Question
Stressed Maple
We live in La Crosse, Wi. and experience extreme temperatures on both ends of the scale. Our maple lost a large lower branch in a storm a few days ago, the first time this has happened. We had always questioned the health of the tree due to what we believe are very large (and growing)frost cracks on both the northeast and southwest sides of the tree. After removing the limb, we noticed more "cracks" running half way up the tree on the southwest side. The top of the fallen limb appears blackened, possibly rotting? The lower leaves have always had bladder gall, but now, looking at leaves farther up, we see blackened spots on the leaves that I believe to be anthracnose. Any suggestions on reviving our stressed out tree?
AnswerLooks like sun scald damage which can be a problem on thin barked trees like Maple. I would fertilize the tree with 10-10-10 fertilizer at the rate of 1 lb per inch of trunk diameter scattered around the tree and watered in good. Apply the fertilizer just before a rain storm and you will not need to water. This will increase the health of the root system and the foliage.
Then I would spray the area with an insecticide called Merit or Onyx. These insecticides will prevent borers from entering the wound and causing more damage to the tree. You can remove the loose bark around the wound but make sure you do not cut bark that is tight on the wood. The tree is trying to heal over the wound but the wound is too large and I would expect that over time the wood in the trunk will be attacked by decay fungi and become hollow. Not anything you can do to slow the decay fungi except keep the tree health by fertilizing it. I would fertilize now and again in the spring.
