Question
QUESTION: Our maple tree was hit by high winds 3 yrs ago, lost major limb. tree surgeon who cut and cleaned up property said not to seal wound with tar, it would heal itself. starting last yr noticed NO healing and wood chips at base of tree and wound is now a hole. NOW this spring, past few days many woods chips, assumming comming from hole/wound. Squirl/Ants/Bores? PLEASE HELP. From South burbs of Chicago

ANSWER: He is right it does not need to be treated with a wound dressing. I would treat the hole with an insecticide called Merit. This will kill the borers in the wood. And if it is a animal it will discourage the animal also. Check with your local nursery for Merit.

The hole can be filled with foam installation this will close the hole but any fungi in the wood will continue to grow and over time the tree may become hollow.

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QUESTION: Serious?!
Soundss like we will loose tree. .I'll get the MERIT and fill with foam, (you mean that expandable house foam?, which type?) The tree is our main shade in front & would not enjoy loosing it!
Thanks very much in advance of your respense!!!!
Roger

Answer
No I do not think you will lose the tree. The living part of the tree is the layer of cells just under the bark called the cambium layer. The rest is the woody cells that are dead. When the bark is broken by a wound decay fungi can get into the woody cells and over many years can decay the inside of the tree. If the tree is healthy this decay process is very very slow. BUT even if the tree becomes hollow by the decay it will live just fine. The first sign of the tree having extensive decay will be limbs breaking during wind storms and these will also be hollow or at least the middle of the wood in the limb will be soft. The way to slow this down is to keep the tree heathy--I would once a year in early spring fertilize the tree with 10-10-10 fertilizer at the rate of 1 lb of fertilizer per inch of trunk diameter scattered around the tree and watered in good. Fertilize just before a rain storm and you will not need to water it in.

Yes, The foam is the expandable house foam. But using it is for cosmetics and not as a treatment for the decay. There is not a way to treat the decay except to keep the tree growing healthy. If you use it make sure it does not extend out further than the bark.