing is not suitable before and after flowering.
(3) Fertilizing methods.
Fertilizing must mainly use organic fertilizer, which can make the soil loose and well structured and is favorable for orchid growth. Also, apply thin fertilizer frequently; that is, the experience of predecessors was that it is best to apply frequently and dilute, and one must absolutely avoid sudden heavy applications, which is what people today mean by small amounts and many meals. When applying, dilute the water-and-fertilizer mixture appropriately, then use a watering can to pour it around the roots, without contaminating 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‰ monopotassium phosphate can be used as top dressing 2-3 times.
8. Ventilation.
Ventilation is also very important in orchid cultivation and management, yet it is often overlooked by people. 146 Zhuhongxinsu (Beijing). Good ventilation continuously supplies orchids with ample fresh air, can promote photosynthesis, increase nutrient production, promote metabolism and make orchids luxuriant. 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 high, the flower benches should not be too low, and attention should always be paid to ventilation. Orchids like gentle and soft breezes and do not like sharp winds, and excessively cold or 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 so that wind does not cause leaves to rub against each other and be damaged. If the site is small, the flower benches can be built in stepped form, which is good for ventilation and convenient for management and viewing. Each orchid pot should not contain too many or too densely packed plants. If the plants have multiplied too densely, they should be repotted and divided in time. Frequently clear weeds, diseased leaves, fallen tree leaves and other debris from the orchid pots to facilitate ventilation within the pot. Routine work for field-grown orchids through the four seasons: in spring, around Qingming, remove the plastic film from the large shed, then water thoroughly once; several days later apply once a 15-20 times diluted duck feather water or fertilizer water made by fermenting 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 sum it up in two words: autumn tempering. That is, after the beginning of autumn, orchids are no longer fertilized, water is controlled and light is increased, to urge early maturity. Generally, potted orchids should follow the golden rules of orchid growing: not out in spring, not in the sun in summer, not dry in autumn, not wet in winter. But field-grown orchids are not exactly like this; in autumn they should be dry rather than wet. The reason is: although the air is dry in autumn, ground moisture still rises from 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 tempering can promote the concentration of nutrients into the pseudobulbs, increase the protoplasm concentration of the pseudobulbs and lower the freezing point, so that they will not suffer cold damage. If orchid seedlings grow vigorously in autumn, then when a cold wave comes and the temperature drops sharply, they will certainly suffer cold damage. Field-grown orchids cannot be moved indoors before the severe winter arrives, so only through autumn tempering can they survive. November is a relatively busy season in the orchid nursery, and the main work is to prepare for the orchids' overwintering. First, remove the upper layer of shade net, then install the plastic greenhouse; the two ends of the greenhouse are not closed at first, and are closed only when the temperature drops markedly, and on clear days they are opened at noon for ventilation. This month, spray once with 1:1 Bordeaux mixture. Entering the severe winter season, first, one must not water casually, and second, moderately increase light. "Moderately" 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 net should be put down so that the temperature in the shed does not rise or fall abruptly. If the shade net is not put down and the temperature in the shed reaches 18°C-22°C for several consecutive days, some new shoots will begin to sprout, and once a cold wave arrives and the temperature drops sharply, they will certainly be frostbitten. Therefore, in winter a dormant environment must be created for orchids, and dormancy must not be broken casually. 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 through the winter are very likely to wither and yellow. Light should be gradually and moderately increased, and the plastic film must not be removed too early; only after the weather in early April has settled clear can it be removed.
1. Potting soil requirements: it is best to use neutral to slightly acidic soil containing large amounts of 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 grow orchids.
2. Placement site: in spring, summer and autumn, orchids can be grown outdoors and on balconies, and a place with good ventilation, moist air and no environmental pollution should be chosen. Being near a pond or river is of course good, but at least there should be trees or bamboo groves and shade nets to reduce sunlight and lower temperature. Orchid pots are best placed on wooden frames (or steel frames); if placed on the ground, bricks should be used as a base. In home balconies, a small galvanized sheet water basin can also be used to store water with bricks placed on top for growing, to increase humidity.
3. Appropriate shading: most orchids belong to semi-shade plants, and most species fear direct sunlight and need appropriate shading. In early to mid-April, orchids can have the nets removed and windows opened, and be exposed to more sunlight to promote growth. In May, apart from the midday sun, they can receive 6 hours of sunlight; from June onward, shade all day; after October, apart from the midday sun, they can be kept fully open. Remember the proverb: "More shade, better leaves; more sun, better flowers."
4. Reasonable fertilizing: orchids are by nature "vegetarian," and fertilizing should depend on the chosen potting soil and growth condition. 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 must wait 1-2 years before fertilizing. Generally, in June-July, when orchid leaf buds have elongated to about 1.5 cm, apply a decomposed liquid fertilizer once every three weeks (a dilute concentration of about 10% is suitable). Avoid chemical fertilizers. In high-temperature seasons, fertilizing is not suitable; in August-September apply a diluted liquid fertilizer once every two to three weeks. Each time orchids are fertilized, it is best to do so in the evening, and in the morning water with clean water, which is called "return water."
5. Appropriate 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. Water more when there are many leaves, less when the leaves are fine. In April-May, when new shoots have not yet emerged from the soil, the potting soil should be somewhat dry, because if too wet the new shoots easily rot; from June to September is the growing period of orchid new shoots, and the amount of watering should be increased, watering once each morning on clear days or once a day, and absolutely avoid watering under the blazing midday sun. In autumn, reduce the amount of water as appropriate; leaf-surface misting can be used, and it is best to keep the potting soil moist. In winter, water should be even more controlled, and it is suitable to maintain "80% dry, 20% moist."
