How to Cultivate Orchids in the North? Detailed Explanation of Bagging Care Techniques for Potted Orchids
Orchids are the national flower of our country and mainly grow in southern China. Orchid growth has certain environmental requirements. However, everyone knows that the climates of the north and south differ greatly, so can orchids be cultivated in the north? Below, the editor will provide a detailed answer for everyone.
Although the climates of the north and south differ greatly, orchids can also grow in the north. As long as you master the cultivation techniques, you can also grow beautiful potted orchids in the north. So, do you want to know the techniques for cultivating orchids in the north? If you want to know, follow the editor and read on.
(1) Increase air humidity. Bagging potted orchids can make the water vapor evaporated inside the pot less likely to escape. The growing medium in the orchid pot can also remain moist for a longer time, which can keep the roots and leaves of the orchid plant in a moist state. This promotes well-developed root systems, robust orchid seedlings, and emerald-green leaf sheaths, making them loved by all who see them.
(2) Newly planted orchid seedlings establish faster and bloom easily. Practice has proven that introduced artificially cultivated acclimated orchid seedlings, when purchased and planted, always go through a process of recovering and establishing. Using bagging to grow orchids, because the micro-environmental conditions are superior, greatly shortens the establishment period of the orchid seedlings. Northern orchid growers generally report that using this method to grow orchids not only helps the seedlings establish quickly but also makes them easy to bloom.
(3) It helps diseased and weak orchid seedlings recover vigor. Diseased and weak small orchid shoots have fragile vitality and need careful care during cultivation. Many northern orchid growers have experienced this. For example, in the 1990s some orchid enthusiasts in Tianjin raised diseased and weak small seedlings of variegated-leaf Cymbidium sinense and Cymbidium goeringii 'Da Fugui'. When cultivated by ordinary methods, still opening windows for ventilation or using electric fans, the result was that the orchids either dried up or the shoots rotted from the center, and eventually all died and were thrown away as garbage. In 1998, this orchid enthusiast selected flowering Cymbidium goeringii from the flower market. Because they were not cultivated well, all the seedlings collapsed, and some old pseudobulbs also rotted, leaving only 2 old small pseudobulbs. He decided to give it a try and put a plastic bag over this pot of diseased orchids. As a result, the "old heads" unexpectedly grew 2 small shoots one after another. Using the bagging method to grow diseased and weak orchid seedlings is suitable not only for the north but also for the south. According to records in "Shaoxing Orchid Culture," the famous orchid grower Ye Zhiqing used the bagging method to save a variegated Cymbidium kanran, and ultimately revived it. After recovering vigor, the variegated Cymbidium kanran even participated in an orchid exhibition.
(4) Bagging orchids results in fewer pests and diseases. Bagging orchids can be done throughout the year, and it does not matter even in high-temperature seasons. When using bagging to grow orchids in summer, putting your hand into the bag gives a scorching sensation, but orchid leaves are not damaged, and orchid roots also grow normally.
Northern potted orchids can adopt the bagging care method, because this can increase air humidity, promote flower opening, and also reduce pests and diseases. The above are techniques for bagging care of potted orchids in the north. Those who want to grow orchids can refer to them.
Cultivation, Planting, and Care of Phalaenopsis
I. Repotting
1. Pot selection: Generally use unglazed clay pots or plastic pots, with multi-holed pots being better. For better air permeability, shallow pots should be used, and the pot height should preferably be less than the pot diameter.
2. Selection of growing medium: Phalaenopsis is a typical epiphytic orchid with a well-developed root system. The growing medium must have the characteristics of being loose, ventilated, well aerated, and resistant to decay. According to the author's cultivation experience, for growing Phalaenopsis in the north, it is suitable to use pine needles, peanut shells, and bark strips locally as the medium. Repotting must be done every year. If repotting is not done in time, the potting medium will decay and cause compaction and poor aeration, and the orchid plant's growth will seriously decline or even die.
3. Repotting time and method: The best time to repot Phalaenopsis is late spring and early summer, preferably at a temperature above 20°C. At this time, the flowering period has just ended and new roots are beginning to grow. When repotting, first cut off the flower stem, gently remove the original nutrient pot, use your fingers to dig out the old medium from the lower part, cut off dried old roots, roots with rust spots, and broken roots, place broken tiles at the bottom of the pot, first put a layer of sterilized wet pine needles at the bottom of the pot, spread the Phalaenopsis roots evenly into the pot, then continue to place pine needles around the orchid root system, gently press down to make the orchid plant stand firm. When planting, note that the rhizome part of the orchid plant should be level with the pot rim, then spray water and place in a ventilated indoor area. During this period, do not fertilize. In terms of management, only spray water and water appropriately. After one month, leaf buds will grow, and then normal management can be carried out.
