How to raise reticulate grass in winter, four tips to avoid leaf wilting / temperature is very important.

Because of the general cold tolerance of reticulate grass, how to survive the winter has become a headache for many flower friends. If the method is wrong, it is easy to cause the leaves to wither and fall, then the efficacy and function of reticulated grass will be greatly reduced, and how to raise it in winter? The following editor will tell you some of the most practical skills.

How to raise reticulate grass in winter

1. Light intensity

The grass is exposed to direct sunlight, but in winter, it can be exposed to sunlight for a period of time, which not only increases the ambient temperature, but also keeps its leaves green. If it is a warm winter, you need to pay attention to temperature changes.

2. Suitable temperature

The reason why reticulate grass has always been very popular is that its veins are very special, but if the winter temperature is lower than 8 degrees, it is easy to die, and if it is below 12 degrees, it may freeze, so it must be kept warm indoors in the north. And the south should also keep warm.

3. Appropriate watering

Because the grass is afraid of drought, once the soil is too dry, its leaves will curl and fall off, but the soil must not be too wet in winter, otherwise it is not conducive to temperature control, so it is usually watered every 7-10 days. Keep the soil slightly moist, the method can refer to the detailed description of how to water the grass.

4. Stop fertilization

Fertilization is usually applied 1-2 times a month in other seasons, but how to raise grass in winter? The answer is to stop fertilizing. The growth rate of reticulate grass determines whether we need to apply fertilizer, but its growth basically stops in winter, so fertilization should also be stopped.

Matters needing attention in raising net grass in winter

1. Do not breed. Although the reproduction of reticulate grass is very easy, but because the temperature in winter is relatively low, no matter which way is adopted, it is more difficult to take root, and the survival rate after reproduction is also low, so it is best to choose the spring when the temperature is more suitable.

2. Do not change the basin. Generally speaking, the grass needs to change the soil of the flowerpot regularly, but do not change the pot in winter, because it takes a period of time to slow down the seedlings after changing the pot, and the winter temperature is very unfavorable for it to adapt to the new environment.

3. Clear the fallen leaves. Some aging leaves will fall in autumn and winter, and some leaves may fall early in the flowerpot because of improper maintenance. Be careful to clean up these fallen leaves in time and do not let them mix into the soil, otherwise they will pollute the soil.

4. No pruning. In winter, reticulate grass will go into a dormant state, it basically will not sprout new buds, and one of the main purposes of pruning is to promote plant germination of new branches, if pruning in winter obviously can not achieve this goal, so winter is not suitable for pruning.

Why can't you raise indoor plants well?

Have you ever passed a flower shop and happily brought home a delicate plant, or put it at your desk, but it withered a little bit as if it had been enchanted?

No matter how much you take care of it, you can't reverse the end that it will die in the end. you go to the florist again, only to find that you are in vain and say you will never raise plants again. But can not get rid of the love of plants, in fact, plants have her temperament.

Influencing factors

I. Environment

Indoor ventilation is generally not particularly good, especially in summer and winter, turning on air conditioning and heating will not open windows for ventilation, and the humidity and temperature of the room will be changed while using air conditioning. Coupled with the influence of indoor lighting and other environmental factors, plant growth is often inhibited and easy to yellowing until slowly die.

The temperament of plants also shows that they also need partners, which is one of the reasons why plants in the greenhouse grow better than those in the office or home. Due to the large number of plants in the greenhouse, it can create a special environment for plant growth, which plays a role in promoting plant growth.

II. Character factors

1. Continuous watering

Plants are very taboo to water in this way, the ventilation and light are worse than outdoor, resulting in moisture in the soil can not be volatilized, resulting in stagnant water rotten roots yellowing all kinds of uncomfortable phenomenon.

2. Be touched frequently

It will cause damage to green plant leaves or leaf buds, which will not only affect the normal growth of plants, but also unsightly.

III. Plant self-factors

1. Normal metabolism of yellow leaves

The bottom or individual old leaves are withered and yellow, and the new leaves and most of the leaves are healthy. For example, green turnips occasionally have two yellow leaves at the bottom, as long as they are removed and thrown away, there is no effect to worry about.

2. Diseases and insect pests

In fact, plants, like our bodies, are easy to get sick. We need to go to the hospital for regular check-ups, and so do plants.

