Question
Hi  I'm wondering if there is anything I can do this year to help stop the spot next year. I have read that spraying oils in the fall, as with Roses, but these trees are 60-75-100' tall. I cant pick up every leaf as they fall and aren't we mulching all leafs with the lawn mower. The trees all seam healthy. I live just north of Detroit. Thanks Paul

Answer
That large of trees of is not really anything that can be sprayed on the foliage. It is not necessary to rake all leaves. Raking leaves or mulching them will cut down the amount of spores that will make new spots. The population of spots will depend on the weather when the spores are present. IF humid and warm there will be a better chance for more spots. BUT in any case the spots will not kill the tree and usually will not be bad two years in a row. Quit worrying about this.