6. Evening misting: orchids originally grow in an environment with moist air, so in dry seasons, in addition to shading, evening misting is also necessary to increase air humidity and lower temperature; water can also be poured on the ground (bench surface) where the potted orchids are, and "one cold and one hot" can further stimulate orchid growth.
7. Wind and rain protection: the "February ghost wind" causing old leaves to yellow and fall is a normal phenomenon, and dead branches and withered leaves can be cut away. Orchids can be exposed to light rain, but must avoid moldy rain, rainstorms or continuous rain, otherwise the heart and leaves easily rot. In rainy seasons, a small amount of plant ash can be sprinkled appropriately.
8. Pruning and flower removal: during orchid cultivation, withered, yellowed and broken leaves and diseased leaves should be cut away frequently, to facilitate ventilation. For precious orchids, if there are too many flower buds, keep only the strong buds, and 1-2 flower buds per pot is suitable. For Cymbidium goeringii, remove the flowers half a month after they open; for precious orchids, they should be removed after 7 days, so that the spring leaf buds grow robustly and produce better growth 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 and their places of origin vary, their cold resistance also differs, so the time for bringing them indoors in winter and the position for placing them indoors also differ. Cymbidium kanran, autumn orchids and Cymbidium sinense grow in the south and should be brought indoors (or have windows closed and nets drawn) when the temperature is 5°C, and placed as far as possible in a sunny spot facing south. Spring and summer orchids have stronger cold resistance and can be brought indoors only when the temperature reaches 0°C, and placed facing northeast. Around noon on clear, windless days, windows facing south or southeast should be opened and nets drawn for ventilation. Autumn orchids must not have windows opened on clear days at 1-2°C. Of course, if there is a greenhouse, electric light heating can be used.
10. Disease and pest control: potting soil should generally be sterilized (exposure to the blazing 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 away with a damp cloth, and when there are many pots, 500-800 times Bordeaux mixture or thiophanate can be used, sprayed once every 7-10 days. Among pests, scale insects (commonly called "orchid lice") occur most; during the hatching period, use 1% omethoate and 25% phosmet emulsifiable concentrate at 1000 times solution, spraying once a week. To treat the symptoms one must treat the root cause: pots should be spaced appropriately, placed at different heights, with increased air circulation and ventilation, to reduce the occurrence of disease.
However, different orchids have different cultivation methods.
Several aspects needing attention in orchid cultivation
Our country has a long history of orchid growing, and our predecessors accumulated rich experience in orchid cultivation 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, and has developed the growth habits of liking half shade and half sun and liking moisture and airy conditions. As long as the growth patterns of orchids are grasped and conditions close to the orchids' growing environment are provided or created, all parts of the country are suitable for growing Cymbidium goeringii and Cymbidium faberi.
2. Use of growing medium. According to cultivation experience in various places, as long as it is slightly acidic, any growing medium (including soilless culture) can grow orchids well; the issue is that different growing media should be managed by different methods. For flower pots, it is best to use clay pots or Yixing clay pots, because orchids are aerial-root plants and pot breathability is very favorable for 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 holds sufficient water, and granular soil plus volcanic rock 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 the growing medium about one centimeter deep has turned white. To increase air temperature, the pot surface can be misted to increase the moisture of the growing medium in the upper part of the pot so that the orchid plant and pseudobulbs maintain a certain moisture, and when the whole pot from top to bottom has not yet dried completely, water heavily again, thoroughly.
4. Fertilizing: on the basis of mastering watering well, in order to promote better growth of the orchid plant, fertilizing becomes even more important; organic fertilizer, that is, farmyard manure, should be dilute and can be applied once every ten or more days, while other inorganic fertilizers (chemical fertilizers) should be used according to the instructions. During the orchid growing season, 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 if the fertilizer does not contact the orchid roots, but too much fertilizer easily burns orchid roots and causes black spots; if fertilizing is done properly, it can produce strong seedlings and good flowers. The overall requirement for fertilizing orchids is a small amount, clear and dilute, truly achieving thin fertilizer applied frequently.
5. Pest and disease control: insect pests are easy to prevent, but fungal diseases are difficult to cure. If scale insects and other pests are found on orchid plants, spray with omethoate or decamethrin according to the instructions, and it is best to use them in combination, 2-4 times a year. General fungal diseases such as black spot can also be treated; use fungicides such as copper hydroxide, thiophanate-methyl and chlorothalonil according to the instructions, and during the growing season carry out regular alternating treatment and preventive spraying every 15-20 days. If "Bailashi" soft rot (rot coccus disease) is found, it is an incurable disease among orchids and cannot be cured at all; once found, remove it promptly. Therefore, when purchasing orchid plants, be sure to pay attention and absolutely do not buy lower-priced diseased plants and bring them home, thereby affecting other precious orchid plants.
