Published on 01/27/00

Pines Not as Resilient To Ice Damage as Hardwoods

The winter storm that swept across north Georgia last week covered trees with an icy overcoat. Now homeowners are cleaning up fallen trees and broken limbs.

Thousands of trees are lost each year as a result of ice, wind and lightning damage, says a University of Georgia forester. The resulting annual property value loss in Georgia is estimated at more than $10 million. This doesn't include future liability costs.

"When hardwood trees are injured, a branch will break off, there will be some decay and maybe a weak insect attack," said David Moorhead, a professor of forestry with the UGA Warnell School of Forest Resources. "The damage usually won't kill hardwoods because the trees have such a good reserve in the root system."

Pines Not So Lucky

Pine trees are another story.

"If the ice storm caused your pine trees to lose a big section of the top or the main stem, you probably don't have many alternatives other than taking the tree out," Moorhead said. "Pine trees don't store a lot of food in the root system. So when they get injured, they don't have as much to fall back on."

Besides injuring the tree's structure, a large break in a pine tree's top opens a virtual buffet for harmful insects.

Beetles Big Problem

"The pine resin starts to come out and sends an open invitation to bark beetles," Moorhead said. "They're extremely hard to control, and there aren't any really effective sprays."

Bark beetles fly in, bore through the tree's bark and lay eggs underneath. There the larvae form feeding galleries and introduce a fungus called blue stain. This causes the tree to dry out and eventually die.

Some insecticides can control bark beetles, Moorhead said. "First you'd have to cover the entire tree to the point of wetting, and it will provide some protection," he said. "But with large trees that's not very practical."

Broken Branches Less a Problem

If the winter ice storm left your pine trees with just broken branches, the prognosis is much better.

"Properly prune the branches back to the whorl or main stem," Moorhead said. "Then you can do a good job of keeping that tree healthy. You'll need to clean up and prune off any broken branches without destroying the form of the tree."

Bark beetles are active year-round, but more so in warmer weather. "As soon as it warms back up and we get days in the 50s and 60s, we'll start to see the bark beetles coming out," Moorhead said.

To learn more about trees and storm damage, contact your county Extension Service office. Or check the UGA Extension Forest Resources publication, "Storm Damaged Trees," at <www.f>.

Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.