Asked April 26, 2020, 3:25 PM EDT
We recently had part of a large willow tree break off and damage a Bloodgood Maple below it. We have removed several branches of the maple that were broken. There is one branch with a large gouge on the bark. The rest of that branch looks fine with beautiful, healthy looking leaves above the gouge. Is it OK to leave this branch, or should we remove it? Will it be an entry point for disease or insects? Thank you.
Washington County Oregon
It's unfortunate your bloodgood maple sustained such a large wound. With a wound of this size the most important considerations are: 1. structural support of the limb - has the limb been damaged to the point that it is unstable and might come down. 2. damage to the cambium layer which functions to move water and nutrients from the roots to the leaf canopy. If more than 25% of the cambium has been damaged the limb might not be able to recover and 3. the possibility of infection by bacteria and fungi with an open wound.
Wounds on trees heal by a process called compartmentalization. The cells surrounding the wound form special compounds that form a barrier to isolate the wound area. Discoloration and decay will no longer affect the area. New growth is stimulated to form and adds to the area. This article gives additional information and explanations, Trunk Wounds and Decay https://www.mortonarb.org/trees-plants/tree-and-plant-advice/horticulture-care/trunk-wounds-and-decay .
Having an ISA certified arborist evaluate your tree would be a good idea at this point. The arborist can come out to your house and examine your tree, and especially the wounded branch, then advise you on the best action to take. This site will give you names of ISA certified arborists in the area, https://pnwisa.org/hire-an-arborist/isa-certified-arborist-directory/. We recommend speaking with at least 3 arborists to find the one who will best meet your requirements.