Filling hole in a tree

Question

I have a large hole in a Birch tree. It’s filling with water and promoting rot. I want to fill it to keep water out. What is a good fill and procedure that will not further harm the tree?

Answer 1

Here is an article that you may find helpful: https://www.gardeningknowhow.com/ornamental/trees/tgen/patching-tree-hole.htm