Graph showing the shape of pruning on a large branch. We will cut it in three stages to avoid injuring the trunk.
Pruning is the process of trimming a tree or shrub. Done carefully and correctly, pruning can increase fruit yield; thus, it is a common agricultural practice. In forestry production it is used to obtain trusses that are straight and with less branches, therefore of higher quality. In urban woodland its usefulness is, on the one hand, to prevent the risk of falling branches, and on the other hand to control the size of trees whose location does not allow their full development.
Gardening is often used the pruning to get artificial forms in the trees or shrubs. Well executed and repeated with the appropriate periodicity can increase the ornamental value of the same. However, it is often improperly practiced (mutilations such as topping), causing wood decay that shorten tree life and increase the risk of branch failure. On the other hand, too radical cutting of the tree often compromises its survival.
Each tree requires a different type of pruning. As a general rule the most important prunings are:
- Cup pruning, pruning or peeling. It is done in the first year, it consists of pruning the main branch of the cup to favor the branch.
- Training pruning. It is done after several years, to give a suitable shape to the tree.
- Slimming pruning. It is about cutting whole branches, sometimes done at the same time as the forming. It helps the formation of the cup.
- Winter pruning. It is carried out in winter on trees of slow or little vigorous growth. It slows the formation of flowers.
- Summer pruning or green pruning. Its purpose is to regulate growth.
The process by which a tree protects itself from the entry of parasitic organisms into pruning cuts was described in 1977 by Alex Shigo, calling it the CODIT (Compartmentalization Of Decay In Trees) model.
In some countries, such as Mexico, specifically in the Federal District, there is environmental legislation that protects urban trees and refers to local regulations that regulate pruning activity such as the Environmental Regulation for the Federal District NADF-001-RNAT-2006, that although it is subject to revision and modification, is a good attempt in the protection of these individuals, and especially the prevention of risks to the inhabitants of this city.
When the pruning process is carried out in large trees are before a specific pruning technique, pruning height. To carry it out, it is necessary to have elevating elements to reach the branches of greater height, generally to several meters, or to make use of climbing techniques that allow the pruner to climb and prune the branches.