Young trees are small, and the pruning amount should be light; Old trees are the opposite. Although young trees grow vigorously, pruning has an important influence on crown formation. Old trees have many dead branches and weak branches, so they should be pruned again or even updated.

2. Different tree species have different pruning degrees.

If you do the same regular head shaping, different tree species will be different. For example, for boxwood with dense branches and leaves, the pruning amount will be lighter, while for Acer truncatum, the pruning amount will be heavier. Deciduous trees are generally more resistant to pruning than evergreen trees, especially trees such as Platanus acerifolia and Liriodendron chinense are more resistant to heavy pruning than camphor trees and Magnolia grandiflora. Shrubs are usually more resistant to pruning than trees.

3. Pruning in dormancy and growth period is also different.

Pruning in dormancy period is heavier than pruning in growth period. Because the pruning in the growth period is mainly based on bud wiping, core removal, twisting, flower thinning and bud thinning, the pruning amount is light. Thinning and short cutting are combined in dormancy period, so the cutting amount is large. Therefore, in order to reduce the nutrient consumption of trees, especially to avoid serious injuries, pruning should be advocated in the growing period, or pruning should be given priority to in summer, supplemented by pruning in winter.

In addition, all tree species with serious bleeding and weak cold tolerance, such as grapes, walnuts, Acer negundo, Pterocarya stenoptera and Sizhaohua, should be pruned more than 20 days before germination in early spring.