A Detailed Guide to Overwintering and Keeping Warm Garden Flowers in Home Courtyards
At present, most families with courtyards like to plant grass and grow flowers in their courtyards. Some flower varieties introduced from the south have poor cold tolerance and mostly need cold protection during the winter. Generally speaking, open-ground cultivated herbaceous flowers, perennial flowers and some nursery stock are highly adaptable, such as chrysanthemums, stock, peonies, Chinese roses, etc. But there are also some flowers such as dahlia, banana shrub, osmanthus, etc. that, although having a certain ability to resist the cold, are not tolerant of low temperatures, especially in areas north of the Yangtze River, where protection should be strengthened in winter to ensure the flowers survive the winter safely.
Careful management: When the weather turns cool in late autumn, flowers enter the late stage of growth. At this time, nitrogen fertilizer application should be controlled, and more phosphorus and potassium fertilizers and magnesium, boron, zinc and iron micro-element fertilizers, root-promoting agents, etc. should be applied. At the same time, the amount of watering should be controlled to promote solid plant growth and enhance their cold resistance. After entering the winter dormancy period, cultivate and fertilize once, mainly with barnyard manure, dung, cake fertilizer, etc., to increase the concentration of the soil solution and further enhance the cold resistance of open-ground flowers.
Covering for overwintering: Some perennial flowers and biennial herbaceous flowers that overwinter in open ground in courtyards, such as Chinese peony, canna, dahlia, tulip, etc., are prone to freezing injury or cold injury when overwintering naturally in areas north of the Huaihe River. Generally, before the cold wave arrives, materials such as leaves, wheat straw, rice straw or plastic film are spread on the ground around the root zone of the flowers to keep warm, retain moisture and prevent freezing. After the late frost at the end of April the following year, these coverings should be removed.
Ridging soil around the roots: Some flowers have all their above-ground parts go dormant when winter arrives, but their fibrous roots are still growing slowly, such as tree peony, hydrangea, cotton rose, osmanthus, Chinese rose, etc. Soil should be ridged around the roots of these flowers; when the plants begin to sprout in spring, the ridged soil should be dug open, and watering and fertilizing management should be carried out.
Wrapping with insulation materials: For some larger ornamental flowering trees, because the tree body is relatively large and cannot be pressed into the soil or covered, methods such as wrapping with fine straw rope, wrapping with straw, wrapping with paper, and covering with plastic film can be used for cold protection; for some flowering trees with relatively strong cold resistance but afraid of cold wind, or newly planted flowering trees, the method of setting up wind barriers can be used, that is, using reed mats, tree sticks, corn stalks and other materials to build wind barriers on the west and north sides of the flowering trees. For example, cedar and dragon juniper planted and propagated in areas north of the Huaihe River can use this method for cold protection.
How to Overwinter and Keep Warm Garden Flowers in Home Courtyards
Water and Fertilizer Management
When the weather turns cool in late autumn, flowers enter the late stage of growth. At this time, nitrogen fertilizer application should be controlled, and more phosphorus and potassium fertilizers and magnesium, boron, zinc and iron micro-element fertilizers, root-promoting agents, etc. should be applied. At the same time, the amount of watering should be controlled to promote solid plant growth and enhance their cold resistance. After entering the winter dormancy period, cultivate and fertilize once, mainly with barnyard manure, dung, cake fertilizer, etc., to increase the concentration of the soil solution and further enhance the cold resistance of open-ground flowers.
Covering for Overwintering
Some perennial flowers and biennial herbaceous flowers that overwinter in open ground in courtyards, such as Chinese peony, canna, dahlia, tulip, etc., are prone to freezing injury or cold injury when overwintering naturally in areas north of the Huaihe River.
Generally, before the cold wave arrives, materials such as leaves, wheat straw, rice straw or plastic film are spread on the ground around the root zone of the flowers to keep warm, retain moisture and prevent freezing. After the late frost at the end of April the following year, these coverings should be removed.