Different orchid species have different temperature requirements. The most suitable temperature for vegetative growth of Chinese orchids is 20-30°C, the adaptable temperature is 5-35°C, and the temperature for the reproductive period is generally between 5-15°C. Night temperatures are 3-5°C lower than daytime. When the summer temperature is above 30°C, the higher the temperature, the more orchid growth is inhibited. But Chinese orchids under ventilated conditions can tolerate short periods of high temperature up to 35-42°C without harm. 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 relatively cool, with temperatures generally not exceeding 20°C, and winter temperatures do not fall below 10°C. Cymbidium kanran and Cymbidium ensifolium originally grow in mountain forests transitional to the subtropics. Cymbidium goeringii and Cymbidium faberi mostly grow in temperate mountain forests; in temperate regions, summer temperatures reach about 38°C, but in shaded mountain forests daytime temperatures do not exceed 30°C, and at night are about 18°C. In winter, under short-term snow cover, the surface temperature is still above 5°C and has no effect on flowering. Indoors they can also overwinter at about 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, and the reproductive growth temperature is 8-18°C. The temperature requirements for Cymbidium lianpan are 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 by the sun." This sentence highly summarizes the enormous role of light in the growth, development and continuation of generations of living things, especially plants. The orchid plant itself relies on the photosynthesis of green leaves to obtain energy to maintain and continue life and reproduce, and sunlight is the driving force of orchid life. But for orchids, which require half-shade and half-sun habits, excessively strong light will also harm orchid growth; one must regulate and control light suitable for orchids according to temperature, humidity and the growth habits formed under the ecological environments of various orchids in different seasons, so as to satisfy and benefit the survival and growth of orchids. Below, in connection with the close relationship between light and orchid plants, I will discuss some immature views and explore them with fellow orchid growers, perhaps they 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 effect of light on 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 the effect of light 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 halves, photosynthetic intensity also doubles or halves. 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 pseudobulbs and roots digest and decompose at night, converting carbon dioxide into sugar and then into various needed proteins, which are transported to all parts of the plant by 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, will cause leaves to become dwarfed and yellowed, and even age prematurely without growing, gradually declining and dying; conversely, if light is insufficient, although the plant still grows, the nutrients produced are not enough, which is likewise unfavorable for 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: for sun plants, rational close planting, controlling population development, and ensuring the plants have enough light; if natural light is insufficient, increase artificial light; for shade plants, pay attention to moderately shading while satisfying their photosynthetic intensity as much as possible. Letting orchids have relatively abundant light of sufficient duration is beneficial.
② "Light quality." When regulating light, one must 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. The leaves of orchids, however, respond only to red, orange, yellow and blue-violet series of light. The different colors of sunlight produce differences in the intensity of plant photosynthesis; red light and blue-violet light have higher efficiency, 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, which manifests in plants as thickening; far-infrared light irradiation is beneficial to cell elongation, which manifests in plants as growing taller; ultraviolet light irradiation is beneficial to shortening the internodes of orchids, which manifests in plants as dwarfing. Therefore, supplemental lighting for orchids should set different light qualities according to the specific growth conditions and requirements of orchid seedlings. (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 portion of xenon lamps approximates sunlight, but their ultraviolet and infrared light exceed that of the sun.) Orchid cultivation generally uses mostly red light and blue-violet light. Experts recommend that supplemental lighting for Chinese orchid cultivation should use more red light. Of course, if conditions permit, choosing a plant lamp designed specifically for orchid supplemental lighting is even better.
In short, one should comprehensively consider and make up for deficiencies based on the types of photosynthetic products needed as described above, select a suitable light source, and promote the normal growth of orchids.
II. The effects of light on orchid leaves, buds and flowers:
1. The effects 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; they prefer scattered light and dislike direct strong light. When light is too strong, orchid leaves tend to be shorter, thicker and stiffer, with a rough leaf surface, and the leaf color turns pale green. If suddenly exposed to strong light, the leaf color rapidly turns yellow, the leaf surface becomes rough, and the leaves may even scorch. With moderate light, the leaves are green with a fine texture and luster, and grow robustly. When 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. Both excessive and insufficient light will affect the perfect growth of orchids.
② Changes in light can promote the manifestation of leaf variegation. Plants with the potential for variegation can receive a somewhat longer light duration; for variegated orchids, sunlight from 6 to 9 in the morning is best. Someone conducted an experiment as follows: before 9 o'clock in summer and before 10 o'clock in winter, place the orchid pot in the sun, insert a thermometer into the pot, and when it reaches 30°C move it into shade. When it drops to 25°C, move it out into the sunlight again. Repeat this over the long term. One shade and one sun, one cold and one hot, is beneficial to the emergence of variable factors within the leaves; over the years, variegated leaves may appear. However, this must be premised on the existence of recessive variegation factors within the orchid leaves; the variation of sunlight merely promotes their manifestation, with no inevitable connection. White-spotted cells are the decisive factor and play the determining role in changes of orchid variegation.
2. The effects of light on sprouting. Light can raise the sprouting rate of orchids. Orchid sprouting cannot rely solely on water and fertilizer management; appropriately increasing light is crucial. The sprouting rate is generally high when receiving strong sunlight; strengthening light can not only increase the sprouting rate but also make new shoots more robust.
① Orchids planted shallowly sprout more. Orchid growers generally believe that "deep planting is not as good as shallow planting" for orchids. This is because when orchids are planted deep, the pseudobulbs are buried deep and receive little light; under the same fertilizer, water and management conditions, deeply buried pseudobulbs are small and sprout less in spring. When planted shallowly (with half the pseudobulb exposed above the soil), the pseudobulbs are large and sprout more in spring. This is closely related to the light spectrum and the length of light duration. It also demonstrates the reasoning behind why light can raise the sprouting rate of orchids.