II. Temperature
Phalaenopsis is mainly distributed in tropical low-altitude coastal areas. The optimal growth and cultivation temperature is 25°C to 28°C during the day and 18°C to 20°C at night. Phalaenopsis is very sensitive to low temperatures. When kept at 15°C for a long time, it stops growing. When the temperature is below 15°C, the roots stop absorbing water, and necrotic black spots appear on the leaves. If this lasts too long, the leaves begin to turn yellow and fall off. Every year before winter and in early spring of the following year (that is, around the heating period) is a time of changeable northern climate, and indoor temperatures all fail to reach 15°C. This is the most difficult care period of the year. The orchid plant should be placed in a sunny spot indoors, watered less, and if necessary, water should be sprinkled on the ground, and at night the orchid plant should be bagged for insulation.
III. Watering
Phalaenopsis likes moisture but is averse to waterlogging. During the growing period, it must not lack water. If it lacks water for a long time, the leaves will turn yellow, and there will be no way to remedy it. Phalaenopsis grown in pine needles will not become waterlogged. When watering, use a spray pot to spray water until water flows out from the bottom of the pot. Frequently sprinkle water around the orchid pot to keep the air moist, but be careful not to let water accumulate in the center of the orchid leaves. In particular, do not spray water onto the leaves at night in winter.
IV. Fertilization
Because Phalaenopsis grows quickly and has a long growth period, light fertilizer should be applied frequently. In May, the orchid plant has just been repotted and is in the recovery period, so do not fertilize. From June to September, the orchid plant is in its growing period, so fertilizer should be applied once a week, alternating foliar fertilizer and potassium dihydrogen phosphate. You can also use farmyard manure fermented with water to irrigate as liquid fertilizer. If conditions permit, you can buy special orchid fertilizer and "Hua Bao" liquid fertilizer, dilute 2000 times, and spray on the leaf surfaces and growing medium. Stop fertilizing during high summer temperatures. In late autumn, the orchid plant's growth gradually slows, so fertilization should be reduced. Too much fertilizer often causes the orchid plant to grow too vigorously, affecting flower bud formation and resulting in failure to bloom.
V. Ventilation and Shading
Phalaenopsis likes ventilation and is averse to stuffiness. Poor ventilation easily causes root rot and poor growth. In winter, when temperatures are low, short periods of ventilation can be given at noon on sunny days, but the air inlet should not blow directly onto the orchid plant. In its natural state, Phalaenopsis grows epiphytically in the shade of dense forest trees, forming a habit of liking semi-shade. When cultivated at home, provide less shading in winter and more shading in spring and autumn. In summer, when sunlight is strong and temperatures are high, special attention should be paid to shading and strengthening ventilation.
VI. Flowering Period Management
Because of limitations of temperature and humidity when growing Phalaenopsis at home, only 2 to 3 leaves can grow in a year. The leaves grow singly at the top, and the flower buds grow between two leaves. After the flower buds form, at a temperature of 18°C to 20°C, they can bloom after 3 to 4 months of care. After the flower stem emerges, first set up temporary support in the pot to prevent the flower stem from lodging. The flower stem should be fixed in multiple steps to avoid breaking it. When the first flower bud grows larger, the orientation of the pot must not be rotated, otherwise the flowers on the Phalaenopsis will face inconsistent directions. During the full blooming period, the temperature should be controlled between 15°C and 18°C, and ventilation and humidity should be strengthened. The flowering period can last as long as 4 months.
VII. Pest and Disease Control
1. Leaf spot disease: It mainly occurs on the leaves. In the early stage of the disease, small spots appear on the leaves, which later develop into nearly round lesions. The edges of the lesions have a water-soaked yellow halo with clear boundaries. Control methods: strengthen ventilation, reduce air humidity, and cut off diseased leaves. During the disease period, spray with 75% chlorothalonil wettable powder at 800 times dilution, once every 10 days, for 3 consecutive sprays.
2. Gray mold: It occurs in spring during low temperature and high humidity. Generally, small brown spots appear on the petals of white flowers, and in severe cases soft rot occurs. Control methods: strengthen ventilation, reduce humidity, and immediately cut off affected flowers. In the early stage of the disease, spray with 75% thiophanate-methyl wettable powder at 1000 times dilution, once every 10 days, for 2 consecutive sprays.
3. Brown spot disease: It occurs in summer and autumn during hot and humid weather, mainly on the leaves. In the early stage of the disease, small round spots appear on the leaves, which gradually expand into large spots. The lesions are dark brown, and in severe cases the leaves turn black and wither. Control methods: pay attention to ventilation and light transmission. In the early stage of the disease, spray with 10% Polyoxin at 80 times dilution once every half month.
