Clump River Birch Problem
I am not sure of the cause of the leaf spotting. It could be a disease or the environment. It would be best if we could talk about the situation. How old are the trees? Is the tree in full sun? The situation may take a lab analysis for me to determine the cause. There is no cost if I need the help.
Please call me at the Daviess County Cooperative Extension Service in Owensboro at 270-685-8480.