② Light can promote flower bud differentiation, achieving the goal of more blooming. This is because light is the source of nutrients for flower bud differentiation and growth. The intensity of light has a direct influence on the number of leaf buds and flower buds, their emergence period and their growth condition. Orchids with sufficient light produce more nutrients through photosynthesis, have more flower bud differentiation, bloom more, have deeper flower colors, and have large, fine flower shapes. Conversely, orchids under too weak light may grow lushly, but the nutrients produced are insufficient, so more leaf buds and fewer flower buds grow. Even if they bloom, the flower color is pale, the flower shape is poorer, and the growth condition is poor. Therefore, appropriately increasing light for a period before flower bud formation can promote flower bud differentiation and achieve the goal of more blooming.
3. The effects of light on flowering:
① Light intensity 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 primordial light. Violet light and ultraviolet light in the light spectrum are the main light energy that forms orchid pigments. Therefore, sunlight has a direct influence on the colored flowers of orchids. Strong light makes flower colors deeper and more vivid; excessively weak light makes flower colors extremely pale. For example, to make the flower color of the red-flowered series beautiful, sunlight can be slightly strengthened; to make the blue-green series 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 favor the sun to thicken the petals. When cultivating colored flowers, paying attention to and controlling light during cultivation can make the flower color more beautiful. Green and white flowers need reduced light; red, yellow, pink and purple flowers need increased light. For example, Cymbidium goeringii blooming in shade has better flower quality and color than those blooming in sun (except colored flowers), and the flower stalks are also longer. For Cymbidium faberi and Cymbidium ensifolium, stronger light is beneficial to flowering, producing large flowers with good color and fragrance. Therefore, controlling and regulating reasonable light is a maintenance technique that must be mastered to fully express the best flower color.
② The effects of light on orchid blooming.
For orchids with flower buds, promoting early or delayed flowering can be achieved by regulating the length of the light period. Appropriately extending light and increasing temperature, such as using a 100-watt bulb or infrared lamp in a small room to raise room temperature by 3°C-5°C, can promote earlier flowering. Similarly, orchids with flower buds placed in a location with weak light and low temperature can also delay flowering. For orchids that have already formed flower buds, appropriately extending sunlight and raising temperature, or using a 100-watt 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 blooming. 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. Utilizing this biological characteristic, some have experimented with extending the light period to 14-16 hours, which can promote early flowering of medium-sized plants and small seedlings; but for mature orchid plants, a light period of no more than 8 hours is sufficient to promote flowering. Appropriately regulating light intensity can make orchids bloom at the right time. Especially for species that bloom in spring, flower buds are generally already formed by July-September of the previous year; after they pass through the winter dormancy stage, appropriately increasing light and raising temperature can promote early flowering to catch the Spring Festival. Conversely, appropriately reducing light and lowering temperature can also delay flowering to coincide with orchid shows. In short, regulating light intensity can make orchids bloom at the right time.
III. The effects of light on orchid fertilization and sterilization.
1. The relationship between light and fertilization. Generally, how to shade and supplement light for various orchids in different seasons and at each growth stage so that orchids receive suitable light intensity is a matter of common concern. However, in the process of orchid cultivation, how to correctly handle the relationship between fertilization and light may not necessarily be taken seriously, yet this is equally important for the vegetative growth of orchids. The strong or weak light will lead to strong or weak assimilation. If light is too weak, the assimilation of leaves will also be insufficient. This leads to poor digestion of nitrogen fertilizer during the day, less accumulation of sugars and starch, and therefore less decrease at night. Over time, the leaves will become very long while the roots remain very short. If light is too strong, the assimilation of leaves will also be too strong. Orchid 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 various; light is not the only factor (for example, long-term dryness of the orchid pot, excessive amino acid fertilizer, high-carbon growth, small day-night temperature difference, nitrogen deficiency and other conditions can also produce these problems). However, failing to correctly handle the relationship between fertilization and light is also one of the important reasons, and must be given attention. The maintenance measures for such situations 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 a phenomenon of "small leaves and strong roots," light should be reduced and sufficient inorganic nitrogen continuously supplied. This can both reduce sugar content and promote protein synthesis, and the new growths will return to normal.
Practice has proven that only under conditions of sufficient light can orchids absorb nutrients. Therefore, when fertilizing orchids, there must be moderate sunlight; the best time to fertilize is on a morning with good weather. When applying chemical fertilizer, the light intensity should be relatively higher; when applying organic fertilizer, it should be relatively lower.
2. Sunlight is a good weapon for sterilizing orchids and preventing disease. Light can not only raise temperature; the ultraviolet rays in the spectrum can kill and prevent the breeding of fungi, pathogens and viruses. Pathogenic bacteria generally find it very difficult to survive under blazing sun exposure. Therefore, through sun exposure, pots and planting materials can be sterilized and disinfected. However, for the sterilization and disinfection of orchids, the use of sunlight must be timed. For example, in winter, sun the orchids and let the whole plant bathe in ample sunlight; in summer, avoid the midday and west-facing blazing sun. Light can also close the stomata of orchid leaves, blocking 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 in an open state, are susceptible to infection by invading pathogens; orchid plants with insufficient light are prone to pests and diseases. Using sunlight for sterilization and disinfection has always been advocated by orchid growers. Orchid photosynthesis, like other biochemical processes, cannot exist in isolation, and at the same time is constrained and influenced by external environmental conditions. These external factors are: light intensity, carbon dioxide and oxygen concentrations, wind speed, temperature, water supply, inorganic nutrients, and pollutants in the atmosphere and soil, etc. 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 the above internal and external factors, the goal of raising the efficiency of plant photosynthesis can be achieved. This promotes the healthy development, growth and flowering of orchids. In summary, according to the growth habits of orchids, giving appropriate light can improve fertilization efficiency, enhance disease resistance, and benefit the healthy growth of orchids. For this reason, orchid plants that are weak, do not bloom and are prone to pests and diseases must have strengthened light.
