Pruning is one of the most common tree maintenance actions. Landscape trees require a proper level of care which should include pruning to maintain their safety and aesthetics. Pruning should be done with an understanding of how the tree will respond to each cut. Improper pruning can cause damage that will last for the life of the tree or it could even shorten the tree’s life.
Reasons for Pruning
Because each cut has the potential to change the growth of the tree, no branch should be removed without a reason. Common reasons for pruning are:
- To remove dead branches
- To remove crowded or rubbing limbs
- To eliminate hazards
Trees may also be pruned to increase light and air penetration to the inside of the tree’s crown or to the landscape below. In most cases, trees are pruned as a corrective or preventive measure.
Routine thinning does not necessarily improve the health of a tree. Trees produce a dense crown of leaves to manufacture the sugar used as energy for growth and development. Removal of foliage through pruning can reduce growth and stored energy reserves. Heavy pruning can cause a significant health stress for the tree.
In-town environments do not imitate normal forest conditions. Safety is a main concern. In addition, we want trees to balance and compliment other landscape plantings and lawns. Correct and appropriate pruning, with an understanding of tree biology, will protect tree health and tree structure while enhancing the aesthetic and beauty of our landscapes.
When to Prune
Tree and shrub pruning to remove weak, diseased, or dead limbs can be accomplished any time during the year with little effect on the tree. As a rule, growth is maximized and wound closure is fastest if pruning takes place before the spring growth flush. Some trees, such as maples and birches, tend to “bleed” if pruned early in the spring. It may be unsightly, but it is of little consequence to the tree.
Tree pruning just after the spring growth flush should be avoided. At that time, trees have just expended a great deal of energy to produce foliage and early shoot growth. Removal of a large percentage of foliage at that time could harm the tree.