Question
We have a beautiful large silver maple in our yard. We have had it carefully
pruned to remove some limbs. Where one large limb was removed, a hole
developed that is gradually growing closed.

Below the hole, a red-bellied woodpecker excavated a nest and raised a
family one summer. Now a couple years later, we see a new hole excavated
about a foot below the first hole.

Is this a sign that the tree is unhealthy? Do these holes harm or damage the
tree? We don't want to lose the tree, and we also want to provide good habitat
for the birds.

Answer
The woodpecker nests is a sign that the tree maybe hollow or at least soft in the middle due to decay fungi. The only real "health" issue maybe the lessening of the strength of the trunk from the hollow trunk. The holes will have little effect on the health. I would make sure the tree is fertilized each year to help with the health of the foliage and the living parts of the tree. The inner part (wood) is composed of dead cells and if a decay fungi gets in the fungi over time may hollow the tree. This does not effect the growing parts of the tree. fertilize with 10-10-10 fertilizer at the rate of 1 lb per inch of trunk diameter scattered around the tree and watered in good. Do this in the spring after the last frost date.