Specific analysis of common symptoms

Symptom one, the leaves are yellow, the leaves are falling, and the plants are dying.

Consultation

It may be caused by three reasons: the place where the plant is placed is too dark and lacks the basic light; it is watered too frequently, resulting in rotten roots; and the planting soil remains unchanged for many years and lacks the necessary nutrients.

Solution

Change the position, put it by the window or in a sunny place, let it be exposed to light for a period of time; stop watering until the pot soil is dry; buy small bottles of green leaf fertilizer from the flower market and apply it to the soil.

Symptom 2. The newly growing stems and young leaves are very sparse.

Consultation

Because of the serious lack of light, the old leaves wither and the new leaves are thin and sparse, which has a special term in horticulture called "overgrowth".

Solution

Choose shade-tolerant plants that are suitable for indoor growth, or you can choose a special ultraviolet lamp to supplement the light for the plant (this lamp is not recommended for beginners).

Symptom 3. Flowers wither and stems wither.

Consultation

Lack of water. Indoor plants are left unattended, and some flowering plants that need daily water will wither. In addition, lack of light is also a problem.

Solution

There is a very simple way to put a plate full of water under the flowerpot when there is no leisure management.

Symptom 4. Flowers and plants dry up and die.

Consultation

Indoor green plants usually produce few insects, and flowering plants such as chamomile usually have worms before they settle in the office (that is, they are likely to have bugs by the time they are bought).

Solution

It needs to be sprayed with insecticides and exposed to sunlight, which is not suitable for indoor environment and must be done outdoors. But this may take up time, so it is basically not suitable for raising flowering plants indoors, which are more prone to insects than green leafy plants, and are not recommended.

Symptom 5. Leaves turn yellow first and then black.

Consultation

After the leaves turn yellow, remove the diseased leaves once, or then turn black, and the leaves are still watery two months ago, which can be identified as plant air-conditioning disease.

Solution

Too much water, lack of elements, bacterial diseases, but mainly under the air conditioning, affecting the normal growth of plants, plants are still relatively healthy, can be sprayed to add insecticides.

Symptom 6. White things on potted plants, small insect pests

Consultation

This is caused by scale insects.

Solution

One of Lexben, acephate and chlorpromazine can be sprayed with water 2-3 times as described, once every 10 days.

Specific solutions to common plant symptoms

Peace tree

Symptom

The leaves wilted and gradually yellowed and dried.

Method

When watering, it is important to see whether the basin bottom is leaking and whether the soil is ventilated or not. Thin wire can be inserted along the edge of the basin to help breathe. See if the soil is dry or wet. Dryness means that your plant has been out of water for too long and needs to be watered until the basin leaks. Dampness means that you are overwatered and moved to a ventilated position to help water evaporate. Of course, frostbite should be prevented now.

Make a fortune tree

Symptom

The leaves turn yellow and lose the leaves.

Method

Rich trees like places where there is plenty of heat and sunshine, not in shady places for a long time, but in places with plenty of light; rich trees belong to drought-tolerant plants, so they should not be watered too frequently and cannot accumulate water in the basin; see if the roots are rotten. If the roots are rotten, they should be removed, disinfected with carbendazim or potassium permanganate and replanted. If your planting soil is clayey, it can be mixed with some river sand.

Africa Jasmine

Symptom

The leaves withered and fell

Method

The light is too poor, so we need to move it to a place where the sun is better. Of course, watering the flowers with tea will wilt and the leaves will fall, so we must water them with clean water instead.

Rich bamboo

Symptom

The yellow leaves are always falling and the branches are withering.

Method

Put in shade environment for a long time, the leaves can not get enough sunlight, can not form chlorophyll, the whole leaves turn yellow and then fall off, supplementary light can avoid the disease. Check the basin soil, if there is a dry phenomenon should change the soil, usually apply thin fertilizer frequently and timely pour some alum, rich bamboo is foliage plants should be nitrogen-based fertilizer.

