River Birch Leaf Dieback
I have a series of river birch trees (betula nigra 'heritage') that are afflicted with some type of blight or fungus (see pics). The new leaves are unaffected and then progressively burn around the edges as they age. There does not seem to be any spotting in the middle of the leaves, but progresses from the edges inward. If anyone can suggest a solution to this problem that would be great. Thanks very much.
Ada County Idaho
I don't really know, but here is a link to a pamphlet on birch care. https://www.na.fs.fed.us/spfo/pubs/howtos/ht_birch/ht_birch.htm. I must say though that when I look at the entire tree it doesn't look bad.