How to prevent frost of flowers in greenhouse in winter?

After entering winter in the north, there is a lot of wind and snow weather, the temperature is very low, and the greenhouse is closed for a long time, which is prone to frost injury and wind damage, so the flowers in the greenhouse need to be carefully managed to avoid the death of flowers.

Frost injury of flowers in greenhouse

Different flowers should be managed separately according to their different cold resistance:

1. Add mulch. At night, a small shed should be set up in the greenhouse and covered with straw curtains. Adding grass stalk or corn straw around the greenhouse at night can increase the temperature by 1 ℃ to 2 ℃. Adding a thin layer on top of the original grass can increase the greenhouse temperature by 2 ℃ to 3 ℃. Covering the original grass grass with a film can not only block the wind, but also prevent rain and snow from wetting the grass, thus reducing the heat loss caused by water evaporation. The flowers planted on the ground can also be covered with plastic film, and the soil temperature can be increased by more than 1 ℃ after mulching.

2. Smoke around. Before the cold spell comes, igniting smoke around the greenhouse can prevent the heat around the greenhouse from radiating to the high air and reduce the heat loss.

3. Clean the greenhouse film. Cleaning the dust, dirt and snow on the greenhouse film in time can increase the light and raise the temperature of the greenhouse.

4. Covered with plastic film or small arch shed. The high ridge cultivation in the greenhouse can cover the high ridge with a layer of plastic film, which can generally increase the ground temperature by 2 ℃ to 3 ℃, while in the flat cultivation, a small arch greenhouse can be set up to increase the ground temperature.

5. Dig cold prevention ditch. Digging trenches on the south side of the outside of the greenhouse and filling in thermal insulation materials such as horse dung, weeds and straw can prevent the ground temperature from dissipating outward and increase the ground temperature in the south of the greenhouse.

6. Double film covering. Another layer of film is built under the non-dripping film, because there is air between the two layers, the temperature in the shed can be significantly increased.

7. Keep the pool warm. Dig a storage pool every few meters in the middle of the greenhouse, cover the bottom with plastic film, then fill it with water, and then cover the upper part of the pool with a transparent film (to prevent the moisture in the pool from evaporating and increasing the air humidity in the greenhouse). Because the specific heat of water is large, it can absorb heat at noon (at high temperature) and release heat at night.

8. Timely disclosure. When the temperature conditions permit, uncover the late cover as early as possible to promote the photosynthesis of flowers. In the deep winter, when the sun shines all over the shed in the morning on a sunny day, the temperature in the shed is generally not lower than 18 ℃. When the light is weak in cloudy or cloudy days, the grass should be opened in time so that the scattered light can enter, on the one hand, it can increase the temperature, on the other hand, because there is more blue-purple light in the scattered light, it is beneficial to photosynthesis. Do not uncover the grass for a long time, resulting in cold inside the shed and a sharp drop in temperature.

9. Apply more fertilizer. In the shed, horse dung, broken grass and other brewed heat were applied to raise the ground temperature. The decomposition of organic fertilizer can release heat, and the appropriate application of organic fertilizer and phosphorus and potassium fertilizer can not only improve soil aggregate structure, increase soil temperature, provide nutrients for flowers, but also enhance the frost resistance of flowers.

10. Hang a reflective screen. Hanging the polyester aluminized film on the north side of the greenhouse can increase the light in the greenhouse and increase the greenhouse temperature by 2 ℃ to 3 ℃.

11. Heating up. In case of extremely cold weather, you can add a stove or turn on the heating in the shed, but when using the stove to heat up, you should pay attention to prevent the poisoning of flower gas, install chimneys to output gas outside the shed, and be careful not to ignite firewood and grass in the shed to increase the temperature. because the smoke from burning firewood and grass is very harmful to flowers.

12. Scatter grass and wood ash. The plant ash is grayish black and has strong heat absorbing capacity. after it is evenly scattered on the ground of the greenhouse, the ground temperature can be increased by 1 ℃ to 2 ℃.

