Thanks for all the input! I remembered after reading it that I had found it as a control for rust after all, but that was so long ago that I don't remember the dosage, does someone know? The plants are healthy except for these orange/rust colored stains that seem to weaken that part of the leaf, I think that is rust disease. I am giving them compost as fast as I can get to it (which, at 72, is not as fast as I would like).