If you intend to trim your trees yourself, there are a few things you should know before you begin.

First, you should have a good reason for trimming a healthy tree.

Some of the reasons for trimming a tree include the following:

• The tree has a few diseased or damaged branches.
• The tree’s crown has become too thick to allow air circulation.
• The tree is too tall for your liking, or it is interfering with something above it.
• The tree’s lower branches hinder your vision.
• The tree needs to be shaped for aesthetic purposes.

If any of these reasons sound familiar to you, then you have a good reason for trimming. Otherwise, you shouldn’t remove branches. Just let the tree grow naturally until there is a problem.

As with any other household job, know your limits. If you have very large branches to remove, leave the job to an expert. Otherwise, proceed with caution!

Next, learn the proper steps to trimming trees.

Learn what the branch collar looks like. This is the ring of swollen-looking growth at the base of each branch. Examine the branches you plan to remove so that you know exactly where the branch collar is.

When you begin trimming the branches away, make your cut close to the branch collar on the branch side, not the trunk side. Cutting too close to the tree’s trunk will leave an unsightly scar that may never heal completely, or it may overcompensate during healing, leaving behind a noticeable bulge in the tree trunk.

It’s a good idea to remove as little as possible when you are trimming a tree. Just like getting a haircut, you can always take off a little more if you decide that’s best, but you can’t put it back on once it’s gone.

If you are trimming the tree for thinning purposes, the crown should be two-thirds of the tree’s total height, and branches should be evenly spaced.

Then, you should know the best time of year to trim trees.

It’s always best to trim trees during their dormant season, which, for most, is late fall or winter. Less sap will be lost during this time, and the risk of infection from fungus or insects is much lower. Finally, pruning deciduous trees when they do not have leaves will help you picture which branches should stay and which should remain for the sake of the tree’s appearance.

The only exception to winter pruning is to prune in the summer if you want to keep the tree from getting very large. If you trim it when it has finished its seasonal growth, it will not have as many leaves and, therefore, less opportunity for future growth.

Dead or damaged branches can be removed at any time, however. After a storm, for example, you may see that a broken limb is pushing on others, posing a risk to other branches or to people or property. This limb can be safely removed no matter what time of year it is.