Borer Damage to Fruit Trees Best Corrected Now

Q. I have a peach tree planted in 1998 with the bark lifting from the trunk easily. My gardener doesn't know what this is or how to treat it. Can this tree be saved?

A. This is borer damage to your peach tree and is the usual reason for their death at an early age. The damage is done by an immature stage of a beetle. Some people called them "worms" but they are properly called larvae.

The adult female beetle flies looking for a mate during the spring and summer months. Once she mates than she lays eggs on many different kinds of trees including fruit and many landscape trees and shrubs.

It appears she is attracted to trees damaged by a lack of water or intense sunlight on the limbs. Reducing damage to the tree because of intense sunlight is thought reduce damage by boring insects.

This is done by “whitewashing” limbs, particularly on the upper surface, with a mixture of white latex paint and water in a 50/50 mix.

Whitewashing these limbs reduce, but do not eliminate , damage created by intense sunlight. If you look closely you will see most of the damage is either on the upper surfaces of these limbs or on the sides of limbs that are facing south or west. These directions are where the most intense sunlight comes from.

When pruning peach trees in particular, which seem to be very susceptible, try not to prune so much out of the tree that it lacks the shade needed to protect the limbs from intense sunlight. Here are a couple of postings on my blog.

http://xtremehorticulture.blogspot.com/2015/08/identifying-their-damage-and.html

http://xtremehorticulture.blogspot.com/2014/02/mechanical-control-of-borers-in-fruit.html

Trees that get borers sometimes go into a death spiral; borers continued to attack these limbs or more limbs, limbs die and open the canopy for more intense sunlight which causes more damage which attracts more borers.

There are no safe insecticides or chemicals that you can apply to these trees to cure the problem. The best approach I have found is removing the damage from the trees with a very sharp knife and let the tree heal on its own.