Possible rot in a maple tree
We have a large maple tree that has a 2 inch hole in its trunk, presumably where a limb once was. Recently, we had a tree service representative in our yard and, to my surprise, he took a small dead limb, stuck it in the hole, and moved it around inside the hole. Then, he said that there is some rot in the hole and I should spray Great Stuff (some kind of expandable foam) in the hole to contain it. Should I follow this advice? If not, would it be better to let the tree take care of itself or should I do something else to deal with the rot? Thank you.
We do not recommend wound dressings or fillings of any kind.
Way back it was common practice, but now we let trees seal off (compartmentalize) problems as best they can.
How pruning cuts are made can make a great deal of difference in whether the cut can heal well.
Here is our pruning publication: