I watered my mint over the leaves all summer just to freshen it up: the day I turned one leaf over, it was already too late
Mint rust hides on the undersides of leaves, thriving in the moisture from overhead watering long before you notice any problem. By the time orange pustules appear on top, the fungus has already established itself for weeks. A simple change in watering method—applying water at the base instead of overhead—can prevent this destructive disease entirely.