Ask a Consulting Arborist Q&A: Bark and Trunk Concerns

Q: Bark on walnut tree is peeling off after being hit by a car. What can I do to help it?

Thursday, April 21, 2016  

Q: Someone crashed into my beloved walnut tree. In at least two different places, a lot of bark is missing and some bark is hanging on. One area is about 3 x 3 feet, and the other is 3 feet long and skinnier with bark hanging on, but broken and pulled mostly away from the trunk.

As seen in the pictures below, there is additional damage under the vines. I have been letting the vines grow on the side of the tree thinking they would protect the wound from potential damage, but I'm wondering if I did the wrong thing in doing so. I noticed a dark wet-looking area around the place where bark was missing. Can I do anything to help it? I love this tree, and so do the neighborhood squirrels.


A: Looking at the pictures, it is quite difficult to see the extent of the bark damage below the vines. Also, I did not see any cracks in the freshly exposed wood just below the bark. If the damage is no more extensive than it appears in the photos, I would not expect there to be much immediate impact on the health and vigor of your tree. The big concern here is the potential for the exposed wood to become infected with decay fungi, causing the wood components to be dissolved. If decay becomes severe, the tree trunk can become structurally unstable years after decay sets in. Over time, the cumulative effects of the impact may cause both structural and health problems for your tree. Another concern is the loss of amenity value your tree has sustained as a result of the impact. If you know who caused the impact to your tree, you may be able to recoup the lost value of your tree benefits by collecting any damages you are entitled to. You should have a Registered Consulting Arborist examine the tree to provide you with a prognosis and an appraised value of the damage. Choose someone who is both a skilled plant health care professional and someone who is very familiar with Council of Tree and Landscape Appraisers (CTLA) Guide for Plant Appraisal.

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Responder: Marty Shaw, RCA #470, Franklin, TN