4. Scale insects: The most common insect pest of Phalaenopsis, mostly occurring in autumn and winter. Poor indoor ventilation and dryness lead to scale insect damage. Control methods: pay attention to ventilation, do not place orchid plants too densely, and when only a small number are found, use a soft cloth to wipe off the scale insects. Repeated several times can eradicate the pest.
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Key Points for Winter Care of Courtyard Flowers
Key Points for Winter Care of Courtyard Flowers
(1) Winter climate characteristics. China is the country with the most prominent monsoon climate characteristics in the world. Most regions are affected by monsoons, so seasonal changes are very obvious. East China is located in the warm temperate and subtropical climate zones, with a large north-south latitudinal span (over 12 degrees), and temperature changes throughout the year are obvious, with the four seasons of spring, summer, autumn, and winter being relatively distinct. Here, summer is affected by maritime climate, with southeasterly winds predominant and abundant rain, while winter is affected by cold air currents from Siberia, with northerly winds predominant, dry conditions, and continuous cold waves. The average temperature of the coldest month of the year is below 0°C, while areas south of the Huai River are above 0°C. Annual rainfall is around 1000 mm and is concentrated in summer. Winter rainfall is relatively low, with more rain in the south and less in the north.
The winter referred to here is the winter of the East China region, beginning in late November each year and lasting until early February of the following year. This season is the coldest period of the year. And from late December each year to January of the following year is the coldest period within winter, when the minimum temperature reaches about -14 to -12°C. The agricultural proverb "In the first and second nine-day periods, do not stretch out your hands; in the third and fourth nine-day periods, walk on ice" refers to this period.
In areas such as Jiangsu, Anhui, and Shanghai, because the terrain is relatively low and flat, they are extremely vulnerable to cold wave invasions in winter. For flower growers, this increases the difficulty of getting home-grown flowers to safely overwinter, especially warmth-loving flowers and foliage plants. Flowers native to tropical and subtropical regions are even more susceptible to cold damage when grown in winter. The care and management of indoor flowers in winter is a issue of great concern to every family that loves and grows flowers.
(2) The impact of winter climate on flowers. Temperature is an important condition for flower cultivation and often plays a key role in the survival of various flowers. It can also be said that even if other conditions are suitable, without suitable temperature, flowers cannot even survive. Some flowers do not have temperature problems in their place of origin or in warm seasons, but when moved to another place or when the weather turns cold, the temperature must be adjusted in a timely manner and cold protection measures must be taken. Why do some flowers have particularly strong cold resistance while others are very poor? Because when winter comes, cold-resistant flowers accumulate a large amount of soluble sugar in their cells, the concentration of body cell fluid increases, osmotic pressure rises, and the freezing point drops, so they can resist low-temperature invasion in cold winter. Tropical flowers are just the opposite. When the environmental temperature drops, their body cells cannot immediately accumulate a large amount of soluble sugar, so they are extremely susceptible to frost injury or even death. Different flowers have different temperature requirements in winter. To understand these differences, it is necessary to understand the temperature conditions of the places of origin of different flowers. Flowers have their own patterns of growth and development. Generally, low-temperature-tolerant flowers cannot endure high-temperature environments, while high-temperature-tolerant flowers are likewise not suited to low-temperature environments. Through long-term cultivation, people have grasped some ecological characteristics of common flowers, usually summarized into 3 categories:
① High-temperature type: such as poinsettia, gloxinia, Brazil wood, Aglaia odorata, croton, African violet, etc. These flowers are native to the tropics, and some only bloom under high-temperature conditions. The minimum temperature in their places of origin is not lower than 10°C, so in the East China region the minimum indoor temperature in winter should not be lower than 12°C.
② Medium-temperature type: such as white orchid, jasmine, hibiscus, cyclamen, calla lily, Western azalea, etc. These flowers are all cultivated in open courtyards in the Guangzhou area. The minimum temperature in the Guangzhou area in a year is around 1°C, so in the East China region the minimum indoor temperature in winter should not be lower than 5°C.
③ Low-temperature type: such as osmanthus, kumquat, plum, pomegranate, etc. These flowers are all cultivated in courtyards in central China and southern East China. The minimum winter temperatures in these areas are all around 0°C, so in the East China region the minimum indoor temperature in winter should not be lower than 0°C.
