Question
The answer to my last question tells me my maple has tar spot.  Will the leaves that fall with the spots continually reinfect the tree all summer and will they infect other maple trees in the same area or do they only release the spores the following spring?  Would it help to spray fungicide on the grass beneath the tree after raking up the leaves in the fall or in the spring before new leaves start?

Answer
Judy:
The sexual spores(ascospores) that are produced in the spring are infectious. Rake up/destroy fallen leaves before spring arrives. Asexual spores produced during the summer are not infectious. Not useful to spray the ground w/ fungicide. Raking is good. If you want to spray the tree, timing and coverage is essential.

Regards
Steve