1, usually in winter, when plants enter dormancy or semi-dormancy, this time is just right, and plants will not be tossed too much.

2, usually pruning, generally cut off yellow or sick, and some leaves are torn. It is particularly important to note that if the yellow leaves are caused by air drying and the area is not large, you can only cut the tip of the leaf. During dormancy, cut off those thin and dense branches, which will hinder its growth too much.