Hyacinth

Symptom

Rotten root

Method

If it is hydroponic, the water level should just reach the root plate, and after the root grows, the water level should be lower than that of the root plate; for hydroponic hyacinths, the water must be changed regularly to keep the water clean; hydroponic hyacinths do not need to use nutrient solution; if it is only rotten roots, the sphere is fine, clean the rotting roots, and then disinfect them with potassium permanganate and dry them in a ventilated place. Re-planting, as long as the root plate is not bad, the chance of saving is still very high. If the sphere is also moldy and rotten, first clean the moldy place, peel off the rotten place, and check the surrounding ball for signs of decay, and finally disinfect, dry and replant (soil cultivation is recommended).

Kumquat tree

Symptom

Dry and withered

Method

The ambient temperature of the golden orange tree should not be lower than 8 degrees; it should be loose and fertile. The soil with good aggregate structure has a large porosity, which is conducive to the discharge of excess water and contains enough air; keep the soil moist, but not too moist, do not accumulate water, otherwise it is easy to rot the roots; water should be watered in the morning or evening in summer and when the temperature is warmer at noon in winter. It is best to use Rain Water to water, or river water, if it is to use tap water, it should be left for a few days before watering.

Reticulate grass

Symptom

The leaves wilted.

Method

It is possible that the root was hurt when it was just planted, wait for a while; the grass should be properly exposed to the sun; most of the leaves of the grass wilt because of lack of water, so we pour some water and water through it, and then we can put it in the sun. Remember that many plants can not be put next to the heating, and the reticulate grass is no exception, and do not put it in a place that is too cold. If it is too cold in winter, you can cover a plastic bag at night and take it off during the day.

Crab claw orchid

Symptom

Do not bloom

Method

Less nitrogen fertilizer, containing more nitrogen fertilizer, if applied too much, it will make the vegetative growth too exuberant and inhibit reproductive growth. At this time, crab claws will appear do not like to blossom. Crab claw orchid can blossom smoothly only under the light condition of short day and long day. When the crab claw orchid grows slowly in the low temperature environment below 15 ℃, it is easy to cause the dumb bud phenomenon of flower bud death. In addition, when the ambient temperature drops to about 0 ℃, the buds will freeze and die. Therefore, the temperature must be kept at 15-20 ℃ to ensure the normal development of flower buds. Every spring, it is best to cut off part of the older crab claw fleshy stem with changing pots, and carefully knock out the plant from the flowerpot, and use a sharp knife to remove a layer of old root from the surface of the soil block to promote the new root, so that the plant's fertility is increased and the growth potential is stronger. Naturally, there are more flowers.

Comprehensive maintenance method

1. Watering should be moderate

Because the indoor air circulation is poor, the water transpiration in the flowerpot soil is small, and the pots used by green plants are often considered from the aesthetic point of view, and porcelain pots are used more often. This kind of basin is airtight and impervious to water, which reduces the water loss of the basin soil. Therefore, it is necessary to control the amount of water as much as possible, otherwise it is very easy to make the roots of green plants rot after long-term immersion in water.

2. Maintain humidity

Plants are more sensitive to air humidity than we are. Potted plants cannot adapt to overheated and dry air, and it is easy to make some pests more rampant. To maintain the humidity of potted plants, you might as well take the following measures:

① uses humidifier

② put the plants in the same place

③ places plants on trays filled with water and pebbles (water is best not to drown pebbles)

When using air conditioner for a long time, ④ sprays water on the leaves properly to meet the water demand of green plants.

3. Give the plants a bath

"bathing" plants (flushing plants with hoses or sprinklers) can get rid of many pests. Bathe the plants in late autumn and get out of the dust on the leaves. Pay attention to the washing process should not be too fierce, so as not to damage the branches and leaves. At the same time, care should be taken not to bruise the plants during flushing.

4. Consider the light demand of green plants.

In plant maintenance, we should pay attention to the location of plants, light-loving plants should be placed in places with sufficient light as far as possible. If there is not enough light, the position can be changed frequently to allow plants to enjoy adequate photosynthesis at regular intervals.

5. the basin should be changed in time.

Unless the roots of potted plants extend without ground, there is no need to change pots. It is best to choose the early spring season to change the basin. At the same time, attention should be paid to watering the basin once before changing the basin according to the situation, and then change the basin when the soil is moderately dry and wet.

