QuestionI read your response to a question on 3/2 and 3/3 regarding compartmentalization of tree holes. However, in your last sentence you listed some "poor compartmentalizer" trees, one of which was a Hackberry. I happen to have a Hackberry in my yard that has a hole. It has a divided trunk and is cabled to give it assistance against wind. One of those trunks has a hole in it, likely from improper pruning before I bought the house. What do you suggest be done with holes in trees that are poor compartmentalizers?
AnswerThere is not much that can be done except to keep the tree growing healthy by adding fertilizer once a year. If there is a hole in the limb stub then the tree is hollow or at least the wood decayed in the trunk below the hole. Depending on the size of the hole--you can seal the hole in the branch wound by applying an installation foam into the hole and sealing the outer part. This is just cosmetic and will not help or hurt the tree. IF the hole is large you may have to add some screen wire just inside the hole so the foam will have something to stick to. Sealing the hole will stop water from entering BUT will also seal in moisture and will not stop the decay fungi. However, there is really no reason to fill a cavity other than for aesthetic reasons; it doesn't improve the trees health and doesn't offer any added support.
