Last year I planted a small Japanese maple. At the beginning of this summer...

Asked August 18, 2013, 11:39 AM EDT

Last year I planted a small Japanese maple. At the beginning of this summer it seemed to be doing quite well, but yesterday I noticed that the leaves appear to have powdery mildew. How should I proceed?

Baltimore Maryland trees and shrubs japanese maples powdery mildew

1 Response

It is quite possible that your Japanese maple tree is afflicted with powdery mildew. This is a foliar disease and only affects the leaves of the tree. It is not lethal. If weather conditions next year are more moderate, it may not occur again. There is no treatment that would be appropriate now. You cannot cure a fungal foliar disease once the symptoms are obvious. Fungal diseases can only be prevented by spraying the foliage with a fungicide before the symptoms appear and then continuing with additional applications every week or 10 days throughout the season. This is not practical for most homeowners. Good sanitation would be appropriate. Rake up and remove all the leaves that fall from the tree this year.
LS