I have a black and blue salvia planted in full sun. Recently, the
leaves, wich are supposed to be light green, started developing large black
areas. It's been storming here (Iowa City) for 2 week, so could this be
from too much water or wind damage? Could it be from underwatering (not
really likely) or disease? Will the black leaves regain their green color
or should i just trim them off? My basil and coleus had similar problems.

Thanks,
Adam