Identification and Prevention of freezing injury of Flowers and trees

When potted or planted flowers and trees suddenly encounter a cold wave and go south in late autumn and early winter, or because of the sudden arrival of the "first frost", it is easy to cause flowers and plants to suffer cold injury or frost injury; when potted flowers leave the room or facility cultivation in spring to remove the covered film, suddenly encounter the belated "late frost" or "late spring cold", it is also very likely to cause the flowers and plants to suffer cold injury or frost injury again. Whether it is large-scale productive cultivation, or a small number of potted plants by flower lovers, great attention must be paid to the prevention of cold injury, otherwise it will bring you serious losses and long-term "remorse".

Cold injury is a kind of physiological disease, which is not an infectious disease caused by pathogenic bacteria. It generally refers to the injury caused by the direct action of low temperature on flower plants, including cold injury and freezing injury, but does not include indirect winter drought, freezing and other winter injuries.

Winter drought and freezing are indirect damage caused by low temperature. Winter drought refers to: some evergreen flowers, under some special weather conditions in winter, such as long-lasting and strong wind sweeping or sunny days that are not too cold but sunny, the transpiration rate is relatively high, but because the soil temperature is low and the root absorbs water slowly, the water in the body can not maintain a normal balance, so that leaves and other tissues are dehydrated, dried and damaged, which is essentially a kind of drought damage. Such as wood incense, Jasminum and other leaves suddenly dried up in dry, cold and sunny days. Frozen pull refers to: when the water of melting snow seeps into the soil and freezes again, some plants, especially seedlings or herbaceous flowers, are often lifted together with the frozen soil, thus destroying the close contact between the root system and the soil, or even tearing off the root group; before the root system has time to recover, it encounters weather conditions that promote strong transpiration, causing the plant to wither and die. If the wintersweet planted in the flowerpot is placed in a very cold place in winter and freezes because the pot soil is wet, lift the root block to separate it from the basin wall, if it can not be found in time, and replant it, or move it to a warmer environment, it is also likely to die due to the loss of water in the root system, resulting in plant death.

I. types and causes of cold injury

As the causes of cold injury are different, the harmfulness is also different. The difference between cold injury and general infectious diseases lies in: first, it is not contagious, the injured site will not appear pathogens; second, the same kind of flowers and trees placed in the same environment tend to have diseases at the same time overnight, and young shoots and new leaves are the most serious. Third, it occurs in low temperature or very cold weather conditions, and the harmfulness is related to the types of flowers and trees, the duration of low temperature, the speed of temperature recovery, the lower limit of low temperature and so on.

Bamboo taro chilling injury poinsettia chilling injury pocket turtle back bamboo chilling injury petunia chilling injury concomitant fruit taro chilling injury Marianne powder leaf chilling injury

1. Causes of chilling injury

Some ornamental plants native to the tropics or subtropics are seriously damaged or killed by the low temperature above freezing point (0 ℃ ~ 5 ℃ or higher) for a few days or even only a few hours. This kind of cold injury, which does not reach the degree of freezing in the tissue, is called "cold injury". It is caused by the disturbance of normal metabolism in cells and tends to be disordered, resulting in the production of toxic substances. Different physiological activities and metabolic processes of flower plants have their own highest, lowest and optimum temperatures. when the environmental temperature changes, their physiological activities and metabolic processes will be affected differently; if beyond a certain range, it will destroy the coordination between them and produce a large number of substances that will not be produced and accumulated under normal conditions. Further study found that under the condition of chilling injury, the rate of protein hydrolysis was 4 / 9 times higher than that under normal conditions, and the metabolism of nucleic acid was seriously interfered. In addition, cooling also affected the oxidation activity of sensitive mitochondrial membrane in plant somatic cells.

Thus it can be seen that: first, the species of ornamental plants that cause chilling injury are usually plants native to the tropics or subtropics; second, the temperature condition of chilling injury is higher than that of freezing point; third, the time of causing chilling injury is long and short, usually a few days, or even just a few hours. Generally in late autumn and early winter or early spring, sudden changes in temperature are most likely to lead to chilling injury to flowers and foliage plants originating in the tropics or subtropics. Usually the young leaves of the tender shoots are "purple", "brown", "yellowing", "wilting", "necrotic" and so on, such as a string of red, green bamboo leaves, longevity flowers, leaf cotyledons, purple bamboo leaves, and so on, all belong to this category.

