General winter planting leafy vegetables in the shade net directly cover surface (surface coverage), in case of low temperature damage, because of its light weight, only 45 grams per square metre, the tree has grown into a high leaf also
Will not overwhelm, bend, reduce commodity. Because it has certain air permeability, the leaf surface is still dry after being covered, which reduces the occurrence of disease. It also has a certain light transmittance, cover will not "cover yellow, cover rotten."". Henan Agricultural University in 1997 in Linying County of DragonTown vegetable park has been basically established in winter Plastic Greenhouse Celery, inside of the surface coverage for cold protection, the results showed that the surface coverage in the shade outside -6 deg.c, celery leaves not found a lot of ice; and the single shed controls, especially in the upper leaves was frozen hard by, the determination of coverage than those who control high temperature of 1.5 DEG C.