Plant Pathology Infobytes
January 7, 1999
Pruning Ice Storm Damaged Trees to Prevent Future Health Problems
Homeowners with ice storm damaged trees will probably want to go back and neaten-up the jagged remains of broken limbs left in the aftermath of the storm. While it may not be possible to reach all branches, it's important to carry out a proper pruning cut when possible to minimize the risk of invasion by decay organisms which could cause later tree health problems.
In the past, it was thought that cutting branches off flush with trunk was the best procedure. We now know that flush cuts actually harm trees by opening them up to fungal and insect attack, since these type cuts weaken a tree's natural defense against pest invasion. Arborists now recommend cutting branches only as far as the branch collar - the raised or swollen area at the base of the branch where it joins the trunk or a larger branch. It's important to leave the collar because growth hormones present in this tissue promote healing of the wound left as a result of pruning.
Because of its weight, a large limb could tear loose during pruning, cause bark stripping, and result in further injury. If the following pruning rocedures are followed the chances for this happening are minimized..
- Make the first cut on the underside of the branch approximately 6 inches to one foot out from the trunk. Cut about 1/3 of the way through.
- Make the second cut on the top of the branch, several inches out from the first cut cutting the branch completely through. Because of the first cut, the branch will fall without tearing any bark.
- Complete the job by cutting the remaining branch stub back to the collar.
- Don't bother about applying a tree wound dressing; research shows that tree paint serves little purpose.
Infobytes newsletter was written by the late Dr. Frank Killebrew, Extension Specialist.