Tree topping is a common but detrimental practice that damages a tree's health and value.
What does "tree topping" mean?
Very simply put, tree topping is the indiscriminate cutting back of tree branches to stubs.
Without its crown, a tree cannot protect its sensitive bark from damaging sun and heat. The result will be split bark and dead branches. The loss of so much of its protective crown starves the tree, which weakens the roots. Tree topping weakens trees, leaving them vulnerable to insects and disease, which shortens their lifespan.
Topped trees appear disfigured and mutilated, but the freshly sawed tree is just the beginning of the neighborhood eyesore. The worst is yet to come as the tree regrows a witch's broom of ugly, straight suckers and sprouts.
A tree's 80-year accomplishment of beauty and natural taper can be destroyed in a couple of hours. Once topped, the tree can never return to its natural shape, and this may actually cost you money. A tree, like any landscape component, adds to the value of your property. Home appraisers can subtract hundreds of dollars from the value of a tree when it's been topped.
Topped trees also eventually increase liability because of safety issues, which is ironic because the most common reason given for topping is to reduce tree size. People fear that tall trees could pose a hazard. The reality is, once a tree has been topped, it's likely to become more hazardous as decay and disease set in.
A topped tree must be done and redone every few years and eventually removed when it dies. A properly pruned tree, on the other hand, stays "done" longer because the work doesn't stimulate an upsurge of regrowth. Proper pruning actually improves the health and beauty of a tree, saving you money in the long run.
The best time to prune most trees, especially deciduous (trees that lose their leaves in the fall), is late in the winter before their leaves form. January is a good month to prune.
The key to good pruning is understanding that branch wood is distinct from trunk wood. Cutting branches flush with the trunk robs the tree of natural chemicals it needs to close the wound, leading to decay. The guiding principle of good pruning is to cut the branch, not the branch collar.
What's a branch collar? Take a close look at the underside of the branch. See the slight swelling on the bottom of the branch, just before it enters the trunk? This area is called the branch collar; take care not to cut into it. Also, use sharp tools and make clean cuts.
By lightly pruning a tree while it's still young, you can take measures to ensure the tree won't become a hazard later. Trees with a main stem or trunk that branches into a narrow fork often form a "V-crotch" with "included" (embedded) bark in it, a structurally weak part of the tree. Remove one of the branches or stems to create a strong control leader. You can do this by retaining the stronger, more vigorous, larger crowned side and removing the less desirable limb.
In older trees, one of your primary pruning objectives is to reduce potential hazards by removing weakly attached limbs and broken branches. Just remember, removing even 25 percent of live foliage from mature trees is too much in many circumstances. Also, refrain from removing any live foliage from a stressed tree; the food produced by their leaves is particularly critical for healthy tissue, roots and replacement branches.
For more information about trees and tree care, see www.treesaregood.com/treecare/treecareinfo.aspx.
Cynthia Orlando is a certified arborist with the Oregon Department of Forestry.