IV. The light intensity for orchids.
1. Orchids grow in mountain forest areas, and the ecological environment has fostered a need for half-shade and half-sun light conditions. There is a folk flower saying: "Shade for camellias, sun for peonies, half-shade and half-sun for Four Seasons 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 orchids are not entirely the same. Due to differences in ecological environments, various orchids differ in their light requirements, strong or weak. 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 making the leaves scorch yellow and wither; at this time shading is necessary, blocking 70%-80% of sunlight. Cymbidium kanran and Cymbidium sinense relatively need less light, and in summer should block 80%-85% of sunlight. For newly potted plants, diseased and weak seedlings, old plants, particularly delicate plants, and plants that have not been hardened and have long been in half-shade and half-sun, shading must be provided during the growing period. For marginal-variegated plants, striped plants, crystal plants, 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 identical light requirements; for example, variegated plants, colored flowers and strong versus weak plants of the same species all differ in their light requirements. This is the "individuality" of orchid plants. The cultivator needs to observe carefully to correctly grasp the appropriate light for each kind of orchid.
3. Orchids can be roughly divided into three categories: sun-loving, semi-shade-loving and shade-loving. There are also long-day and short-day types. Long-day orchids bloom as the day gradually lengthens and the night gradually shortens; such as Cymbidium ensifolium and summer Cymbidium kanran that bloom in late spring and summer; short-day orchids are the opposite, blooming as the day gradually shortens and the night gradually lengthens, such as Cymbidium goeringii, Cymbidium goeringii var. longibracteatum, Cymbidium faberi and Cymbidium sinense that bloom in late autumn and winter.
4. Reference values for the optimal sunlight intensity of various orchids (unit: LUX)
Orchid species Sunlight range Optimal light intensity Variegated plant light intensity
Four Seasons Orchid 10000-14000 **** 10000
Cymbidium faberi 9000-13000 11000 9000
Cymbidium goeringii 8000-**** 10000 8000
Cymbidium goeringii var. longibracteatum 8000-**** 10000 8000
Cymbidium tortisepalum 8000-**** 10000 8000
Cymbidium kanran 8000-**** 10000 8000
Cymbidium sinense 4000-****5000 4000
"Fairburn and Prill point 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, day length, nutritional conditions, humidity, and the day-night temperature difference, etc." ---- Excerpted from Wu Yingxiang, "Chinese Orchids." Therefore, the sunlight intensity above is only a reference value.
5. The light intensity for orchids changes with the seasons: In winter and spring, orchids should receive more sunlight and basically need no shading. In summer and autumn, sunlight before 8-9 in the morning should be enjoyed more, while the west-facing sun 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 nurturing of winter buds, leading to fewer and poorer-quality seedlings in spring and affecting the whole year's growth rate.
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, it is suitable to fully receive light. Generally speaking: at 20-25°C, under direct sunlight, the chlorophyll of orchid leaves reacts quickly with light, and the plants grow vigorously. Above 30°C, the chlorophyll in the 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; if it lasts long, it starts from the leaf tips, and the whole plant gradually withers and dies, especially older plants which first turn yellow and then scorch. 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 orchids receive light over a large area. Also, because the morning sunlight is blocked by morning mist, the light is relatively soft, and direct exposure will not scorch orchid leaves. After orchids accumulate nutrients at night, their photosynthetic capacity is strongest in the morning.
V. Artificial regulation of light.
Light that is too strong or too weak is unfavorable to orchid growth, and orchid light varies greatly with season, weather, region, environment, etc. If light is too strong for these reasons, artificial shading must be used to adjust the shade density and reduce the light for orchids. If light is insufficient for these reasons and affects the healthy growth of orchids, artificial lighting must also be used to appropriately supplement light for orchids, giving them relatively ample light of sufficient duration. In short, to give orchids appropriate light, it must be regulated artificially.
1. The basis for regulating orchid light:
① Regulate the appropriate light for various orchids according to differences in their light requirements. Different orchid varieties also differ in their photosynthesis and optimal temperature. For example, different orchid species and variegation types differ at different times and in different regions. In the scorching sun of midsummer and golden autumn, regarding shading requirements, the shade density 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 variegated orchids can have about 80%, while high-grade variegated orchids, crystal-variegated orchids and pattern-variegated orchids should have about 90%. Flower-type orchids and ordinary variegated orchids can receive full light before 9 a.m. and after 4 p.m. on sunny days; high-grade variegated orchids, crystal-variegated orchids and pattern-variegated orchids should be half-shaded. In high-temperature "furnace" regions, the shading density should correspondingly increase by more than 5%. In winter and spring, appropriately increasing the light amount by 20% is more beneficial to orchid growth.
