OKLAHOMA OUTSIDE
Assessing, deciding and managing storm-damaged trees By Sean Hubbard
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ertain trees can be a beautiful part of a home owner’s landscape; but after snow, ice and heavy winds strike, these very same trees can become an eyesore and a safety hazard. Following a storm, landowners should assess the damage and make the decision to remove damaged trees or to attempt to rehabilitate them. “It is often difficult to part with a large shade tree. Be realistic when making your decision,” suggests Kim Rebek, Oklahoma State University Cooperative Extension horticulture and landscape architecture assistant specialist. “As a general rule of thumb, if more than 50 percent of the tree crown has been damaged, the likelihood of survival is small.” Besides limb loss, peeled bark is another common type of damage that greatly impacts a tree’s longevity, because it opens the tree to infection from plant diseases. The first and most important step in pruning damaged trees is removing hazards such as hanging limbs, cracked branches and unstable trunks. However, improper care can create hazards in the future. “Do not top trees. Topping, or dehorning, per manently ruins the structural integrity of the tree,”
says David Hillock, extension consumer horticulture assistant specialist. “Topping will lead to adventitious growth, which is likely to break away from the tree during a future ice or wind storm.” Instead, broken limbs should be cut back to a branch that is at least a third the diameter of the branch being removed.
Because of its weight, a branch can tear loose during pruning, stripping the bark and creating jagged edges that invite insects and disease. That won’t happen if you follow these steps: A) Make a partial cut from beneath, at a point several inches away from the trunk. B) Make a second cut from above, several inches out from the first cut, to allow the limb to fall safely. C) Complete the job with a final cut just outside the branch collar, the raised area that surrounds the branch where it joins the trunk.
A branch should be cut just outside the branch collar, which is the swollen region where a branch connects to the trunk. Avoid cutting flush against the trunk, as this will create a wound that will not properly seal up. Larger branches should be cut using the threecut pruning method to avoid peeling bark. This process is demonstrated in the graphic on the left. Homeowners may also find pine trees that have damaged leaders, which is the central shoot and top vertical branch of the tree. “Without a leader, the pine will no longer grow upward but rather spread outward,” Rebek says. “Sometimes we can try to establish a new leader.” The first step in creating a new leader is to cut the broken shoot tip cleanly, just above a side branch. After attaching a sturdy stake to the tree trunk and allowing a section to extend beyond the broken tip, the largest lateral or side branch should be secured to the stake. This will direct the branch upward toward the sky, and over time, the lateral branch will become the new leader. Oftentimes storm-damaged trees are too large for property owners to rehabilitate themselves. A list of certified arborists can be found at www. forestry.ok.gov. OL
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