I have an Eastern Red Maple, about 12 years old, which forms a very important screen. It has recently developed occasional squarish black spots on a few of its leaves. It is also looking slightly weak and the leaves are starting to turn to be at slightly odd angles. There is some insect damage at the outer edge of some of the leaves that results in a smoothing of the otherwise distinctive maple profile.
When we experience a very dark and damp spring, the result is a lot of disease on the trees. Once the tree is stressed by disease, the pests move in to the weakened plant. Warmer weather should help, but watch for drought stress when it does get hot in the summer, as the tree is weak. Mulch around the base of the tree to help retain moisture during these times and use a soaker hose during the heat of the summer. A little fertilizer will help also.
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