I have spots on many leaves of a red maple tree. Here is a picture showing the red and yellow bull’s-eye-looking spots.
What are they?
What do I do about it? Is this a do-it-yourselfer or do I need a pro?
Almost certainlt a fungal disease (although I’ve never seen one quite that regular or colourful on maples before).
It isn’t terribly serious - only if the infection is extremely severe (perhaps 50%+ of the leaf area affected) is the tree likely to be harmed by it, but it can look unsightly.
If is it just a few leaves and you can reach them, pick them off and burn them (this will control the spread of the disease, rather than eradicate it. Or maybe spray with some sort of fungicide.
If they are raised, kind of warty spots you may have leaf galls, a condition caused by mites which are basically harmless to the tree.
I couldn’t find any web pictures of galls that looked exactly like that.
I’d bet someone on this forum could conclusively identify the problem for you.
Ack!
They are Maple Eyespot Galls; ignore everything I said above.
Apparently it isn’t very serious and treatment is rarely necessary