As nashoba has said cut off any affected parts of the plants and a couple inches below and above where you are seeing the mold to be safe, then after removing all the moldy spots dispose of them away from the garden and sterilize your scissors. And monitor the plant closely to make sure no more pops up. You don't want to harvest the plant too early because you'll end up losing alot of weight as most plants gain the majority of their weight in the last two weeks. And depending on when they went into flower the buds might not hav any significant amount of THC yet.