Why is my royal red maple of 20+ years dropping a large amount of leaves?
Could the brown spots on the leaves in images 1& 2 be caused by a fungus? There is also a small amount of insect damage but it appears to be minor. Image 3 shows the vast amount of missing tree leaves. Would an organic mixture of baking soda and water sprayed on the leaves stop the fungus damage? Should I call a tree service to spray? Should I just let it run Its course and hope the tree will recover?
This may be maple anthracnose, a fungal disease. Many shade trees of various species had anthracnose this year after the prolonged wet period. This occurs occasionally and is rarely problematic.
Here is our website info on anthracnose: http://extension.umd.edu/hgic/shade-tree-anthracnose-trees