(3) Winter management of home-grown flowers. In the East China region, when winter comes, for some potted flowers native to tropical and subtropical regions, it is very important to take necessary freeze-prevention and warmth-preserving measures. For example, many families like to grow Aglaia odorata, clivia, Chloranthus, hibiscus, rubber tree, Brazil wood, cyclamen, gloxinia, jasmine, etc., as well as succulent and juicy flowers. In late autumn, they must be moved indoors or into warm sheds one after another. How can southern flowers grown at home be ensured safe overwintering? The following measures can be taken:
First, understand the characteristics of the flowers and place them by category. The winter care of potted flowers should be treated differently according to the growth characteristics of the flowers and their temperature requirements. In winter, the outside temperature is relatively low. Most flowers cultivated indoors are in a dormant or slow-growing semi-dormant state. For flowers that go dormant in open ground, such as peony, chrysanthemum, pomegranate, Chinese rose, crabapple, plum, etc., they can be placed on balconies, in front of ground-floor windows, or in relatively low-temperature indoor areas, and generally can overwinter naturally. If a cold wave hits, they can be covered with plastic film for insulation, and the film can be removed after the cold wave passes. For flowers in a semi-dormant state in winter, such as ornamental citrus, azalea, clivia, camellia, cyclamen, rubber tree, Schefflera, etc., generally a room temperature maintained above 5°C is enough for safe overwintering. For flowers that continue to grow in winter, such as cineraria, primrose, cyclamen, asparagus fern, etc., generally a room temperature maintained at 8 to 10°C allows natural overwintering, and if a cold wave hits, insulation measures should be taken. For the few flowers from the tropics and those that need to be cultivated in winter for holiday viewing, such as tropical orchids, poinsettia, pothos, Brazil wood, Aglaia odorata, tuberous begonia, gloxinia, etc., they need to overwinter at a room temperature above 15°C. In the East China region, most families generally do not have heating facilities. To ensure the safe overwintering of tropical flowers grown at home, indoor heating or other measures are needed to raise the room temperature.
Second, conduct regular inspections and water moderately. Because various flowers in winter have inconsistent requirements for temperature, moisture, and light, regular inspections are needed. Timely and moderate water supplementation is one of the important guarantees for safe overwintering. Watering indoor flowers should also follow the principle of alternating dry and wet for potted flower watering. In terms of watering time, grasp the principle of watering on sunny days and not on cloudy days, and watering at noon rather than in the morning or evening. The specific amount of water should be flexibly controlled according to the type of flower, the amount of water required at its growth stage, the nature of the pot, etc. Generally, water once every 7 to 10 days. In addition, learn to water by observing the flowers. So-called observing the flowers means grasping the characteristics of the flowers and not applying the same rule to all. For example, moisture-loving flowers such as umbrella plant, spider plant, Monstera, and Schefflera should be watered more, while drought-tolerant flowers such as Christmas cactus, Brazil wood, sago palm, and cactus types should be watered less. Evergreen foliage flowers can be watered by spraying the leaf surfaces.
Third, insulate and protect against cold by category and increase light. Temperature management during the wintering period of potted flowers should be treated differently according to the growth state of the flowers and their different temperature requirements. If placed under the same temperature conditions, it is inevitable that some flowers will adapt and grow well, while others will not grow well because they do not adapt. If high-temperature flowers are placed in a low-temperature environment, cold damage or even death from freezing will occur. However, if some low-temperature-loving flowers are placed in a high-temperature environment, it will affect their growth the following year. This point is often overlooked by people. If low-temperature-loving flowers are kept in a high-temperature environment for a long time in winter, they will consume too many nutrients, which will affect their growth and flowering the next year. Therefore, when cultivating potted flowers indoors in winter, they must be treated differently according to their different temperature requirements. Families with the means can divide the flowers they grow into 3 categories: low-temperature, medium-temperature, and high-temperature flowers. Place low-temperature flowers in north-facing rooms, but they need to be regularly moved to sunny rooms to sun themselves; place medium-temperature flowers in south-facing rooms or enclosed balconies, and if a cold wave hits, appropriate insulation measures are still needed; high-temperature flowers not only need to be placed in south-facing rooms but also need added heat, keeping the indoor temperature above 12°C.
① Winter cold protection for indoor potted flowers: Most potted flowers are not locally native, mainly tropical and subtropical evergreen flowers. Because they are not suited to the natural conditions of their new location, they need to be moved indoors or into greenhouses for care in winter. As far as the East China region is concerned, from north to south, the time of entering the greenhouse differs slightly: the Huaibei area is about mid-to-late October, the Nanjing area is mid-November, and they are gradually moved outdoors in mid-to-late April of the following year.
During the wintering period of potted flowers, suitable environmental conditions for overwintering should be created according to the growth habits of the flowers and the different requirements of various flowers, which still involves factors such as temperature, humidity, light, and air.
