Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: THURSDAY, June 1, 1995                   TAG: 9506010046
SECTION: CURRENT                    PAGE: NRV-13   EDITION: NEW RIVER VALLEY  
SOURCE: JOE HUNNINGS
DATELINE:                                 LENGTH: Medium

TOPPING DOESN'T WORK, AND IT OFTEN HURTS THE TREE

Let's look at why you should avoid topping and what are acceptable alternatives.

What is "topping"?

Topping occurs when the vertical stem (leader) and upper primary limbs (scaffold branches) on mature trees are cut back to stubs at uniform height. Topping damages trees in several ways:

Topping reduces food-making capacity. Trees require a large leaf surface area to provide food for maintenance and growth. Topping cuts off a major portion of the tree's food-making potential and depletes the tree's stored reserves.

Topping stimulates undesirable "water sprout" growth. Topping stimulates the regrowth of dense, unattractive, upright branches (water sprouts) just below the pruning cut. Water sprout regrowth is vigorous.

Topping leaves large wounds. The branch wounds left from topping are slow to close and, therefore, are more vulnerable to insect attacks and fungal decay. An invasion by either pest can spread into the trunk, killing the tree.

Topping creates a hazard. Weakened stubs are more prone to wind and storm breakage because they generally begin to die back or decay.

Topping injures bark. Increased sun exposure on trunk and branches can lead to severe bark damage.

Topping disfigures trees. Ugly branch stubs, conspicuous pruning cuts, and a broom-like branch growth replace natural beauty and form. Topping also reduces the real estate value of trees, while a correctly trimmed tree increases in value at each pruning.

Why are trees topped?

Some homeowners and unprofessional tree pruners practice topping whenever trees reach an undesirable height. They mistakenly believe that topping will reduce the storm hazard of falling branches, when in fact, topping has the opposite effect. People also top trees when they interfere with utility wires, buildings, solar collectors, or sunny garden area.

Selection of trees that only reach desired maximum heights eliminates severe pruning later. If you must prune a tree heavily every five to seven years, the tree is too large for the site. Replace it with a smaller species.

The National Arborist Association considers topping an unacceptable practice and advises against it. Unfortunately, even some legitimate tree service companies indiscriminately top trees. Before selecting a tree service, find out which companies advocate topping and avoid patronizing them.

What are the alternatives?

To avoid topping, newly planted trees should be properly pruned to develop a good branch structure as they grow. When a mature tree's height must be reduced, an alternative to topping is "drop-crotching."

Drop-crotching is a type of thinning cut that reduces a tree's size while preserving its natural shape. To drop-crotch, lateral limbs are pruned where they join side branches. The center leader is cut back to a large diameter secondary branch so that a modified leader remains.

This type of thinning cut stimulates growth throughout the tree and discourages water sprout development.

Can topping be corrected?

A professional arborist can improve the condition of a tree, even after it's been severely topped and shows heavy water sprout regrowth. As the water sprouts being to gain caliper, they can be selectively "thinned out" using properly placed branch collar cuts. New growth can be directed outward to expand and round out the crown.

This process will need repeating for a few years. The scars, both physical and visual, will never completely disappear.

A wiser alternative to topping is careful selection and training of your young trees. Avoid topping altogether. Allow your trees to realize their full potential for health and beauty in the landscape.