Helios chilling injury, safflower chilling injury, little angel chilling injury, mosquito repellent weed chilling injury, money banyan chilling injury, green emperor chilling injury, green giant chilling injury, watermelon bark pepper grass chilling injury, water bamboo grass chilling injury, evergreen chilling injury, big leaf umbrella chilling injury.

2. The cause of freezing injury.

Freezing injury refers to the damage caused by freezing in the tissue of ornamental plants when the temperature is below 0 ℃ or when they encounter ultra-low temperature for a long time.

There are two kinds of ice crystals in plant tissue, one is freezing in cells, the other is freezing between cells. The former means that when plant tissue freezes quickly, ice crystals form in vacuoles and protoplasts, destroying the structure of protoplasts and causing protein denaturation, and some membranes in protoplasts are also scratched, usually causing tissue to be killed. therefore, the result of this "freezing injury" is very serious and irreversible. For example, the cold wave in the north suddenly went south in early winter, causing a sharp drop in temperature in a short time, and in the winter of 2004, a large number of foliage plants in southern China died of freezing injury; in early December 2005, the temperature in Hefei suddenly dropped from 12 ℃ ~ 15 ℃ to-3 ℃ ~-5 ℃, resulting in a large number of magnoliaceae flowers and trees, such as Magnolia mandshurica, Magnolia mandshurica, Magnolia safflower, Magnolia ruyuanensis and other leaves and young stems seriously frozen. The latter refers to the gradual formation of ice crystals in plant tissues with the gradual decrease of ambient temperature. because the concentration of solution in the intercellular space is generally lower than that of protoplasts and vacuoles, the cooling rate is not too fast. the water in the intercellular space reaches the freezing point and freezes first than inside the cell, and the formation of ice crystals causes the water in the protoplast to move outward. This leads to cell liquid concentration, protoplast dehydration, protein precipitation, cell membrane degeneration and cell wall rupture. When ice crystals are formed in the intercellular space, whether the cell tissue is killed depends on the freezing resistance of the cell and the speed and times of freezing and thawing; one of the mechanisms of freezing injury is the dehydration of protoplasts, which has the same consequences as dehydration under drought conditions. that is, due to the mechanical stress caused by the deformation of the cell wall, the structure of the protoplast has been irreversibly destroyed. After the cell fluid is concentrated, the concentration of salt ions and organic acids increases, which may also be toxic to the protoplasm. The serious degree of freezing injury is related to the speed of freezing, the faster the freezing, the more serious the injury, this is because the faster freezing, the greater the possibility of intracellular freezing; if the freezing is limited to the intercellular space, then the faster the freezing, the faster the water loss and contraction of the cell. the greater the destructive effect of mechanical stress. The serious consequences caused by freezing injury are also related to the rate of thawing of frozen tissue. Generally, in the case of intracellular freezing, it will inevitably lead to tissue necrosis, which has nothing to do with the rate of freezing; while in the case of freezing between cells, the faster the melting rate, the greater the harm. This is because the cell wall rapidly absorbs the water produced by melting ice and expands, but the protoplast attached to the cell wall absorbs water slowly, resulting in tearing and damage. For example, after the red bell flower and triangular plum were severely frozen, the temperature rose rapidly, resulting in the bark being torn and died.

II. Specific manifestations of cold damage suffered by ornamental plants

1. Blackening of xylem

Among the various tissues of mature branches of woody flowers, the cambium is the most cold-resistant, followed by the skin, and the xylem and pith are the least cold-resistant. Therefore, mild frostbite only showed pulp discoloration, xylem discoloration in moderate frostbite, and frostbite phloem in severe frostbite. If the cambium in the stem or branch changes color, it will lose its resilience and may lead to the death of the whole plant.