Ridging Soil Around the Roots
When winter arrives, all the above-ground parts go dormant, but the fibrous roots are still growing slowly, such as tree peony, hydrangea, cotton rose, osmanthus, Chinese rose, etc. Soil should be ridged around the roots of these flowers, and when the plants begin to sprout in spring, the ridged soil should be dug open, and watering and fertilizing management should be carried out.
Wrapping with Insulation Materials
For some larger ornamental flowering trees, because the tree body is relatively large and cannot be pressed into the soil or covered, methods such as wrapping with fine straw rope, wrapping with straw, wrapping with paper, and covering with plastic film can be used for cold protection; for some flowering trees with relatively strong cold resistance but afraid of cold wind, or newly planted flowering trees, the method of setting up wind barriers can be used, that is, using reed mats, tree sticks, corn stalks and other materials to build wind barriers on the west and north sides of the flowering trees. For example, cedar and dragon juniper planted and propagated in areas north of the Huaihe River can use this method for cold protection.
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 two climate zones, the warm temperate zone and the subtropical zone, with a large north-south latitude span (more than 12 degrees), and temperature changes are obvious throughout the year, with the four seasons of spring, summer, autumn and winter being relatively distinct. Here, summer is affected by the maritime climate, with southeasterly winds prevailing, and more rain; winter is affected by the Siberian cold air flow, with northerly winds prevailing, dry, and continuous cold waves. The average temperature of the coldest month of the year is below 0°C, while in areas south of the Huaihe River it is above 0°C. Annual rainfall is around 1000 mm, and it 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, starting from late November each year and lasting until early February of the following year. This season is the coldest period of the whole year. And from late December each year to January of the following year, it is the coldest period within winter, when the lowest temperature reaches about -14 to -12°C. The farming proverb "In the first and second nine-day periods, one does not reach out one's hands; in the third and fourth nine-day periods, one walks 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 attacks in winter. For flower growers, this increases the difficulty of safely overwintering home-grown flowers, especially warmth-loving flowers and foliage plants. Flowers native to tropical and subtropical regions are even more susceptible to freezing injury when grown in winter. The winter care and management of indoor flowers 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, if there is no 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 body cells, the concentration of body cell sap increases, osmotic pressure rises, and the freezing point drops, so they can resist the invasion of low temperatures 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 easily frostbitten or even frozen to death. Different flowers have different temperature requirements in winter. To know 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, and high-temperature-tolerant flowers are also 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 category: such as poinsettia, gloxinia, Brazilwood, 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 category: 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 lowest temperature in the Guangzhou area in a year is about 1°C, so in the East China region the minimum indoor temperature in winter should not be lower than 5°C.
③ Low-temperature category: such as osmanthus, kumquat, plum, pomegranate, etc. These flowers are all cultivated in courtyards in central China and southern East China. The lowest 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) Overwintering management of home-grown flowers: In the East China region, in winter, for some potted flowers native to the tropics and subtropics, it is very important to take necessary freeze-proofing and warmth-preserving measures. For example, many families like to grow Aglaia odorata, clivia, Chloranthus, hibiscus, rubber tree, Brazilwood, cyclamen, gloxinia, jasmine, etc., as well as succulent and juicy flowers, all need to be moved indoors or into warm sheds successively in late autumn. How can one ensure that home-grown southern flowers overwinter safely? The following measures can be taken:
First, grasp the characteristics of the flowers and place them by category. The overwintering 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, and most flowers cultivated indoors are in a dormant or slow-growing semi-dormant state. For flowers that go dormant in open ground, such as tree 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 places, and generally can overwinter naturally. If attacked by a cold wave, they can be covered with plastic film to keep warm, 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 keeping the room temperature above 5°C also allows them to overwinter safely. For flowers that continue to grow in winter, such as cineraria, primrose, cyclamen, asparagus fern, etc., generally keeping the room temperature at 8-10°C allows natural overwintering, and if a cold wave occurs, warmth-preserving measures should be taken. For a small number of flowers from the tropics and flowers that need to be cultivated in winter for holiday viewing, such as tropical orchids, poinsettia, pothos, Brazilwood, 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 allow home-grown tropical flowers to overwinter safely, indoor heating or other measures are needed to raise the room temperature.
