You have undoubtedly seen a lot of trees, perhaps you have even grown some on your own property. But how much do you know about trees and their pruning needs? There are some aspects of this you need to consider.
First, you have to understand how a tree works, to find out the importance of tree pruning. In essence, the tree is a complex living organism with a self-supporting system. Trees convert carbon from our atmosphere into sugars, which are used to create blocks of cellulose and lignin to sustain themselves. Trees absorb water, along with other essential nutrients through the roots. These nutrients are transported to the leaves via a tubular system of vessels, known as the xylem. Minerals and sugars are then used by the tree to flower and produce fruit.
You may wonder why you need to prune trees. The main purpose of pruning is to improve the structure of the tree. In essence, pruning consists of controlled removal of branches, so there is also the benefit of clearing broken branches. If the tree is planted close to a structure, you may need to prune it just to provide some clearance. You should only prune trees that need it because removing a big branch creates an opportunity for disease entering via the wound or simply weaken the tree through the removal of a large part of leaf material. Removing branches is not a safe process, as it requires special gear and training. In many cases, you need to leave this job to expert arborists, who can easily handle the task.
To prune a tree correctly, you need to understand how branches work. They grow from buds, which in time become twigs. During the process of incremental growth, in which the tree produces a ring of growth, the branches grow as well. The point where the branch attaches itself to the tree is known as the branch bark ridge. To keep the wound of pruning as small as possible, you need the final cut to be no larger than a third of the stem/branch. If you are removing a branch, you must do the final cut from the bark ridge to the collar in such a way as to minimise the final wound. If you remove a large branch, you up the risk of disease. Fungi and bacteria can enter the tree via the wound and cause all sort of trouble.
Pruning should not take place at random periods. Generally, you should do it after the leaves have had a chance to harden, i.e. late spring and early summer. However, there are exceptions to this rule, such as with Walnut, Maples and Birch, all of which bleed sap if pruned in spring. For these trees, you should wait for mid-summer or mid-winter pruning.