How to treat rhododendron frostbite

Although cuckoos like to be cool, moist and afraid of heat and dryness, frostbite may also occur when buying flowers in winter or during maintenance. In this case, you can deal with it in the following ways:

When the temperature drops below 0 degrees Celsius, there will be a thin layer of ice outside the flowerpot, the surface of the pot soil will also be frozen, and the leaves will be frozen hard. At this time, you must not be in a hurry. You can put the flowers in a room of about 5 degrees Celsius. After 12 hours, the frozen soil will slowly melt, the leaves will return to normal, and the frostbitten shoots and small tender leaves will be light brown, which will not affect their growth. After normal management, the new shoots will still grow into buds. It's just that the edges of flowers that bloom after frostbite become lighter. Someone is eager for success, put the flower directly in the warm room, want it to recover as soon as possible, but send it to the road of no return.

If you are frozen by the cold wind on the way to buy flowers in winter, you can also deal with them according to the above method. An aspirin (30 cm in crown diameter according to plant size) can also be dissolved in water and poured into the basin soil, which is equally effective.

Use low temperature to treat cuckoos with frostbite, the temperature difference should not be too large, within 10 degrees Celsius is better, this and the treatment of frostbite patients with snow rub is the same reason.

How to treat the frostbitten rhododendron

How to treat cuckoo frostbite? although cuckoos like to be cool, moist and afraid of dryness and heat, frostbite may also occur when buying flowers in winter or in maintenance. In this case, we can deal with it in the following ways: when the temperature drops below 0 ℃, there will be a thin layer of ice outside the flowerpot, the surface of the basin soil will also be frozen, and the leaves will be frozen hard. At this time must not be urgent, can put the flowers in a room of about 5 ℃, after 12 hours, the frozen soil will slowly melt, the leaves will return to normal, frostbitten shoots and small tender leaves are light brown, do not affect the growth, after normal management, the new shoots are still long leaves pregnant buds. It's just that the edges of flowers that bloom after frostbite become lighter. Someone is eager for success, put the flower directly in the warm room, want it to recover as soon as possible, but send it to the road of no return. If you are frozen by the cold wind on the way to buy flowers in winter, you can also deal with them according to the above method. Can also be a piece of aspirin (according to the plant size, according to the crown diameter of 30 cm) dissolved in water and poured into the basin soil, equally effective. Using low temperature to treat rhododendron with frostbite, the temperature difference should not be too large, and it is better within 10 ℃, which is the same reason as using snow to rub patients with frostbite.

Prevention and treatment of chilling injury of ornamental plants

1. Prevention of chilling injury of ornamental plants:

(1) choose more cold-resistant flowers: flower lovers should choose flowers and trees for foliage, flowers or fruit according to the minimum temperature in a normal year in your area or the maximum room temperature that can be maintained in winter (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) to carry out cold resistance exercise in stages: generally potted five-needle pine, black pine, red pine, Huangshan pine, papaya, elm, maple, plum blossom, camellia, ginkgo, dragon cypress, Platycladus orientalis, Sabina vulgaris, etc., may consider 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, with 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 ℃, in which the fine structure and enzymes in the protoplast are recombined so that the cells can tolerate dehydration caused by freezing.

The third stage is between-10 ℃ and-15 ℃, which makes the protoplast have strong freezing resistance 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 ℃.

(3) strengthen cold-resistant cultivation management: 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 branch Lignification and tissue development, 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) Anti-freezing protection of trees: for tall camellia, sweet-scented osmanthus, Michelia, Magnolia, Canadian jujube, cycads, etc., the trunk can be bound with grass rope or film, the trunk can be white or the crown is white (7% 10% lime milk); the crown mask is bound with plastic film, and can also be sprayed with wax or liquid plastic, which can have a certain anti-freezing effect.

(5) artificial heating and dispelling cold: potted plants shelved in the greenhouse can be heated by 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) postponing germination and preventing late frost: using growth regulators or other methods to prolong plant dormancy and postpone 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 no re-pruning should be carried out, otherwise harmful side effects will occur. 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 the wound: for the thick flowers and plants that are frozen only on the dry base (northwest), the necrotic part can be gouged out, the wound healing agent can be smeared, and then protected with thin film to create a warmer small environment for it; for some damaged bonsai plants, they can be remedied by bridging or changing roots.

(3) strengthen the prevention and control of diseases and insect pests: after suffering from low temperature, ornamental plants are extremely 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) prudent fertilization: for freeze-damaged plants, high concentration chemical fertilizer should not be applied immediately after overwintering, but should be sprayed or poured with low concentration liquid fertilizer after the temperature rises and the root system resumes its absorption function. If 0.3% potassium dihydrogen phosphate and 0.3% urea solution can be used, the effect is very good.

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