tree limb fell off 100 plus year old tree

Question

We had a limb (the size of a tree) fall off of our 100 plus year old tree. It was about a third of the tree. We had it cleaned up but was wondering how to treat the wound. We were told to buy from Lowes or Home Depot a “tree spray” to cover the wound. There is a little hole where water would gather and thought we should spray a non chemical foam into the hole to keep water from pooling. What are your thoughts?

Answer 1

Cut the wound so that it is as flush as possible. The less jagged the wound, the better it heals. If you still have a hole, use a metal or plastic flap to cover it and keep out water and animals. Do not fill it. The reason is that once you fill it, you will not be check for rot every so often, which can invade the wound.

Other than that, just leave it alone. Sealing it can trap disease into the wound, so it is best to leave it unsealed. You can treat the wound with a fungicide, to help keep rot away.