Walnut trees are well protected against cold.

Cold prevention measures can be taken after walnut trees have fallen leaves (usually from mid-November to early December).

First, bury the earth to guard against cold

For the 1-2-year-old young trees which can not survive the winter safely in the open field, the whole tree body should be bent to one side and covered with soil. this method is the most effective and reliable measure to prevent striping.

Second, cultivate soil to guard against cold

Cultivate a mound within 30 cm of the base of the seedling to prevent frostbite on the rhizome and the graft interface. Remove the tree plate after the temperature picks up and stabilizes in the coming spring.

Third, paint white against cold

The white coating of young trees can alleviate the temperature difference between the yin and yang sides of the trunk, and has a better cold-proof effect, so it can be applied before the soil is frozen. The formula of whitening agent is: 0.5 kg of salt, 6 kg of quicklime, 15 kg of water, and then add an appropriate amount of adhesive and the residue of stone-sulfur mixture to cover the branches of young trees.

IV. Polyvinyl alcohol coating drying

Brush the trunk of seedlings evenly with boiled polyvinyl alcohol. The preparation method of polyvinyl alcohol is as follows: the mixture of polyvinyl alcohol and water according to the ratio of 1: 15 / 15 / 20. First boil the water to about 50 ℃, then add polyvinyl alcohol (do not wait for the water to boil before adding, otherwise polyvinyl alcohol can not be completely dissolved, the solution is uneven), add while stirring until boiling, and then simmer with a gentle fire to make it 20ml for 30 minutes. Use when the temperature drops to the point where the hand is not hot.