② Adjust the shade density according to the light duration and light intensity of different seasons. 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 bend downward or outward. Especially during the leaf emergence period, it makes the leaves grow rapidly. Conversely, too much light will make the leaves turn yellow or the chlorophyll be destroyed, causing cell death, and too much light makes the leaves shorter and thicker and open prematurely or bend outward. Therefore, except in early winter and midsummer, move orchids outdoors in the morning until 9-10 o'clock, so they get sufficient light. As the angle at which sunlight strikes the earth shifts, the light duration and light intensity all change. In the winter and spring seasons when light is short and weak, except that high-grade variegated orchids, crystal-variegated orchids and pattern-variegated orchids need 60%-70% shading, all other orchids can receive full light, or be half-shaded daily from 10-14 o'clock on sunny days. In the summer and autumn seasons when light is long and strong, the shading time and density for orchids must also be adjusted accordingly.
③ According to changes in weather. With ever-changing weather such as sunny, partly cloudy, cloudy, overcast, rainy and snowy days, light also changes frequently and correspondingly. Therefore, the shading degree must be appropriately adjusted as the weather changes and light strength varies. In particular, high-grade variegated orchids, crystal-variegated orchids and pattern-variegated orchids are not tolerant of strong light; if the shading degree is not adjusted in time, it often leads to sunburn damage. In addition, if a fixed shading density is 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, the morning and evening sunlight can be allowed to shine, the midday blazing sun must be blocked and regulated, and on cloudy days the shade density should be reduced. It is worth noting that after a summer rainstorm, or when it first clears after a long rain, orchid pots must absolutely not be exposed to the sun. The experience of predecessors: "If exposed to the sun right after rain, the water in the pot is hot, which scalds the leaves and injures the roots."
⑤ Regulate specifically according to differences in climate and light intensity in different regions. China has a vast territory, with differing climates and light intensities and relatively large differences, but the standards and requirements for strong, weak and appropriate 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 optimal temperature being 18-28°C. At temperatures as low as 0°C and as high as 40°C, the limit is reached, and orchid photosynthesis is inhibited. Starting from the low limit, photosynthesis strengthens as temperature rises. Beyond the optimal point, photosynthesis declines; above 36°C photosynthesis is very weak, and when the 40°C limit is reached, photosynthesis also stops. When temperature is high, use shading to cool down; when temperature is low, use heating equipment to raise the temperature, thereby achieving a relatively suitable temperature, promoting orchid photosynthesis, and ensuring the healthy and rapid growth of orchids.
⑦ According to the phototropism of orchids. Orchids have phototropism, so the direction of the orchid pot should be rotated and adjusted at intervals. This avoids the plant's leaves leaning to one side. Especially for the side with new growths, during the sprouting period it should face the direction with ample light, to facilitate sprouting and healthy growth of the shoots. If for the special needs of shaping or composition, 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 the orchid. Generally speaking, if the leaf color is pale green, and the orchid leaves are weak and spindly, then the light is too strong; if they are yellow-white and even scorched yellow or withered, it indicates that the light has exceeded the orchid plant's tolerance. Conversely, if the color is dark green or deep green without luster, it indicates that the light is too weak. Regulate shading well according to the growth condition of the orchid. In addition, if the stems and leaves are relatively dense and soft, with many leaf buds and few flower buds, then the light is insufficient; conversely, if the stems and leaves are sparse and firm, with few leaf buds and many flower buds, then the light is too strong. Both are abnormal and need timely adjustment.
⑨ Regulate light according to the growth period of the orchid; during the growing period, the supplemental light duration should be longer, and during the dormant period, a little less.
⑩ Based on professional testing. (Excerpt)
⑴ The light intensity for well-growing orchids is 4000-5000 Lux (lux, a unit of light intensity), and their sprouting rate, flowering rate, leaves and leaf color are all excellent.
⑵ 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 harmful rather than beneficial to orchids.
⑶ Plants most easily absorb red and blue light, and a balanced combination of red and blue light is especially important for photosynthesis. Experiments have proven that red light can promote the growth of orchids, while blue light is indispensable for thickening leaves, accelerating plant development, and regulating stomatal opening. Green light also cannot be ignored; it can promote the growth of oxygen, thereby helping orchids better accumulate nutrients.
⑷ A certain intensity of long-wave ultraviolet light is also indispensable; it helps form anthocyanins and inhibit the elongation of branches and leaves.
2. Methods for regulating orchid light:
First, shading. In nature, orchids mostly grow in cool, shaded mountain forest environments with scattered sunlight, and semi-shade and shade-loving types account for more than four-fifths of all orchid plants. Therefore, when light is too strong, shading must be used to reduce light.
(i) Plant shading. Imitating the natural environment, using plants for shade is one of the more ideal methods. The method is: on the orchid cultivation site, set up bamboo frames, wooden frames or reinforced concrete frames, and let vines such as grapes, honeysuckle, morning glory, Chinese trumpet creeper, and cypress vine climb and spread over them, which both provides shade and is attractive. Deciduous vines provide shade in summer and let light through in winter, which is a natural regulation. Trees can also be planted around the orchid garden, selecting evergreen trees, deciduous trees and bamboos of different heights to plant in combination, used to regulate light intensity.