Second, carry out 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 replenishment of water is one of the important guarantees for safe overwintering. Watering indoor flowers should likewise follow the principle of watering potted flowers by alternating dry and wet periods. As for 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 watering should be flexibly controlled according to the category of the flower, the amount of water required at its growth stage, the texture of the flowerpot, etc. Generally, water once every 7-10 days. In addition, one should learn to water by observing the flowers. So-called observing the flowers means grasping the characteristics of the flowers and not applying one uniform rule to all. For example, moisture-loving flowers such as umbrella plant, spider plant, Monstera deliciosa, schefflera, etc. should be watered more; drought-tolerant flowers such as Christmas cactus, Brazilwood, sago palm, cactus types, etc. should be watered less; evergreen foliage flowers can be watered by spraying the leaf surface.
Third, keep warm and protect against cold according to category, and increase light. Temperature management during the overwintering period of potted flowers should be treated differently according to the growth state of the flowers and their different temperature requirements. If they are placed under the same temperature condition, it is inevitable that some flowers that can adapt will grow well, while others will not grow well because they cannot adapt. If high-temperature flowers are placed in a low-temperature environment, freezing injury will occur or they will even be frozen to death. However, if some low-temperature-loving flowers are placed in a high-temperature environment, their growth the following year will be affected. This point is often not taken seriously by people. If low-temperature-loving flowers are kept in a high-temperature environment for a long time in winter, they will consume excessive nutrients and this 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. Low-temperature flowers should be placed in a north-facing room, but need to be regularly moved to a sunny room to be exposed to the sun; medium-temperature flowers should be placed in a south-facing room or an enclosed balcony, and if a cold wave occurs, appropriate warmth-preserving measures are still needed; high-temperature flowers not only need to be placed in a south-facing room, but also need to have their temperature raised, keeping the indoor temperature above 12°C.
① Winter cold protection for indoor potted flowers: Most potted flowers are not native locally, and are mainly tropical and subtropical evergreen flowers. Because they are not suited to the natural conditions of their adopted location, they need to be moved indoors or into a greenhouse for care in winter. As far as the East China region is concerned, from north to south, the time for entering the greenhouse differs slightly: in the Huaibei area it is about mid-to-late October, in the Nanjing area it is mid-November, and in mid-to-late April of the following year they are successively moved outdoors.
During the overwintering 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 the flowering trees. In winter, the outside temperature is relatively low, and most flowers cultivated in cold rooms are in a dormant or slow-growing semi-dormant state. For flowers dormant in winter, such as Chinese rose, chrysanthemum, tree peony, hydrangea, etc., generally placing them in a cold room at 3-5°C allows them to overwinter safely. For flowers in a semi-dormant state in winter, such as ornamental citrus, azalea, gardenia, plum blossom, clivia, crinum lily, camellia, etc., although their temperature requirements are slightly higher, generally placing them in a cold greenhouse at 5°C or below also allows them to overwinter safely. Such temperature conditions can basically meet the requirements in areas south of the Huaihe River usually without heating. 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 8-10°C or above, which requires indoor heating or heating facilities. For a small number of flowers from the tropics and flowers that need to be cultivated in winter for holiday viewing, such as tropical orchids, poinsettia, cyclamen, tuberous begonia, Monstera deliciosa, etc., a temperature of 15-17°C or above should be provided. In areas south of the Huaihe River, there is generally no heating indoors in winter, so flowers must be placed in a room with dedicated heating facilities or in a south-facing cold room.
During the overwintering period, the level of room temperature has a relatively large impact on potted flowers. For example, warmth-loving flowers such as jasmine, poinsettia, Aglaia odorata, croton, etc., when placed in a cold environment with a 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 be in a semi-dormant state with stagnant growth and yellowing leaves and withered branches; when placed in a relatively warm environment at around 15°C, they barely sprout and unfold leaves, grow slowly, but cannot form buds and bloom.
