1. Increase the permeability of the shed membrane
It is recommended to use a high-transparency, non-drip film, and to clean the dust and snow on the shed film in time, which can enhance the light and increase the temperature of the shed.

2. Improve the thermal insulation of grass curtains

The grass curtain covering the greenhouse should be firm. In order to improve the thermal insulation performance, in the deep winter season, in order to prevent rain and snow from wetting the grass curtain, the grass curtain can be covered with a layer of ordinary agricultural film or old film.　

3. Increase the thermal insulation of the rear wall

When building the back wall, a layer of brick can be affixed to the soil wall, or a hollow thermal insulation wall can be built, and the wall is filled with straw or polystyrene foam board. The cold area can be directly built into a fire wall, which is convenient for raising the temperature.　

4. Digging the cold-proof ditch outside the shed

Dig a cold-proof ditch with a depth of 40-60 cm wide and 40-50 cm outside the greenhouse, fill it with insulation materials such as sawdust, weeds, horse dung, and straw, and cover the trench with soil to achieve the effect of insulation. When the cold current is approaching, adding grass curtains or corn stalks and other packaging machinery agricultural films around the shed at night can increase the shed temperature by 2-3 degrees Celsius.　

5. Digging back the ditch in the shed

Dig the ditch at a depth of 45 cm and a width of 50 cm at a depth of 30 cm to 35 cm along the planting line. The bottom of the ditch is covered with rice husks or wheat bran of about 5 cm. Put a wooden pile every 50 cm from the side wall of the ditch 5 cm and fix it. The wooden pile and the side wall are stuffed with corn stalks. The top of the ditch is covered with 60-70 cm long corn stalks with a diameter of 10 cm. The earth is covered on the ditch. Except for leaving the working path, the rest of the ground is covered with mulch. The entire greenhouse forms an "S" shaped ditch that is connected end to end. Set an opening at a slightly higher place, open or close in time to control the ground temperature.

6. Establish temporary heating measures

2-3 temporary heaters with a power of 1600-2500W can be temporarily set in the shed. The direction of the outlet of the heater should not directly face the plant.　　

7. Hang the reflective curtain in the greenhouse

Hang the plastic film or tin foil coated with metal layer on the back wall of the shed. It is recommended to hang 1 meter every 2-3 meters, so as to reduce the absorption of heat energy by the wall and increase the temperature in the shed by 2-3 degrees Celsius.