There are a few primary reasons to prune trees. The USDA lists three: safety, health, and aesthetics. I prune for all of these reasons.
Safety pruning covers many areas. There were trees in our yard that interfered with mowing the lawn. Invariably I would hit my head or impale myself while riding the mower. I took off many of those branches. That's pruning for safety. If you keep having to duck under a branch on a path you might consider removing it. I cut off pine branches that hindered the view out of the windshield as we drove from our driveway onto the road. If weak or over-sized branches begin to interfere with power lines or overhang your house, removing them is a good idea.
|This branch is too low.|
One of the main reasons I prune is for aesthetic value. Trees are a major component in any garden's appeal; a good-looking tree can benefit the garden and landscape. The aesthetics are a personal choice. I like a balanced look in trees with branches looking natural, yet orderly. I'll prune branches that are too close together or that aren't symmetrical to neighboring ones. It brings out the artist in me as I sculpt the landscape through selective removal of limbs.
|This small branch grew up, then crossed over and down. It was unsightly.|
The health of the tree is the third primary reason. Diseased or infested limbs should always be removed. If snow or wind breaks a branch, pruning the affected limb correctly can improve healing. I look for crowded areas of growth and prune to increase airflow and light throughout the tree; this can lessen pest problems. I also look for branches that are interfering with others and prune to allow proper growth.
|A dead branch that needed to go.|
Pruning is more than just cutting off a branch. There's a right way to do it; if done correctly, the tree will naturally cover up the wound and heal well. If the pruning cut is bad, the tree may be more susceptible to insect damage, disease, or rot.
For thinning out branches, cutting off twigs from a limb is as simple as clipping or sawing it cleanly and evenly. You want to avoid leaving nubs that stick out; remove as much of the twig or branch as you can.
For removal cuts next to the trunk you'll want to determine the proper cutting angle. Look for the branch collar and branch bark ridge. These are technical names for the bulges at the base of branches. The collar is the thicker band of growth at the bottom of the branch where it grows from the trunk; the bark ridge is the crumbled area at the top where the bark of the trunk meets the bark of the branch. If a branch is cut off just outside the branch collar, about 1/4 inch, tree tissue will grow over the cut like a donut and protect it from decay. Ideally you'll want to prune off branches before they reach two inches thick. The cut will rarely be flush with the trunk and usually angles out slightly from the top to the bottom.
|A cut covered with dried sap and beginning to heal|
For particularly large limbs, make an initial shallow cut into the bottom of the branch about six inches or so outside the branch collar; this is to reduce the chance that the bark will strip off in the next step. Then cut completely through the branch a few inches beyond that. The third and final cut should be just outside the branch collar. Because you've already removed most of the branch, the weight and size of the final piece you're removing is very manageable.
|Branches awaiting the final cut.|
I don't recommend putting a dressing on the cut. It used to be thought that applying something like a poultice to a tree wound would promote healing and protect it from harmful organisms. It's found that the opposite is often true.
|Some of my pruning tools.|
With practice, pruning is quick, easy, and benefits the tree and the aesthetics of the garden. Pruning fruit trees can be more complex and I'll cover that in another article. There are other issues when pruning bushes and I'll cover that later too. For now, take a good, hard look at your trees. Look for damaged branches, unsightly branches, overcrowded branches, and annoying branches. Remove them and have fun with it.