The first issue is temperature, which should be treated differently according to the different temperature requirements of flowers and trees. In winter, the outside temperature is relatively low. Most flowers cultivated in cold rooms are in a dormant or slow-growing semi-dormant state. For flowers that go dormant in winter, such as Chinese rose, chrysanthemum, peony, hydrangea, etc., generally placing them in a cold room at 3 to 5°C is enough for safe overwintering. For flowers in a semi-dormant state in winter, such as ornamental citrus, azalea, gardenia, plum blossom, clivia, Crinum, camellia, etc., although their temperature requirements are slightly higher, generally placing them in a cold greenhouse below 5°C also allows safe overwintering. Such temperature conditions can basically be met without heating in areas south of the Huai River. However, for flowers that can continue to grow in winter, such as wax begonia, cineraria, Aglaia odorata, asparagus fern, Christmas cactus, etc., they should generally be placed in a greenhouse at room temperature of 8 to 10°C or above, which requires indoor heating or warming facilities. For the few flowers from the tropics and those that need to be cultivated in winter for holiday viewing, such as tropical orchids, poinsettia, cyclamen, tuberous begonia, Monstera, etc., a temperature of 15 to 17°C or above should be provided. In areas south of the Huai River, there is generally no heating indoors in winter, so flowers must be placed in rooms with dedicated warming facilities or in south-facing sunny cold rooms.
During the wintering period, the room temperature has a relatively large impact on potted flowers. For example, warmth-loving flowers such as jasmine, poinsettia, Aglaia odorata, and croton, when placed in a cold environment with room temperature close to 0°C, will be on the verge of death before long; when placed in a relatively cold environment below 10°C, they will enter a semi-dormant state with stagnant growth and yellow leaves and withered branches; when placed in a relatively warm environment around 15°C, they will only barely sprout and unfold leaves and grow slowly, but cannot form buds and bloom.
Once potted flowers are brought indoors, attention must also be paid to cold protection. The room where potted flowers are placed should have good heat preservation and cold insulation capacity, and flowers with the same warmth-loving habits should be placed in places with similar temperatures. For cold-resistant flowers in a dormant state, they can be placed in corners of rooms with lower temperatures to keep them dormant; for warmth-loving evergreen flowers or those still growing in winter, they should be placed as close as possible to south-facing windows, where sunlight is relatively abundant and the usual temperature is relatively high. Generally, non-cold-resistant evergreen woody flowers must not be placed near windows and doors that are frequently opened, so as to avoid cold wind invasion causing the plants to freeze, wither, and drop leaves, or even die. Entering the cold winter months, use paper strips or soft foam plastic strips to seal door and window gaps to prevent wind, and at night hang door curtains and window curtains in the room where potted flowers are placed, so that the indoor temperature is at least 3 to 4°C higher than outdoors. Usually pay close attention to changes in indoor and outdoor temperatures to avoid temperature loss of control and unnecessary damage to flowers. For flowers that truly have difficulty overwintering in cold rooms, the following methods can be used:
Make flower insulation covers: For Aglaia odorata, white orchid, jasmine, etc., first use wire to form an arched ring support along the pot rim, then cover the plant together with the pot using plastic film. If the weather is especially cold, double-layer film can be used to cover and protect the flowers. This method is simple and easy to carry out, with remarkable insulation effects, and can enhance the cold resistance of flowers. However, several small holes should be left in the plastic cover to facilitate ventilation and air exchange. In addition, the leaves of the flowers should not be close to the bag. If the room temperature is too low, the potted flowers still need to be moved to a warmer place to avoid frost damage.
Use nested pots for insulation: For some flowers, such as Aglaia odorata, clivia, Chloranthus, etc., an outer or lower pot can be added to maintain temperature. The specific method is: use a slightly larger flower pot, fill it with some insulation material or put soil in it, and embed the pot containing the flower into the larger pot; or stack the potted flower on top of a pot with soil so that the potted flower is off the ground. This method can also play an insulation role.
Self-made incubator method: The volume of the incubator can be determined according to the size and number of flowers placed. Its front and two sides should preferably be made into openable and closable movable doors. The box can be divided into upper and lower compartments, and the dividing layer and shelf boards should use wire mesh boards to facilitate upward heat dissipation. Two electric lamps should be installed at the bottom inside the box. The wattage of the bulbs depends on the internal volume of the box. Generally, it is appropriate to maintain the box temperature above 15°C. Because humidity will decrease after the temperature inside the box rises, a small cup of water should be placed between the two lamps to maintain humidity. In order for the flowers in the box to use natural light, the movable doors are best made with transparent glass, and if conditions permit, artificial lighting lamps can also be installed to increase the amount of light. This method is expensive and high in cost, and a simple small greenhouse made of plastic film can also be used instead.