(ii) Shade net shading. The shade shed can be built with bamboo, wood, angle steel, etc. as a frame, covered with bamboo blinds, plastic film, shade net, etc. On it, a double layer of shade net with a 50%-70% shading rate is set; the upper layer is relatively fixed and only rolled up in winter, while the lower layer can be put down or rolled up. In midsummer use double layers, in spring and autumn use a single layer; on sunny days at noon in summer and autumn use double layers, on cloudy and rainy days use a single layer. In winter, it depends on the situation; on sunny days let down the lower layer, on cloudy days roll up the lower layer. In addition, before orchid flower buds are about to bloom, there must be moderate scattered sunlight, otherwise the flower color is dim and does not appear pretty. It is best to install the shade net as a movable type, so that the shade density can be increased or decreased as needed. The shade net should as much as possible not be pressed tightly against the plastic film or glass on the top of the shed, and there should be a gap of about 30 cm between net layers. The shade net should be set outside the plastic film or glass, so that the shading effect is good. If it is set inside the shed, its shading effect is greatly reduced. When growing orchids on a balcony, at noon when sunlight is direct the light is strong, and the walls have reflected light and radiant heat, and ventilation is also poorer than in a courtyard or orchid site, so in the high-temperature season, a 50% shade net should be hung outside the security grille for 3-4 hours around noon to prevent scorching the orchids; when the sunlight is slanting and the temperature has also dropped, it should be rolled up in time to facilitate ventilation. Orchid shading requires a certain regularity. Generally speaking: large-leaved species require more than small-leaved species, and low-altitude species require more than high-altitude species. In summer more shading is needed, in winter less shading is acceptable; at noon more shading is needed, in the morning and evening less shading is acceptable; when hot more shading is needed, when cool less shading is acceptable, etc.
Second, "supplemental lighting." Regulating light in orchid-growing sites is not just about shading; when natural light is insufficient, artificial light must also be added to appropriately supplement light for orchids. This is especially true for indoor orchid growing and after the start of winter when the light duration is short, which has a certain impact on orchid growth. Only by supplementing light to meet the orchid's light requirements can the orchid plant develop soundly, have firm stems, grow and bloom.
(i) Basis for supplemental lighting. How to carry out appropriate supplemental lighting, and what kind of light to supplement? There must be a scientific basis. Sunlight is a collection of continuous bands of light from red to violet, and artificially simulating the plant growth environment should also start from this. In addition to considering the light quality and light intensity necessary for orchid growth, artificial supplemental lighting also needs to consider the physiological radiation characteristics of the light source. (Light waves that match the characteristic curve of plant chlorophyll synthesis are called physiological radiation light sources, i.e., photosynthetic light waves.) Under different light qualities, not only does the intensity of photosynthesis differ, but the photosynthetic products are also not entirely the same. For example: plants absorb red light most strongly, followed by blue light. When plants grow under blue-violet light, the amount of protein and fat in their photosynthetic products increases, and it 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, as it will scorch orchid leaves). Green light also cannot be ignored; it can promote the growth of oxygen, thereby helping orchids better accumulate nutrients. In addition, a certain intensity of long-wave ultraviolet light is also indispensable; it helps form anthocyanins and inhibit the elongation of branches and leaves. Supplemental lighting must select a suitable light source based on the effects of the above spectrum and the growth condition of the orchids.
(ii) Light source selection. Because light quality has a clear influence on the composition of photosynthetic products, people should select suitable light sources according to the type of photosynthetic products needed. 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. 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 is also cheap. Of course, if conditions permit, it is best to choose a plant lamp designed specifically for orchid supplemental lighting; it is 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 particularly strong durability and save electricity, reducing operating costs. When selecting a light source, one should consider not only light quality and light quantity, but also low power consumption, economy, durability and ease of use.
(iii) Supplemental lighting duration. After installing artificial lighting equipment in the orchid room, the supplemental 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. The supplemental lighting duration differs according to the different growth periods of orchids and the orchid-growing environment. Indoor orchid growing with weak light but able to receive scattered sunlight should have no less than 5 hours of supplemental lighting; balconies should have no less than 4 hours of artificial supplemental lighting; basements and indoor areas without sunlight should have no less than 10 hours of artificial supplemental lighting. During the orchid growing period, the supplemental lighting duration should be longer, and during the dormant period it should be a little less. On cloudy, rainy and foggy days, artificial supplemental lighting should be no less than about 10 hours. The supplemental lighting duration involves many factors and needs to be tested in practice to obtain a relatively correct supplemental lighting duration.
(iv) Light 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, so the height distance of the light tube can be adjusted to regulate light intensity, to adapt to the appropriate light requirements of different orchid species. How to choose the light distance: the installation distance of the supplemental light should be set according to the power of the lamp and the height of the orchid. The closer the lamp is to the orchid, the higher the light utilization, but care should be taken to avoid the lamp being too close to the orchid and the temperature being too high, which would cause harm to the orchid. Fluorescent lamps and plant-specific light sources (40W) should be at a distance of 20-40 cm; incandescent lamps (100W) should be installed at a certain height from the plant, because the large amount of infrared radiation from incandescent lamps converts to heat energy, so 70 cm or more is better; for high-pressure sodium lamps (120W-400W), the installation height should maintain a vertical distance of 1 m-1.5 m from the plant, which is more suitable. For LED supplemental light sources, because LEDs produce very little heat, they can illuminate at close range, and 10 cm is good.
(v) Light direction. To ensure the supplemental light intensity for orchids, the lamp should as much as possible be arranged directly above the orchid. Benefits: first, due to plant phototropism, with more overhead light, the orchid leaves have stronger uprightness, conforming 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 utilization efficiency.
