By Dan Rahn
University of Georgia

Ever heard a tree scream? You might have if you'd listened closely and your lawn mower hadn't been so loud.

Volume XXX Number 1 Page 9

Jim Midcap, an Extension Service horticulturist with the University of Georgia College of Agricultural and Environmental Sciences, says trees planted in turf areas are always in danger of what he calls "power mower blight."

"Power mower blight is caused mostly by well-meaning, dedicated turf-clippers who vow to cut every blade of grass and not resort to such things as hand-held shears," Midcap said. "In close-quarters combat with a power mower, the tree generally loses."

Trees may not scream very loudly, but that doesn't mean the wounds gashed open by lawn mowers, and sometimes power trimmers, aren't real injuries. The gouging edges of mowers can seriously hurt trees, especially young ones.

Asking for trouble

"This wounding lays open sensitive inner tissue and can allow insects and diseases to attack," Midcap said. "Insects, in fact, will generally attack a tree in poor health. And creating an open wound is asking for trouble."

A jagged wound will heal poorly, he said. It will allow the tree's vigor to decline and make it more susceptible to such stressful times as drought or extreme cold.

What really makes power mower blight so bad, Midcap said, is that it's always avoidable.

"You just need to take precautions to protect the tree," he said. "Three small wooden or steel stakes or some type of short fencing placed close to the tree trunk will help fend off the cold steel."

Better idea

But perhaps an even better way to protect the tree, he said, is to mulch under the tree's drip line.

"This will define the mower area," he said. "It will modify the root zone environment under it, too, by keeping it cool and moist in the summer."

Mulching helps three ways:

1. It protects the tree from the mower.


2. It helps create a healthier environment for the tree.


3. It enables the dedicated clipper to cut every blade of grass and keep that perfectly manicured look around the tree.

Ground pine or hardwood bark, pine straw and leaf mold, or compost, are all good mulches, Midcap said. Just place a 2- to 3-inch thickness of the mulch under the tree.

Expand the mulch area as the tree grows if you like. But don't use too much. Most weeds and encroaching turf can be easily controlled with herbicides.

"Mulching, staking or fencing young trees around your lawn isn't a lot of work," Midcap said. "But it can make a lot of difference in the health of your trees."

(Dan Rahn is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)