Topping Trees Bad Practice

Amy Aldenderfer, County Extension Agent for Horticulture

 

Topping damages hundreds of trees each year in Kentucky. Many people are unaware of the detrimental effects of topping. Trees are subjected to a number of stresses during their lifetime. Topping is also a form of stress, but it is a stress that can be avoided.

Topping involves drastic removal or cutting back of large branches in mature trees leaving stubs. Topping can make a tree hazardous and reduce its life. This practice is frequently the result of trying to manage trees incorrectly planted under power lines or too close to structures.  Site selection must always be considered before planting in order to provide the tree with sufficient room to grow.

Some homeowners believe that stimulation of new growth associated with topping is actually beneficial to the tree. Although the tree appears rejuvenated with new foliage and branches, this only serves to mask the real damage.

Trees are mistakenly topped, under the best of intentions, to remove potentially hazardous dead and diseased branches. Unfortunately, topping indiscriminately removes healthy and unhealthy limbs. Problem limbs are best removed by selective pruning instead of topping.

In some situations, removing large limbs may be necessary; however, correct pruning alternatives such as proper early training, selective thinning out of branches and limbs, or whole tree removal should be considered and adopted.

Removing much of the tree canopy upsets the crown-to-root ratio and cause serious interruption of the tree's food supply and exposes bark to the sun. A 20-year-old tree has developed 20 years’ worth of leaf surface area. This leaf surface is needed to manufacture sufficient food to feed and support 20 years’ worth of branches, trunks and roots.

Removing the tree's normal canopy suddenly exposes bark to the sun's direct rays, often scalding newly exposed outer bark. Serve sun scald will cause the bark to split and obstruct the flow of nutrients. Topping not only cuts off a major portion of the tree's food-making potential, it also severely depletes the tree's stored reserves. It is an open invitation for the tree's slow starvation.

Large branch stubs left from topping seldom close or callus. Nutrients are no longer transported to large stubs and that part of the tree becomes unable to seal off the injury. This leaves stubs vulnerable to insect invasion and fungal decay. Once decay has begun in a branch stub, it may spread into the main trunk, ultimately killing the tree.

Topping removes all existing buds that would ordinarily produce normal sturdy branches and instead stimulates regrowth of dense, upright branches just below the pruning cut. The water sprouts or suckers that result from topping are not well integrated into the wood of the tree and because of their weak connections and vulnerability frequently break.  Large limbs then fall creating a dangerous situation that must be remedied by tree removal. 

Since water sprout regrowth is generally rapid and vigorous, a topped tree often will grow back to its original height faster and denser than a tree that has been properly pruned or thinned. This makes topping, at best, only a temporary solution to oversized trees.

Some tree species such as sugar maple, oak and beech do not readily produce water sprouts. Without the resulting foliage, a bare trunk results and the tree quickly dies. Deteriorating branch stubs, along with weak sucker growth, make topped trees highly vulnerable to wind and ice damage.

From an aesthetic aspect, topping disfigures the tree. Unsightly branch stubs, conspicuous pruning cuts and a broom-like branch growth replace its natural beauty and form.

Unfortunately, even some "knowledgeable" tree services indiscriminately top trees. Avoid patronizing companies that advocate topping.

Here is a list of trees for small spaces, under 25 feet tall: Trident Maple, Flame Maple, Box Elder Maple, small Japanese Maple cultivars, Tatarian Maple, Autumn Brilliance® Serviceberry, Fringe Tree, Kousa Dogwood, Winter King Hawthorn, Leprechaun™ Ash, Amur Maackia, various cultivars of flowering crabapple, Leonard Messel Magnolia, Star Magnolia, Snow Fountains® Cherry, Snow Goose Cherry, Weeping Yoshino Cherry, Ivory Silk® Tree Lilac, and various weeping tree varieties.      

For more information, contact the Hardin County Cooperative Extension Service by phone: 270.765.4121, email: Amy.Aldenderfer@uky.edu or on the web: http://hardin.ca.uky.edu/.  Educational programs of the Kentucky Cooperative Extension Service serve all people regardless of economic or social status and will not discriminate on the basis of race, color, ethnic origin, national origin, creed, religion, political belief, sex, sexual orientation, gender identity, gender expression, pregnancy, marital status, genetic information, age, veteran status, or physical or mental disability.

 

CLASS NOTES  Mark your calendars and register:

Veggies 101—March 21, 6 p.m.—$5—A perennial fav.  Growing your own veggies is easy when you have the knowledge and tools.  This two-hour class introduces gardening concepts for beginning gardeners

Plant This Instead of the Invasive One—April 11 6 p.m.—$5—Plants that get out of hand are a gardener’s worst nightmare.  Learn which plants will give you the same look as some of the most common, aggressive garden plants.

Butterflies of Kentucky—April 18, 6 p.m.—$5— Butterflies are the flying flowers in the garden.  Learn which ones you can attract to your garden with plants the caterpillars will eat.

Birds of Kentucky—May 2, 6 p.m.—$5— Of the 383 species of birds in KY How many can you recognize? We’ll talk about common and rarer birds that might be in your gardens. 

 How to Register: 

· Go to http://hardin.ca.uky.edu/content/line-class-registration to sign up for any class.  Then mail in your payment.

· Or call (270) 765-4121 and talk to the receptionist.  Then mail in your payment.

· You will be registered on a first pay, first registered basis.  All classes have a maximum number of participants.  When this number is reached, there will be a waiting list.

Payment for each of the Gardener’s Toolbox classes are required to be enrolled ONE WEEK prior to the class date. You will be registered on a first pay, first registered basis.

Cancellations will be fully refunded ONE WEEK prior to the class date. Please let us know as early as possible if you have to cancel, we probably have others on a wait list.

HOW TO GROW Classes: If you would like to attend the class but do NOT want the supplies, there is the option of not paying the class supply fee. Please notify the front desk when registering.