2. Culturing the soil to prevent cold: Culturing the mound within 30cm of the seedling base to prevent frostbite of the root neck. When the temperature rises and stabilizes in the next spring, take it out and flatten the tree.
3. Whitening and cold protection: Whitening the young trees can alleviate the temperature difference between the yin and yang sides of the trunk, which has a good cold protection effect and can be applied before the soil freezes. The formula of whitening agent for reference is: salt 0.5 kg, quicklime 6 kg, clear water 15 kg, and then add a proper amount of binder and stone sulfur mixture residue and spread all the young branches.
4, polyvinyl alcohol coating: evenly coating the trunk of the seedling with boiled polyvinyl alcohol. The boiling method of polyvinyl alcohol is that the ratio of polyvinyl alcohol to water is "1: 15-20". First, heat the water to about 50℃, then add polyvinyl alcohol (it can't be added after the water is boiled, otherwise the polyvinyl alcohol can't be completely dissolved, and the solution is uneven), stir it until it boils, and then simmer for 20-30 minutes. Wait until the temperature drops and it's not hot.
5. Wrapping for cold protection: wrap the trunk with straw or plastic film to reduce the water loss of walnut branches and avoid pulling, and untie it before germination in the next spring.