A few years ago, a guy in a pickup truck filled with ladders and chainsaws came through my neighborhood looking for tree-pruning work. Unfortunately, several of my neighbors hired him. Four homes in a row that each had stately 50-year-old maples in their backyards now have big, fat tree trunks with a bunch of spindly waterspouts waving from the tops.
Lesson: Tree topping is the most harmful thing you can do to a tree.
Tree topping is cutting off the top of a tree, usually to shorten it or reduce its spread.
Topping can remove from 50 to 100 percent of the leaf-bearing tree crown. Trees need their leaves to produce food and severe topping can temporarily starve a tree. The tree immediately goes into survival mode and activates latent buds just below the cuts, forcing rapid growth of multiple shoots below each cut, as it tries to put out a new crop of leaves as fast as possible.
Shoots can grow as much as 20 feet a year, defeating the goal of shortening the tree. If the tree has been stressed for any other reason (such as last year's drought) and doesn't have the stored energy reserves to put out that new growth, it will be severely weakened and may die.
If the tree does survive, the new sprouts that grow below the cuts will eventually get big and take on considerable weight. They've developed in the outermost layers of old branches rather than deep inside a "socket" of overlapping wood tissues and are susceptible to breakage, even years later when they get really heavy. This is ironic, since one of the reasons people have their trees topped is to make them safer.
Tree topping also invites decay. When branches are properly pruned, just beyond the branch collar at a branch's point of attachment, the tree produces chemicals to seal and protect the cut. But a tree is not biologically equipped to do that anywhere else in its structure, so large upper cuts or stub cuts are wide open to decay, insects and disease.
A large shade tree's lower leaves and branches are protected from harsh sun by the upper branches. Cutting off those upper branches can cause the newly exposed lower leaves and bark to be scalded by the sun, causing the tree to die.
And topped trees are really ugly. The natural form of the tree is destroyed and its grace and beauty are gone forever. In winter, the tree is especially unsightly as large branches end abruptly in a spray of sprouts. In summer, dense balls of foliage are unattractive and unnatural.
There are ways to properly reduce the size of a tree if it must be done. A certified arborist is the person who can help. To find one, visit the Wisconsin Arborist Association website: www.waa-isa.org/ arborists/search.asp. Whether you decide to hire a certified arborist or someone else, make sure you ask for proof of insurance or you could have worse trouble on your hands than just an ugly tree.