In addition to the above insulation methods, indoor potted flowers should also be inspected frequently. If it is found that the plant's growth is deteriorating or symptoms of freezing appear, remedial measures should be taken as soon as possible. Some people move frozen potted flowers to the side of a stove to warm them, and others move them outdoors to bask in the sun. These practices are all wrong. The correct method is: first place them in a slightly warm room to let them slowly recover, then gradually raise the temperature, but do not water at will. If watering is needed, it must be done at noon when the temperature is relatively high, and cold water must not be used directly to water the flowers.
Potted flowers need cold protection in winter and also in spring, especially warmth-loving flowers such as Aglaia odorata, white orchid, jasmine, and poinsettia. Freezing damage often does not occur in winter when temperatures are lowest, but mostly appears in early spring when temperatures begin to rise. The reason is: when flowers go from a dormant state into a state of growth and sprouting, due to their own physiological functions, they quickly lose their resistance and tolerance to low-temperature freezing damage. In early spring, the weather is changeable. In addition to strong winds and dryness, temperature rises and falls are also unstable, hence the saying "Spring is like a child's face, changing three times a day." Especially when a cold wave passes, within 24 hours, the temperature can suddenly drop by 5 to 8°C or more. After a long winter of indoor cultivation, most flowers are already very weak and have poor adaptability, but at this time people think spring has arrived and relax their vigilance against bad weather, moving flowers out of the room too early. If they then encounter late frost, a cold wave, or cold air invasion, even if the temperature is not too low, the flowers will suffer freezing damage because they cannot adapt to changes in the external environment. Therefore, experienced flower growers all understand the principle that potted flowers should "not leave the room in spring."
Before potted flowers leave the room, indoor ventilation should be strengthened. You can first open doors and windows during the day when the temperature is relatively high, and close them at night. Later, as the temperature rises, gradually extend the time the doors and windows are open, lower the indoor temperature, narrow the temperature difference between indoors and outdoors, and gradually improve the adaptability of potted flowers to the outdoor environment. After a period of adaptive training, overwintered potted flowers can gradually reduce their care time indoors and safely leave the room at the appropriate time. The specific time for potted flowers to leave the room should be sequenced according to the cold resistance of each type of flower. For example, osmanthus, Chinese rose, plum, etc., can leave the room when the daily average temperature reaches about 10°C, while flowers such as Aglaia odorata, hibiscus, and jasmine should leave later. After the last cold wave passes and the daily average temperature stabilizes at around 15°C, moving them outdoors is much safer.
② Winter cold protection for balcony flowers: Modern urban population density is increasing. Multi-story and high-rise buildings with complete functions create a comfortable living environment for people. Adapting to local conditions and using balconies to grow flowers can give people aesthetic enjoyment. Moreover, balcony flowers along streets directly form a landscape line of the city, and they are beneficial for reducing noise, preventing pollution, adding interest to life, and purifying and beautifying the city.
Here we mainly discuss some flower-growing knowledge for winter balcony flowers. Modern residential balconies have 2 types: one is enclosed at the time of construction, such as most high-rise buildings and a few multi-story buildings; the other is not enclosed, such as most multi-story buildings, which still have open balconies.
Cold protection for flowers on enclosed balconies: In winter, enclosed balconies can play the role of a greenhouse and have a certain heat-preserving and warming effect. Some warmth-loving medium-temperature flowers cannot safely overwinter outdoors, but on enclosed balconies they are basically not subject to freezing damage. Therefore, plants such as asparagus fern, fuchsia, wax begonia, clivia, Christmas cactus, epiphyllum, azalea, cyclamen, spider plant, banana shrub, sago palm, and some foliage plants can all safely overwinter when placed on enclosed balconies.
