Topping: Just say no!

City tree topped to keep branches away from power lines.

Every few years, there is a rash of tree topping in our community because disreputable tree companies have convinced homeowners that topping their trees will improve the trees? safety. In fact, the opposite is true. Topped trees have much more decay in them, have weakly attached branches and will drop hundreds of branches over the next few years. Most arborists know that topping is one of the worst things you can do for the health of your tree. As more is learned about the long-term effects of topping, the more senseless this practice becomes.

?Topping? is reducing the height of a tree by cutting off the tops of the branches. Stubs are three inches or more in diameter. It?s like giving a tree a butch haircut. Other names for topping are stubbing, heading, tipping, dehorning, lopping and rounding-over. Starvation: Good pruning practices rarely remove more than of the living crown so that the tree?s crown-to-root ratio is not upset. Topping, on the other hand, removes so much of the leafy crown that it upsets the balance between roots and crown and temporarily cuts off the tree?s food making ability. Topped trees commonly loose vigor and may even starve to death within a year or two.

Insects and diseases: For the first growing season after topping, the wounds on the stubs are very attractive to insects and disease-causing fungi. Thereafter, insects may be attracted to the tree if the tree still low vigor from the effects of topping.

Rapid new growth: People who top their tree intend to control the height and spread of their tree. Unfortunately, topping has just the opposite effect. The new sprouts are far more numerous than normal and they elongate so rapidly that the tree returns to its original height in a very short time and it has a much denser crown.

Weak branches: After being topped, a veritable broom of new sprouts will grow on the end of each branch stub. As they increase in size and compete for dominance, smaller branches on each stub are shed for a number of years. Dozens to hundreds of branches will need to be picked up each year until one or two sprouts become dominant on each stub.

Increased decay: Topping trees vastly increases the amount of decay in all the cut branches and down the main stem. Each and every time a branch is topped, a wound is created which is infected by decay-causing fungi. In as little as five years, the stub wood is decayed and the stub has trouble supporting all the new sprouts on its tip.

Disfigured: A topped tree is a disfigured tree. Its natural shape and form are gone. Even with its new sprouts, a topped tree never regains the grace and character of its species.

City tree topped to keep branches away from power lines.

Cost: To a worker with a saw, topping is much easier than applying the skill and judgment needed for good pruning. So topping may cost less in the short run. However, the true costs of topping are hidden. These include: reduced property value, expense of removal and replacement if the tree dies, the risk of liability from fallen branches and increased future maintenance.

From a safety standpoint, topped trees and their new sprouts will become a hazard in a few short years. Decay will spread into the main stem and the cores of all the branch stubs will be rotten. Each year, dozens to hundreds of sprouts/ branches will fall to the ground.

There are times when the size and shape of a tree need to be controlled. With care and skill, this can be accomplished without topping. Responsible pruning even contributes to the health and safety of the tree. As alternatives to topping, some general principles are:

  1. Plant the right tree in the right place. Plant a tree that will fit into the landscape when it reaches maturity.
  2. Begin proper pruning early in the life of a tree.
  3. Avoid the use of nitrogen fertilizer because this allows the tree to grow taller and faster.
  4. Prune properly and regularly. A light pruning of small branches every five years will keep your tree in good condition and prevent decay.

Proper pruning will also have less drastic effects on both the landscape and your financial assets compared with neglecting older trees or resorting to topping.

Adapted from: James Fazio (Editor), ?Don?t top trees?, Tree City USA Bulletin No. 8, National Arbor Day Foundation.