2. Cracking and necrosis of dry skin

Some flowers and trees native to tropical and subtropical regions with high water content in dried bark, such as Fusang, red bell flower, cinnamon, rich tree, big flower tiger thorn plum, golden banyan and so on. When the ambient temperature drops to about-3 ℃, not only the leaves and branches will be frozen to death, but even the outer bark of the stem, especially the root neck, will form ice crystals, cold expansion and hot shrinkage due to water in the tissue, resulting in bark cracking and necrosis, or even death of the whole plant. White orchid chilling injury purple bamboo grass chilling injury Amorphophallus chilling injury longevity flower chilling injury keel freezing injury 3, tender shoot new leaf color change one of them is "yellowing", in the cold season, because the temperature is too low, some flower leaves that require high overwintering temperature will also turn yellow or even fall off due to cold injury, such as Anthurium andraeanum, hanging branch green apple, watermelon pepper grass and so on. The second is "whitening", such as hanging orchids placed or planted in the open field, Zhu Dinghong, flower and leaf hanging bamboo plums, etc., when they encounter lower temperatures, the new shoots and young leaves will lose their original luster and appear abnormal changes of "whitening and losing green"; third, "scorched", the new shoots and leaves of some ornamental plants are "scorched" due to frost, such as Cymbidium, Junzi orchid, star anise gold plate and so on. Fourth, "purple", some ornamental plants, in the case of low temperature, the leaf tip or leaf edge "purple brown" phenomenon, such as money tree, ink orchid, camellia (new leaves) and so on. 4. Ornamental plants with high water content in leaves, shoots or stems scalded by boiling water, including some succulent plants, such as green apple, ash, mulberry, Rieger begonia, flower vine, orchid, taro, aloe, longevity flower, palm bamboo, Canadian jujube (seedling), Washington sunflower, money tree, hulk, etc., when the ambient temperature suddenly drops from 5 ℃ ~ 8 ℃ to-3 ℃ ~-5 ℃. And lasted for a long time, its new twigs and leaves, as if they had been scalded or cooked by boiling water, all died in a short time, and the dry skin cracked and peeled off. 5. New shoot young leaves brown and dead some underdeveloped ornamental plants, such as golden banyan, ten meritorious works, star anise gold plate, oleander, rich tree, Phoenix tail iron, etc., like a fire, very ugly. 6. plant necrosis hollow succulent plants, when encountered with frost injury, often lead to plant dryness and hollow, and necrosis of the whole plant. Such as cactus, cactus, unicorn, three-angled arrow and so on. 3. Prevention and treatment of cold injury of ornamental plants 1. Prevention of cold injury of ornamental plants (1) choose more cold-resistant flower species. Flower lovers should choose flowers and trees for foliage, flowers or fruit according to the lowest temperature in normal years in your area or the highest room temperature that can be maintained in winter in your home (usually 5 ℃ ~ 6 ℃). Located in the general home in the Yangtze River basin, without heating equipment, camellia, tea plum, jasmine, magnolia, gentleman orchid, Belgian rhododendron, plum blossom, wax plum, bergamot, dai dai, red palm, cycad, etc., can not choose variable leaf wood, bamboo taro, reticulate grass, desert rose, rhododendron, flutong, Phalaenopsis, Mariandai powder, taro, money tree and so on. (2) Cold resistance training in general potted plants, such as five-needle pine, black pine, red pine, Huangshan pine, papaya, elm, triangular maple, plum blossom, camellia, ginkgo, dragon cypress, Platycladus orientalis, cypress, etc., can be considered for overwintering, and it is best to carry out anti-freezing exercise in several stages after the end of their growth in the current year. The first stage is 0 ℃ ~ 6 ℃, which takes several days to weeks and is given sufficient light. Evergreen can convert starch in leaves into sugar, large vacuoles into several small vacuoles, and some fat tree species can convert starch into fat. The second stage is-3 ℃ ~-5 ℃, the fine structure and enzymes in the protoplast are recombined so that the cells can tolerate the dehydration caused by freezing, and the third stage is between-10 ℃ ~-15 ℃, which makes the protoplast have strong freeze tolerance and survive the cold winter. And some cold-resistant succulent plants, such as long-term balcony or open field maintenance, have a gradual adaptation process, such as rat tail palm, 12 rolls, sedum tree, gemstone flower and so on, which can be raised from 0 ℃ to-5 ℃ ~-7 ℃. Zhu Dinghong freeze injury Camellia, rich coconut, king coconut, coconut, aloe, aloe, goose palm wood, spring plum, plum, orchid, kumquat, butterfly orchid, beautiful needle sunflower, sweet-scented osmanthus, palm bamboo, turtle back, bamboo, anise iron, star anise, golden plate, red bell, oleander, fish-tail, palm, rich trees, cycads, dried cycads.

(3) strengthen the cultivation and management of cold resistance.

