gardenia TREE has hole in trunk

Question

The gardenia “tree” has a diameter of 8 inches, 3 feet of trunk before foliage. In the middle of the trunk, there is a hole almost like hollowed out. It is moist and flaky like termites but no termites! What would I fill it with to save it from any further damage?

Answer 1

I wouldn't advise filling the hole until a determination is made on what caused the hole. How big is the hole? Are there any signs of insects? Besides the hole, is there anything else unusual on the tree - such as the leaves for instance?