(vi) Precautions for supplemental 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 within the plant.
② Pay attention to ventilation. Most supplemental 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 heat.
③ Comprehensive configuration of light sources. To obtain better supplemental lighting effects, 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 safety of supplemental lighting fixture installation to prevent accidents.
The above briefly describes the role of artificial supplemental lighting for orchids and some specific issues. In short, through appropriate supplemental lighting for orchids, ensuring orchids have relatively sufficient light can not only improve the cold resistance of orchids during overwintering, but also ensure the vigorous growth and abundant flowering of orchids in the coming year.
Third, "hardening." Orchids have relatively strong adaptability to light, which is also related to the number of generations of light intensity received. They will gradually change and adapt. For orchids that have always been shade-grown, 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 leaf structure and function of the plant 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, effectively using ample sunlight for photosynthesis. The folk so-called "hardening" roughly means this - letting orchids adapt to different environments - including light, temperature, etc. Through "hardening," they can be gradually strengthened generation by generation.
Fourth, display. In the display of potted orchids, according to the habits of various orchids, those with high light requirements should be displayed in places most exposed to 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 direction once or twice a month, to avoid the plant's leaves leaning to one side. Especially for the side with new growths, during the sprouting period it should face the direction with ample light, to facilitate sprouting and healthy growth of the shoots.
In summary, light plays a vital role in the growth, development, flowering and reproduction of orchid plants. Although orchids prefer shade, if all things in heaven and earth had no sunlight, they could not carry out photosynthesis to produce 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 constrained and influenced by external environmental conditions. These external factors are: light intensity, carbon dioxide and oxygen concentrations, wind speed, temperature, water supply, inorganic nutrients, and pollutants in the atmosphere and soil, etc. At the same time, light is also affected by the plant's own internal factors: for example, different orchid 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 raising the efficiency of plant photosynthesis be achieved. This promotes the healthy development, growth and flowering of orchids.
How to Grow Spider Plants Spider Plant Growing Tips
Spider plant, also known as: creeping stem grass, hanging orchid, fishing orchid, orchid grass, folding crane orchid; in Western Europe it is also called spider grass or airplane grass, native to South Africa. Its ornamental value is relatively high, the plant has the effect of purifying air, and the whole plant can be used as medicine. So how are spider plants grown? Today let's introduce it.
How spider plants are grown
Spider plants can be propagated by methods such as cuttings, division and sowing. Cutting and division propagation can be carried out at any time from spring to autumn. Spider plants have strong adaptability and a high survival rate, and are generally very easy to propagate. When taking cuttings, simply take a stolon 5-10 cm long with new buds and insert it into the soil; it will root in about a week, and after about 20 days it can be transplanted into a pot; water thoroughly and place in a cool place for maintenance.
Choose a suitable temperature for placement. Spider plants like a warm and humid climate and fear cold and high temperatures. They grow fastest at 24°C, stop growing above 30°C and below 0°C, and the leaves easily turn yellow and dry at the tips.
Spider plants should be placed in a place with suitable light. When cultivated outdoors in summer, pay attention to shading so that the light is not too strong, otherwise sunscald is very likely to occur.
Regulate water and fertilizer. In the peak growing seasons of spring and autumn, watering should be sufficient, the pot soil should often be kept moist, and the branches and leaves should often be sprayed with clean water close to room temperature to prevent dry tips, but there must be no water accumulation.
Pruning and repotting. As the plant grows, to maintain a good plant shape, the old leaves at the base should be pruned frequently, and the soil and pot should be changed at intervals.
Prevent pests in time. Spider plants have dense clumps and poor ventilation, and are susceptible to scale insect damage, so prevention should be the priority.
Spider Plant Growing Tips
1. Spider plants like a semi-shade environment, and in autumn strong direct sunlight should be avoided. Autumn sunlight is particularly strong, and during the day 50%-70% of sunlight needs to be blocked, otherwise the leaf tips will dry up, and variegated varieties are especially afraid of strong light. Golden-edged spider plants grow more beautifully in places with weak light, the yellow golden edges are more obvious, and the leaves are more glossy.
2. Spider plants are foliage plants that are relatively tolerant of fertilizer. If fertilizer and water are insufficient, they easily age, the leaves turn yellow, and they lose ornamental value. It is suitable to apply organic fertilizer liquid once every 7-10 days, but for variegated varieties such as golden-edged and golden-centered, less nitrogen fertilizer should be applied, to avoid the variegated leaf color becoming lighter or even disappearing and affecting appearance. Appropriately applying organic fertilizer fermented from bone meal, eggshells, etc., after full fermentation, take an appropriate amount of diluted liquid and water once every 10-15 days, which can make the variegated leaves bright and vivid.
3. Spider plants like a humid environment, and the pot soil should often be kept moist. In autumn, watering should be sufficient, and around noon and in the evening water should also be sprayed on the branches and leaves to prevent the leaves from drying up. If a lot of dust accumulates on the spider plant, it affects both its growth and its appearance, so the branches and leaves should often be sprayed with water to keep them bright and beautiful. Dead leaves and yellow leaves at the lower part should be removed at any time; normally maintain normal humidity, neither too dry nor too wet.
The above introduces the growing methods and growing tips for spider plants. The growing methods for spider plants are simple and easy to learn, with an extremely high survival rate. Interested friends might as well give it a try.