You can top off a refreshing beverage and you can top off the gas tank in your car, but when it comes to trimming your trees, topping is something that most experts agree should be avoided. The following explains why topping is one of the least desirable options for tree trimming and what methods should be used instead.
Topping Can Stimulate Too Much Growth
The topping process often strips the tree of its leaf-bearing crowns, which also strips the tree of its normal food source. Faced with the temporary loss of its main food source, the tree uses a unique survival technique to replenish and restore its means of food production.
Numerous basal shoots quickly sprout from latent buds located beneath each cut, allowing the tree to put out new leaves as shortly as possible. These new shoots allow the tree to grow back to its original size within several years, but the new growth is much denser than before. This often makes the tree look even thicker and unmanageable than it was before it was topped.
Topping was once used as a way to deliberately stimulate new growth. However, the new growth often comes with consequences of its own.
Topping Can Leave Trees Weaker Than Before
The very act of topping a tree can severely weaken it in a variety of ways. For instance, the wood within the cut branch may begin to decay due to a lack of food, weakening the basic structure of the tree itself. A freshly topped tree may also be more vulnerable to damage caused by high winds during periods of severe weather.
The basal shoots that grow from the parent branches also lack the structural integrity of their predecessors, leaving them more vulnerable to breakage. Since there are often so many new shoots growing from a parent branch, there's always a chance that these branches can suddenly break off in bunches, which could be dangerous for any passerby who happen to be underneath the tree when it happens.
A Topped Tree is An Open Invitation to Insects and Pathogens
Topped trees are also more susceptible to attacks by various insects and pathogens. The cuts can leave behind open wounds that allow insects such as tent caterpillars, elm bark beetles and gypsy moths to infest and potentially destroy vulnerable trees.
Although most trees are capable of repairing themselves with time and care, cuts made on outlying branches may leave wounds that prove impossible to close. The new growths that result from tree topping are also vulnerable to insects and pathogens.
Pruning Alternatives to Consider
Instead of resorting to tree topping, there are several other tree pruning methods that are not only healthier for the tree, but also more aesthetically pleasing:
- Windowing – This method involves carefully pruning main branches to create a "window" through the tree canopy. When done properly, windowing creates a pleasing appearance while keeping the tree healthy.
- Crown raising – This method involves pruning some of the lower branches on the tree to create a clear view, effectively "raising" the profile of the tree canopy.
- Drop-crotching – This method shrinks the overall canopy profile by pruning large branches back to the nearest lateral growth.
When Should Topping Be Used
Although most reputable tree trimming companies try to avoid topping whenever possible, it may be the only course of action available in some rare cases. For instance, some arborists may resort to topping a tree if other methods of pruning deliver poor results. Topping is also used to spur fruit production in most fruit trees. However, unless you're expecting a bumper crop of apples or peaches, it's usually best to avoid topping altogether. For more trimming tips, contact a company like Smitty's Tree Service Inc.