Most of my lilies are having yellowing leaves starting at the bottom that fall off. The problem is working it's way up the stems. When I've had this problem in the past, it's due to summer drought. We're definitely NOT having a drought. We've had 6 1/2 inches of rain so far this month. Anyone know what it could be? I'm afraid by June, I'm going to have nothing but sticks!

Deanna