Once potted flowers are moved 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 a corner of a room with a relatively low temperature to keep them dormant; for warmth-loving evergreen flowers or those still growing in winter, they should be placed as close as possible to a south-facing window 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 and wither and drop leaves, or even die. When the cold winter months of the twelfth lunar month arrive, use paper strips or soft foam plastic strips to seal door and window gaps against wind. In the evening, add door curtains and window curtains to the room where potted flowers are placed, so that the indoor temperature is at least 3-4°C higher than outdoors. Usually, closely monitor changes in indoor and outdoor temperatures to avoid temperature loss of control and cause undue harm to the flowers. For flowers that truly have difficulty overwintering in a cold room, the following methods can be used:
Make a flower insulation cover: For Aglaia odorata, white orchid, jasmine, etc., first use galvanized wire to form an arched ring support along the pot rim, then cover the plant together with the pot with 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, has a remarkable warmth-preserving effect, and can enhance the cold resistance of the 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 freezing injury.
Use nested pots to preserve warmth: For some flowers, such as Aglaia odorata, clivia, Chloranthus, etc., an outer pot can be added outside or under the pot to maintain temperature. The specific method is: use a slightly larger flowerpot, fill it with some insulation material or put soil in it, and embed the pot containing the flower into the large flowerpot; the potted flower can also be stacked on top of a flowerpot with soil, so that the potted flower is off the ground. This method can also play a role in preserving warmth.
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 movable doors that can be opened and closed. The box can be divided into upper and lower compartments. The dividing layer and the shelf board should use wire mesh boards to facilitate the upward release of heat. Two electric lamps should be installed at the bottom of the box. The wattage of the bulbs depends on the internal volume of the box, and it is generally 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 has high expenses and high cost, and a simple small greenhouse made of plastic film can also be used instead.
In addition to the above warmth-preserving 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 some move them outdoors to bask in the sun. These practices are all incorrect. The correct method is: first place them in a slightly warmer room and let them recover slowly, 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 injury often does not occur in winter when the temperature is lowest, but mostly appears in early spring when the temperature begins to rise. The reason is: when flowers move 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 injury. 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 weather 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 5-8°C or more. After most flowers have been cultivated indoors through the long winter, the plants 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 the flowers out of the room too early. If at this time they encounter late frost, a cold wave or cold air invasion, even if the temperature is not too low, the flowers will suffer freezing injury because they cannot adapt to changes in the external environment. Therefore, experienced flower growers all understand the principle that potted flowers should not be moved out in spring too early.
Before potted flowers are moved out, indoor ventilation should be strengthened. The doors and windows can first be opened during the day when the temperature is relatively high and closed 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 ability of potted flowers to adapt to the outdoor environment. After a period of adaptive training, overwintered potted flowers can gradually reduce their indoor care time and be safely moved out at the proper time. The specific time for moving potted flowers out should be determined in order according to the cold resistance of each type of flower. For example, osmanthus, Chinese rose, plum, etc. can be moved out when the daily average temperature reaches about 10°C, while flowers such as Aglaia odorata, hibiscus, jasmine, etc. should be moved out later. After the last cold wave passes and the daily average temperature stabilizes at around 15°C, it is much safer to move them outdoors.
② Winter cold protection for balcony flowers: Modern urban population density is increasing, and multi-story and high-rise buildings with complete functions create a comfortable living environment for people. Adapting measures to local conditions and using balconies to grow flowers can give people aesthetic enjoyment. Moreover, balcony flowers along streets directly form a scenic line of the city, and are beneficial in reducing noise, preventing pollution, adding interest to life, and purifying and beautifying the city.
Here we mainly discuss some flower-growing knowledge for balcony flowers in winter. Modern residential balconies are of 2 types: one is enclosed at the time of construction, such as most high-rise buildings and a small number of multi-story buildings; the other is not enclosed, such as most multi-story buildings that still have open balconies.