13. Spray antifreeze. Before cooling, spraying the stems and leaves of the plant with 400-700 times liquid of antifreeze can protect against cold and cold.

Wind damage of flowers in greenhouse

The winter wind is strong in the northern region, and the pressing line of the plastic film in the flower greenhouse can not stand the strong wind, so that the plastic film is blown over or damaged, and the flowers are destroyed at once. The main reasons are: when the wind blows, the shed film and the support friction, such as the support is not smooth, easy to cause a hole, if not repaired in time, the hole becomes bigger and bigger; the vent is too late to close, the strong wind blows into the shed, bulging the greenhouse film, causing damage to the film; the film is not stretched tightly, the film pressing line is flexible or not enough, it is easy to cause a big break, the ground anchor line is buried shallow, and the whole film is easily blown away by the wind. The film with old aging and more cracks is more prone to wind damage; the quality of the film and support is poor and can not withstand the attack of strong wind; improper management, did not pay attention to weather changes, did not take timely measures to protect.

The main measures to prevent wind damage are as follows:

1. Set up wind barriers. 1 to 2 meters away from the shed, corn straw and sorghum straw are used as wind barriers. When building a shed in the open, there should be a windbreak belt around it.

2. Building sheds with specifications. Strictly abide by the requirements of the shed when building the shed. Greenhouse wall, rear roof should be plastered and sealed, film and rear roof lap should be tight, conditional buffer room can be set up.

3. Reinforce the laminating line. Press the film with a special film thread. Change the conventional 100 cm 1 pressing line into 50 cm 1 pressing line, use 1 iron wire as the pressing line every 300 cm, and tighten it with a tensioner.

4. Fix the plastic film. Use common ground anchors. The method is to bury a brick with twisted wire every 2 meters, with a depth of about 50 centimeters. The end of the wire was twisted into a circle and exposed to the surface. After burying, each anchor is strung together and tightened with a No. 12 wire, and each pressing wire can be screwed to this common wire.

5. The single film is covered as a whole. Film selection is the key, we should choose non-obsolete, no holes in the greenhouse film, with high-quality new film, such as the new generation of anti-fog polyethylene drip-free greenhouse film. According to the shed body to select the corresponding specification width of the single film, the single film covers the ground as a whole, no seam is left, and the periphery is compacted and flattened.

6. Cover grass and strengthen management. After the film should be carefully managed, the film should be pressed once every 3 to 5 days, and the holes should be glued and mended in time. In order to solve the contradiction between air temperature regulation and blowing film, a grass pressing film can be placed at intervals of 3 to 5 meters. When the wind blows in the evening, the grass should be covered one by one in accordance with the direction of the wind. The lower ends of the grass should be covered with grass and pressed with stones. If it is windy at night, you should pay attention to repairing the broken membrane in time.

7. Add a "belt". The covering method of 2 to 3 greenhouse films is adopted, and the edge of the film at the suture of the greenhouse film must each add a strong strap as a "belt". The specific method is to clip the pressing line or nylon rope used for reinforcement in the film, iron the shed film with an electric iron or iron, fix the rope at both ends after the film, and fix the length of the shed body at intervals of 5 to 10 meters.

8. Master the method of covering membrane. The conventional method of covering the film is to press the upper side and the lower side. In this method, due to the gap at the joint and the large wind resistance, the greenhouse film is easy to be blown open by the wind. if it is changed to the lower side and the upper side, the wind is not easy to blow the film open, even if Rain Water flows in the shed.

9. Transformation of shed structure. The distance between the pull rod or tie rod of the arch shed or greenhouse skeleton and the greenhouse film is 10 to 15 cm. If the interval is too small, it is easy to wear out the greenhouse film, and the other is that it is not easy to compact the greenhouse film with support, so the support is required to be firm and the place in contact with the film should be smooth.

10. Adhere to multi-layer coverage. Adding double-layer grass, adding grass quilt or quilt, or using double-layer film, or adding a small shed in the shed can improve the windproof effect.