Cold protection for flowers on open balconies: Open balconies have fast air circulation, large evaporation, and low relative air humidity. In winter, because northerly winds predominate and wind force is also relatively strong, whether it is a north balcony or a south balcony, even flower varieties that can usually overwinter in open ground locally still need appropriate cold protection on open balconies, especially in areas north of the Yangtze River. South balconies of multi-story buildings are mostly open. Because they are sheltered from the wind and face the sun, freezing damage or cold damage to flowers is far less prominent and severe than on north balconies, so in winter flowers are generally placed on south balconies to overwinter. Some relatively cold-resistant flowers can usually safely pass through winter on south balconies with only slight management, such as woody types like Chinese rose, nandina, banana shrub, gardenia, longevity peach, winter jasmine, wintersweet, crabapple, osmanthus, pomegranate, plum blossom, peony, kumquat, etc., and herbaceous and perennial types such as chrysanthemum, tuberose, tulip, orchid, canna, amaryllis, etc. However, open balconies have strong winds and low air humidity, and the potting soil dries out extremely easily, so the flower varieties selected must be suited to this environment. They must be drought-tolerant and low-temperature-tolerant, and close attention must be paid to changes in the dryness and wetness of the potting soil. Watering too frequently is not good, and not watering at all is also not good. Some varieties in a dormant state can be watered less, while some evergreen varieties can appropriately have their watering frequency increased, and water can also be frequently sprayed on the leaf surfaces. Bulbous, tuberous, and perennial flowers are relatively drought-tolerant and can be watered less, such as amaryllis, tulip, canna, iris, bletilla, tuberose, peony, lucky grass, evergreen, dianthus, chrysanthemum, etc. When a cold wave hits, preventive measures are still needed. A simple temporary insulation frame can be built on the balcony, covered with plastic film on the outside. In areas north of the Yangtze River, double-layer plastic film can be used. Plastic film covers can also be used to cover the entire potted flower to achieve insulation and cold protection. In addition, some warmth-loving flowers can be temporarily moved indoors to prevent freezing damage.
③ Winter cold protection for courtyard flowers: Some families with courtyards like to grow flowers and grass in the courtyard, but some varieties introduced from the south have poor cold resistance, and there is also the problem of winter cold protection.
Generally speaking, open-ground-cultivated annual and biennial herbaceous flowers, perennial flowers, and some flower and tree types have relatively strong adaptability, such as chrysanthemum, petunia, stock, red woodsorrel, daylily, peony, Chaenomeles speciosa, Chinese rose, etc. However, there are also some flowers such as large-flowered chrysanthemum, canna, banana shrub, Canna edulis, osmanthus, etc. Although they have a certain cold-resisting ability, they are not tolerant of low temperatures. In areas north of the Yangtze River, protection still needs to be strengthened in winter to ensure safe overwintering of flowers. The following methods are often used for cold protection of open-ground flowers:
The first method, careful management to enhance the cold resistance of the flowers themselves: When autumn arrives and the weather gradually turns cool, flowers enter the late growth stage. At this time, control the application of nitrogen fertilizer, apply more phosphorus and potassium fertilizer, and at the same time moderate the amount of watering, so that the plants grow solidly and enhance their resistance to cold. After entering the winter dormant period, one intertillage and fertilization can be carried out, and barnyard manure, night soil, or cake fertilizer can be applied to increase the concentration of the soil solution and enhance the cold resistance of open-ground flowers.
Some perennial flowers and overwintering annual herbaceous flowers, such as peony, canna, dahlia, tulip, edgeworthia, etc., are prone to freezing damage when overwintering naturally in areas north of the Huai River. If a cold wave comes, materials such as fallen leaves, rice straw, straw mats, or plastic film can be spread on the ground at the root zone of the flowers. This method is simple, effective, and very commonly used, and it can be removed after the late frost passes.
The second method, earthing up and mounding soil for winter freeze protection: Some flowers, when winter comes, have all aboveground parts go dormant, with only the fibrous roots still growing slowly, such as peony, hydrangea, hibiscus mutabilis, etc. Soil can be mounded around the root area of the flowers to form a small mound. When the plants begin to sprout in spring, the mounded soil can be opened up.
The third method, wrapping with insulation materials for winter cold protection: For some larger ornamental flowering trees, because the tree body is relatively large and cannot be pressed down and buried or covered, methods such as wrapping with grass, wrapping with paper, and covering with plastic film can be used for cold protection. For some flowering trees with relatively strong cold resistance but fear of cold wind, or newly planted flowering trees, the method of setting up windbreaks can be used, that is, using reed mats and other materials to set up windbreaks on the west and north sides of the flowering trees. This method is commonly used for cold protection when planting deodar cedar in areas north of the Huai River.
(4) Winter water management for flowers. For home flower growing, how to water flowers, whether to fertilize, and whether propagation can succeed are all issues of concern to home flower growers. Below is a brief introduction to the water management of potted flowers in winter.
① Watering flowers in winter: For home flower growers, watering is the most frequent and most important care task. Winter watering is likewise a key task related to whether flowers can safely overwinter. People often attribute flower death caused by improper watering to improper insulation, but in fact many household flowers die in winter because of too much water.
Home flower growers should know that winter is the dormant period for flowers. If the potting soil remains in a high-moisture state for a long time, it will inevitably cause root rot. Therefore, attention must be paid to watering time, watering amount, and watering method.