Cold protection for flowers on enclosed balconies: In winter, an enclosed balcony can play the role of a greenhouse and has a certain effect of preserving and increasing warmth. Some warmth-loving medium-temperature flowers cannot overwinter safely outdoors, but on an enclosed balcony they are basically not subject to freezing injury. 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 overwinter safely when placed on an enclosed balcony.
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 prevail and the 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 an open balcony, especially in areas north of the Yangtze River. The south balconies of multi-story buildings are mostly open. Because they are sheltered from the wind and face the sun, the freezing injury or cold injury to flowers is far less prominent and serious than on north balconies, so in winter flowers are generally placed on south balconies to overwinter. Some relatively cold-resistant flowers need only slight management on a south balcony to usually pass through winter safely, such as woody types like Chinese rose, nandina, banana shrub, gardenia, dwarf peach, winter jasmine, wintersweet, crabapple, osmanthus, pomegranate, plum blossom, tree peony, kumquat, etc., and herbaceous and perennial types such as chrysanthemum, tuberose, tulip, orchid, canna, amaryllis, etc. But open balconies have strong winds and low air humidity, and the pot soil dries out extremely easily, so the flower varieties selected must be suited to this environment. They need to be drought-tolerant and low-temperature-tolerant, and close attention must be paid to changes in the dryness and wetness of the pot soil. Watering too frequently is not good, and not watering at all is also not good. Some varieties in a dormant period can be watered less; some evergreen varieties can have the watering frequency appropriately increased, and water can also be sprayed on the leaf surface frequently. Bulbous, tuberous and perennial flowers are relatively drought-tolerant and can be watered less, such as amaryllis, tulip, canna, iris, bletilla, tuberose, Chinese peony, pink reineckea, Japanese rohdea, dianthus, chrysanthemum, etc. When attacked by a cold wave, preventive measures are still needed. A simple temporary warmth-preserving frame can be set up on the balcony, with plastic film stretched over the outside of the frame. In areas north of the Yangtze River, double-layer plastic film can be used. A plastic film cover can also be used to cover the entire potted flower to achieve the effect of warmth preservation and cold protection. In addition, some warmth-loving flowers can be temporarily moved indoors to prevent freezing injury.
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 flowering trees are highly adaptable, such as chrysanthemum, petunia, stock, red woodsorrel, daylily, tree peony, flowering quince, Chinese rose, etc. But there are also some flowers such as dahlia, canna, banana shrub, plantain, osmanthus, etc. that, although having a certain ability to resist the cold, are not tolerant of low temperatures. In areas north of the Yangtze River, protection still needs to be strengthened in winter to ensure the flowers survive the winter safely. The following methods are often used for cold protection of open-ground flowers:
The 1st 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 stage of growth. At this time, nitrogen fertilizer application should be controlled, more phosphorus fertilizer and potassium fertilizer should be applied, and the amount of watering should be moderated, so that the plants grow solidly and their resistance to cold is enhanced. After entering the winter dormancy period, cultivate and fertilize once, and barnyard manure, dung or cake fertilizer, etc. can be applied to increase the concentration of the soil solution and enhance the cold resistance of open-ground flowers.
Some perennial flowers and biennial herbaceous flowers, such as Chinese peony, canna, dahlia, tulip, edgeworthia, etc., are prone to freezing injury when overwintering naturally in areas north of the Huaihe River. If a cold wave arrives, 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 widely used, and can be removed after the late frost.
The 2nd method, ridging soil around the roots for overwintering and freeze prevention: Some flowers have all their above-ground parts go dormant when winter arrives, with only the fibrous roots still growing slowly, such as tree peony, hydrangea, cotton rose, etc. Soil can be ridged around the roots of the flowers to form a small mound. When the plants begin to sprout in spring, the ridged soil can be dug open.
