The Dangers of Tree Topping or Dehorning

In traveling throughout the state of Ohio each year, I see many different and exciting things being done with trees and plants, including new cultivars chosen and properly placed on sites. Unfortunately, I’ve seen growing evidence of a dangerous practice, too. Specifically, tree topping or tree dehorning has become quite widespread, and that’s a shame. Because this has become such a prevalent method of controlling a tree’s growth, by the arboriculturally less well educated, I’d like to touch on what it is, why it is harmful, and what you can do instead to insure the health, beauty and safety of your trees.

Tree dehorning, or also called tree topping is the practice of cutting the branches of a tree away from the upper portion of the tree until all that is left is trunk tissue and branch stubs. This really amounts to tree slaughter. It causes stress that can shorten the tree’s life by 25 to 50 years or even kill it within 2 or 3 years and also produces an unattractive and unnatural part of your landscape. The only situation I can think of where tree dehorning is justifiable is in the event a tree interferes with our public utilities. In that case, I’d rather see the tree chopped up, than chopped down. Even then there are more preferred procedures for reducing a tree’s height.

To take off the natural top and/or sides of a tree significantly removes the tree’s ability to manufacture its own food; and this will, in turn, cause root loss. In addition, tree toping causes certain other physical and internal problems.

A tree that has been topped will usually produce water sprouts that will grow in large numbers from the branch stubs. This adds weight and density to the tree and may cause it to become a wind block or an ice trap and place it in danger of being toppled or split. As a result, the tree is physically not as safe as it originally was. Ironically, many people choose to top their trees because they believe a shorter tree is a safer tree. This is definitely not so. Also, the tightly placed packed leaves and water sprouts can make the tree more susceptible to leaf disease.

Because topping robs a tree of its crucial barrier tissue, water can seep down into the open wound of the tree where it will eventually cause the internal tissue to rot. One particularly disgusting by-product of this is “slime flux”; a combination of water and bacteria and/or fungi that escape from unnatural openings in the tree, especially the branch crotches. This substance kills the bark on its way down the trunk, and anything else it comes into contact with. This can occur in trees that have not been unnecessarily cut, but it is most definitely encouraged by dehorning or topping.

Fortunately, wise pruning can make dehorning or topping a thing of the past. Usually, a good pruning job is one you can’t see from 2 or 3 blocks away. That’s because as few as one or two branches may be all your tree needs to have removed at any one time. As always, first take out the dead, badly crossed, or diseased branches and work to open the center of the tree to better light and airflow. This may also require the removal of some live, but poorly spaced branches. The end product is a safer and more beautiful tree, and not just stubs left where a beautiful tree once prospered.

If you have someone else prune your trees, and this is recommended, check to see that they are properly insured, have the necessary workmen’s compensation coverage and employ I.S.A. certified arborists and have a good reputation for the preservation of tree health. In short, find someone who understands the damages caused by topping or dehorning and wouldn’t dream of doing it to one of your trees. Anything else just isn’t worth it.