Severe weather is a fact of life in Oklahoma, with storm-related damage a major impediment to maintaining healthy trees. Ice and wind have the power to snap limbs and large branches leaving landscapes littered with storm-damaged trees. While we cannot control the weather, we can implement measures to manage stormdamaged trees and minimize risk to people and personal property. This fact sheet is designed to address many common questions posed by property owners following storm damage.
Rehabilitation or Removal?
The decision to save or remove a storm-damaged tree is usually a subjective one, with the choice relying more on opinion than fact. Emotions often are the overriding factor in the decision process, especially when the damaged tree is a very large, old, or 'heirloom' tree. Here are a few points to keep in mind when deciding whether to rehabilitate or remove your storm-damaged tree:
Use common sense and ask yourself if the damage has perhaps rendered this tree hazardous? In other words, does it now look vulnerable to any additional wind or ice event that could cause it to fall in its entirety or at least "drop" one or more large branches that could damage nearby property or prove fatal to people and pets?
Educate yourself as to the potential growth rate and commercial availability of replacement trees.
Even if the tree can be salvaged, assess whether it will ever look "right" again with some semblance of symmetry.
If significant bark has been ripped or loosened from the trunk (Figure 1), be realistic about the tree's potential for attack from opportunistic microorganisms and damaging insects outlined later.
Do Not Top Trees
Topping or dehorning permanently ruins the structural integrity of the tree. This practice leads to adventitious or epicormic shoots (shoots or new growth that is weakly attached to main scaffold branches or limbs). This adventitious growth is likely to break a way from the tree during a future ice or wind storm. Besides negative impacts on structural integrity, such severe pruning practices compromise the attractiveness of the tree.
Wound Response and Pruning
Proper pruning is critical to facilitate quick wound response by the tree (compartmentalization). Compartmentalization results in the isolation of microorganisms or barriers to insects to prevent them from causing further damage to the tree. Trees initiate compartmentalization in their sapwood very quickly following injury. This helps combat infection by invading pathogens and insects.
Compartmentalization of wounded sapwood results in th e complete isolation of the invading organisms, resulting in formation of the "reaction zone." Heartwood decay occurs up to the sapwood reaction zone. Some organisms can detoxify reaction zone compounds, causing the continuous retreat of heartwood, and trigger the formation of a new reaction zone in the sapwood (build-up of callus tissue).
Wound dressings (i.e., pruning paints) after pruning are no longer recommended. Wood has the ability to quickly form barriers to pathogen and insect invasion. In some cases, researchers have determined pruning paints are counterproductive to wound closure.
ow to Prune
First, remove all broken or damaged limbs, which are the most hazardous to people and property. Never remove more than one-third of the branching system of any tree. If more than one-third of the branches have been damaged by wind or ice, consider tree removal rather than attempting to salvage the tree. Cut limbs back to a lateral branch that is nearly one-half the diameter of the removed limb. Do not leave stubs as this is unsightly. To avoid further damage to the tree, use the three-cut pruning method.
If you have any questions about your trees or other landscaping concerns as you clean up after the tornado, please give the OSU Extension a call at 580-795-3563.