The 3rd method, wrapping with insulation materials for cold protection and overwintering: For some larger ornamental flowering trees, because the tree body is relatively large and cannot be pressed into the soil or covered, methods such as wrapping with straw, wrapping with paper and covering with plastic film can be used for cold protection; for some flowering trees with relatively strong cold resistance but afraid of cold wind, or newly planted flowering trees, the method of setting up wind barriers can be used, that is, using reed mats and other materials to build wind barriers on the west and north sides of the flowering trees. This method is often used for cold protection when planting cedar in areas north of the Huaihe River.
(4) Winter water management of 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. The following 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 overwinter safely. People often attribute flower death caused by improper watering to improper warmth preservation, 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 pot soil remains in a highly wet state for a long time, it will inevitably cause root rot. Therefore, attention must be paid to watering time, watering amount and watering method, etc.
Watering time and water amount for flowers in winter: Because ground-planted flowers have relatively well-developed root systems, they generally do not need watering in winter. They can be watered sufficiently after leaf drop and before the soil 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 the temperature gradually drops. At this time, leaf transpiration and soil surface evaporation decrease accordingly. In the north, most potted flowers are moved indoors to overwinter. Overall, the pot soil should mainly be on the dry side, maintaining a humidity of about 30%, that is, the pot soil being moist is enough. Special attention should be paid to the amount of watering from December to January of the following year, because this period is the relatively cold time in North China in winter. 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 pot soil truly needs watering, generally watering once every 1-2 weeks can meet the need. For a small number that need a large amount of water, such as foliage plants, water once every 4-5 days, and absolutely do not water too frequently. Usually, more water can be sprayed on the leaf surface to reduce the number of times water is applied to the pot soil. Some home flower growers, as soon as they see the surface of the pot soil looking a bit dry, think the flowering plant is short of water. In fact, in winter, this situation does not matter, because although the surface of the pot soil looks a bit dry, the lower layer of soil is still moist. Flowers in winter need very little water. As long as the pot soil has a certain humidity, the flowers will not die. For relatively large plants, because they themselves need a large amount of water and have relatively strong stress resistance, 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 pot soil is completely dry. In short, watering flowers in winter should favor dryness rather than wetness, mainly by spraying water on the leaf surface, and reducing watering of the pot soil as much as possible, so as to keep the pot soil on the dry side 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 first store water for watering flowers in an open container, and use it when the water temperature, air temperature and soil temperature differ little. Warm water can also be used to mix it. For evergreen potted flowers, warm water above 10°C and below 15°C can be sprayed on the leaf surface, which not only achieves the purpose of watering, but also prevents the harm of dry freezing to the flowers. If cold water is used to water flowers in a low-temperature environment, the low air temperature and low water temperature will aggravate the harm to potted flowers. Flowers in winter 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 in water and let the water slowly seep in along the hole at the bottom of the pot. When the surface soil becomes wet, take the potted flower out. This method can make the soil absorb water sufficiently and is relatively ideal. Moisture-loving flowers such as umbrella plant and calla lily need a relatively large amount of water 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 watering can to turn water droplets into mist and spray it on the leaf surface of flowers, such as asparagus fern, spider plant, Western azalea, schefflera, rubber tree, cineraria, clivia, etc. The mist spraying method can not only give the leaf surface and the area around the pot relatively high humidity, but also keep the leaf surface 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 contains bleaching powder, liquid chlorine, alum, etc., and long-term use will make the pot soil alkalized and hardened, so 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 diseases and insect pests of flowers: There are generally fewer diseases and insect pests in winter, but some diseases and insect pests also appear in rooms with heating or higher temperatures. This not only affects the healthy growth of flowers, but also affects their ornamental value, so attention must be paid to the prevention and control of diseases and insect pests. Generally, households mainly focus on prevention, maintaining suitable temperature and humidity, good indoor ventilation, and suitable soil dryness and wetness. When sowing, the soil must be disinfected, and when selecting strong seeds or introducing flower seedlings, they should not carry diseases and insect pests. These are all effective measures to prevent diseases and insect pests.
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, rainy season from June to August. A small number of diseases and insect pests also occur in winter.