There are many reasons to prune a tree. It is best to remove diseased branches to stop the growth of the disease and to remove the not-too-attractive parts of the tree. Or say a damaging storm has left branches partly broken off and dangling; the tree will be much happier with these branches taken off. Perhaps a tree needs the crown trimmed permitting better air circulation so that healthy new growth will start to appear. A tree also needs pruning when lower branches are obstructing the way, a view or the growth of lower shrubs. Maybe you would like to train the tree to grow in a certain direction for design purposes, then pruning could be a consideration. And there is always the reason of reducing the tree's height because it has just grown too tall.

It is best to prune during the dormant season in late fall or winter. However, dead branches can and should be removed at any time. Pruning during the dormant period minimizes sap loss and subsequently, any stress to the tree. Because fungus infection and/or insect infestation are also in dormancy during this time, pruning a tree then minimizes the risk of their damage invading the tree. Also, in the case of deciduous trees, pruning when the leaves are off will allow you to design your cutting with the overall structural shape of the tree.

Once you decide which trees need pruning, next determine whether or not you can do it yourself or need to hire the experts. If the tree is tall and involves large branches especially near the top, then there should be no question. Never compromise personal safety in pruning a tree. Large tree pruning may require climbing, heavy saws, or even chain saws. A trained, knowledgeable and experienced tree service professional knows how to handle these jobs the best.

Among the pruning jobs that you can do yourself, remember in all cases, to protect the stem or trunk wood of the tree while pruning off the unwanted branches. Tree branches grow from stems at nodes and pruning always takes place on the branch side of a stem-branch node. Branches and stems are separated by a lip of tissue called a stem collar. The stem collar grows out from the stem at the base of the branch. All pruning cuts should be made on the branch side of this stem collar. This will help protect the stem and any other branches growing from it making the healing after the prune more effective. Do not paint the cuts with compounds that prevent air from accessing where the pruning took place, thereby slowing the healing process.

To prevent tearing of the bark and stem wood, particularly in the case of larger branches, use the following procedure: First, make a small wedge shaped cut on the underside of the branch just on the branch side of the stem collar to let the break happen at that point and prevent a tear from running along the bark and stem tissue. Then, starting at the top of the branch, farther along the branch, cut all the way through the branch leaving a stub end. Finally, make a third cut parallel to and only on the branch side of the stem collar to reduce the length of the stub as much as possible.

Newly-planted trees should not be pruned until they feel settled in their new growing spot. Prune only if there happens to be any damaged or broken branches. Do not prune the top of the tree as this could alter the structure of the tree excessively, according to which tree species it is, and may hamper necessary carbohydrate production.