After the Mid-Autumn Festival, control the water and fertilizer supply of potted ornamental plants, appropriately increase the application of phosphorus and potassium fertilizer, promote the Lignification and tissue development of branches, and enhance their cold resistance, such as pouring or spraying 0.3% potassium dihydrogen phosphate solution. Pruning or manual removal of some leaves (such as Magnolia) in winter to reduce transpiration area can have a good effect on the prevention of low temperature injury. Strengthen the prevention and control of diseases and insect pests and promote the growth of plants without autumn shoots or tender shoots.

(4) to protect the tree from freezing.

For tall camellia, sweet-scented osmanthus, Michelia, Magnolia, Canadian jujube, cycad, etc., the trunk can be bundled with grass rope or film, the trunk can be white or the crown can be whitened (7% 10% lime milk); the crown mask can be bound with plastic film, and can also be sprayed with wax or liquid plastic, which can have a certain anti-freezing effect.

(5) artificial warming to ward off cold

Potted plants shelved in the greenhouse can be heated in the greenhouse with electric heaters or coal stoves in especially cold weather, especially in the coldest part of the day from 5: 00 a.m. to 6 o'clock in the morning. Cover the greenhouse with straw curtains or blankets to keep warm. Generally, plants can be covered with double-layer plastic bags at home; potted flowers placed indoors, if conditions permit, can turn on the air conditioner from 6 a.m. to 10:00 to avoid chilling damage to Anthurium andraeanum, Amorphophallus, Magnolia, Phalaenopsis, Oncidium, Cymbidium, Cymbidium, etc. Camellia, sweet-scented osmanthus, Michelia and other flowers and trees planted on the ground can spray water on the canopy at the dawn of frost or ignite anti-frost smoke before frosting in the morning, which can effectively prevent "radiation frost".

(6) postpone germination and prevent night frost.

The use of growth regulators or other methods to prolong plant dormancy and delay germination can avoid frost caused by cold wave in early spring. For example, spraying B9, ethephon, penicillin, potassium naphthylacetate (250mg/kg~500mg/kg), or maleic dihydrazide (0.1%-0.2%) solution before germination or at the end of autumn has a good effect. Such as potted flowers encounter "night frost" after coming out of the room. It can be covered with double-layer large plastic film and will be removed after the temperature picks up during the day.

2. Treatment of cold injury of ornamental plants.

(1) reasonable pruning

Reasonable pruning measures should be taken for plants suffering from cold injury, and heavy pruning should not be carried out, otherwise it will produce harmful side effects. So how to control the amount of pruning? It is necessary to cut the damaged organs to healthy parts to promote the renewal and growth of branches, and to ensure the relative balance of underground and aboveground organs. Generally pruning immediately after the injury, the damaged part of the branch 1cm~2cm can be retained to prevent the healthy part of the branch from drying down again; if it is pruned after the beginning of spring, it can be cut to a healthy place to facilitate wound healing; practice has proved that the recovery speed of the damaged plant after reasonable pruning is faster than that of re-pruned and non-pruned plants.

For general evergreen potted woody flowers and foliage plants, all dead parts should be cut off in time and moved to a warmer environment.

(2) protect and repair wounds

For the thick flower plants that are only partially frozen on the dry base (northwest), the necrotic part can be gouged out, the wound healing agent can be smeared, and then protected by thin film, so as to create a warmer small environment for it; for some damaged bonsai plants, it can be remedied by bridging or changing roots.

(3) strengthen the prevention and control of diseases and pests

After being harmed by low temperature, ornamental plants are vulnerable to diseases and insect pests because of their weak tree potential, so chemical agents can be applied in combination with the prevention and control of freezing injury. Among them, the effect of fungicide plus moisturizing adhesive is better, followed by fungicide and high fat film, which is better than simple fungicide or whitening agent. Because the main fungicide can only play the role of surface disinfection and sterilization, the auxiliary moisturizing viscose and high-fat film not only play the role of moisturizing, but also play the role of warming, which are conducive to the formation of frostbite callus and promote the healing of frostbite.

(4) careful fertilization

For freeze-damaged plants, high concentration chemical fertilizer should not be applied immediately after overwintering, but should be sprayed or irrigated with low concentration liquid fertilizer after the temperature rises and the root system resumes its absorption function, such as 0.3% potassium dihydrogen phosphate and 0.3% urea solution, alternately spraying or pouring, the effect is very good.