Shade trees require pruning for the same reasons as other landscape plants: Prune to conform to a specified size and shape, prune out excess branches to prevent rubbing together, removal of broken or damaged branches, double leaders or narrow v-shaped crotches. Most homeowners should limit their tree pruning to small branches, which can be reached from the ground. The pruning of large branches and work off the ground should involve professional tree experts with proper equipment.
Many people are under the impression that large shade trees need pruning just because they're getting too big and pretty or because it's a certain season. We witness this all across the state. Before having a tree trimmed, know why and how it should be done.
Many pruning jobs could be avoided by knowing the growth habit of a specific tree. Find out how fast and how large a tree normally grows. With this information you can avoid many maintenance requirements. Logic and reason also apply. For example, don't plant a white oak directly beneath utility lines. As the tree grows and interferes with the lines, the tree will be pruned. This completely destroys the natural character of the tree and often leads to its early decline. The same is true when choosing a tree for a planter or other limited space. Consider small or intermediate size trees such as Crape Myrtle, Foster Holly, Redbud or Japanese Maple.
How to Prune - The basic principles of pruning apply to trees. Cut back to a lateral side branch or bud, or back to live, healthy wood. Make the cut at a slant next to a bud that can produce new growth. "Thinning out" is a term used to describe removing an entire branch at its point of origin. This procedure results in a more open tree and is the least conspicuous of pruning habits. This also conforms to the normal branching habit of the tree. Remove "narrow" crotched limbs as they are the weaker branches of a tree.
"Flush cut and paint" have been the standard recommendation for pruning trees for more than a century. However, research by the United States Forest Service has shown that this practice may work against nature's design and the trees' best interest.
At the base of every branch is a collar that contains a chemical zone, which inhibits the spread of decay in the trunk. When decay develops in a branch, it moves down the branch until it reaches the protective chemical zone. Once there, it stops and a callus forms after the branch falls off.
If the collar of the branch is removed during pruning, the chances of the trunk becoming infected by decay and canker-causing microorganisms are greatly increased. When pruning you should not make cuts flush with the trunk, but make them just outside the branch collar. The branch collar is the swollen area at the base of the branch that sometimes has a bark ridge.