Watering time and water amount for flowers in winter: Ground-planted flowers, because their root systems are relatively well developed, generally do not need watering in winter. They can be watered sufficiently after leaf fall and before the ground freezes, and then they can be left alone for the entire winter.
During the transition from autumn to winter, potted flowers grow slowly because sunlight weakens and temperatures gradually drop. At this time, leaf transpiration and soil surface evaporation decrease accordingly. In the north, most potted flowers have been moved indoors to overwinter. Overall, the potting soil should be kept on the dry side, maintaining about 30% humidity, that is, the potting soil being moist is sufficient. Special attention should be paid to the amount of watering from December to January of the following year, because this period is the colder time of winter in North China. If water is not strictly controlled, it will not only weaken the cold resistance of the flowers, but the flowers will also be extremely prone to death. If the potting soil truly needs watering, generally watering once every 1 to 2 weeks can meet the need. For the few with high water demand, such as foliage plants, watering once every 4 to 5 days is acceptable. Absolutely do not water too frequently. Usually, spray more water on the leaf surfaces to reduce the number of times watering the potting soil. Some home flower growers, as soon as they see the surface of the potting soil looking a bit dry, think the flowers are short of water. In fact, in winter, this situation is not serious, because although the surface of the potting soil is a bit dry, the lower soil is still moist. Winter flowers have very little water demand. As long as the potting soil has a certain humidity, the flowers will not die. For larger plants, because their own water demand is high and their stress resistance is relatively strong, there is not much problem if they are watered too much. For small plants, especially succulent and juicy flowers, water must be strictly controlled, and watering must wait until the potting soil is completely dry. In short, watering flowers in winter should be dry rather than wet, mainly by spraying leaf surfaces, minimizing watering of the potting soil, so as to keep the potting soil in a dry state for a long time.
② Water temperature and methods for watering flowers in winter: The water temperature for watering flowers in winter is particular. Generally speaking, it is enough for it to be a few degrees Celsius higher than the soil temperature. The usual practice is to store water for watering flowers in advance in an open container, and use it when the water temperature, air temperature, and soil temperature do not differ much. Warm water can also be added. For evergreen potted flowers, warm water above 10°C and below 15°C can be sprayed on the leaf surfaces, which not only achieves the purpose of watering but also prevents damage to flowers from dry freezing. If cold water is used to water flowers in a low-temperature environment, the low air temperature and low water temperature will aggravate the damage to potted flowers. Winter flowers do not need much water, but that does not mean they do not need water. In principle, water when dry, and water thoroughly at one time.
When watering in winter, different watering methods can be used according to different flowers:
Immersion method: Immerse the potted flower together with the pot into water, letting water slowly seep in along the bottom hole of the pot, until the surface soil looks moist, then take the potted flower out. This method can make the soil absorb water fully and is relatively ideal. Moisture-loving flowers such as umbrella plant and calla lily have relatively high water demand and can use this method. Other flowers should use the immersion method as little as possible in winter.
Sprinkling method: According to the actual needs of the flowers, supply water in a planned way, but when sprinkling, stop when water is seen seeping out from the bottom of the pot.
Fine-hole mist spraying method: Use a fine-hole spray pot to turn water droplets into mist and spray it on the leaf surfaces of flowers, such as asparagus fern, spider plant, Western azalea, Schefflera, rubber tree, cineraria, clivia, etc. The mist spraying method can both give higher humidity on the leaf surfaces and around the pot, and also keep the leaf surfaces clean.
Selection of water quality for watering flowers in winter: For flower irrigation water, natural water such as river water and pond water is generally better. Tap water, because it contains bleaching powder, liquid chlorine, alum, etc., will alkalize and harden the potting soil after long-term use. It is best to first store it in a vat or other container for 2 days before use. Turbid water is not suitable for watering flowers, and water containing salt or alkali is also not suitable for watering flowers.
(5) Winter pests and diseases of flowers. Winter pests and diseases are generally relatively few, but some pests and diseases may also appear in rooms with heating or higher temperatures, which both affects the healthy growth of flowers and affects ornamental value, so attention must be paid to the prevention and control of pests and diseases. Generally, households mainly rely on prevention, maintaining suitable temperature and humidity, good indoor ventilation, and suitable soil dryness and wetness. When sowing, the soil must be sterilized. Selecting robust seeds or introducing flower seedlings without pests and diseases are all effective measures to prevent pests and diseases.
Common diseases include powdery mildew, anthracnose, root rot, rust disease, root nodule disease, leaf spot disease, brown spot disease, and chlorosis, etc. Diseases may occur throughout the entire growth period of flowers, but they are most common in the high-temperature and rainy season from June to August. A small number of pests and diseases can also occur in winter.