The plants are in Southern Illinois, so they have a lot of clay and humidity, but the dying off starts before it gets to the high humid days of summer. They usually get quite a bit of rain in the spring so a lot of moisture is held because of the clay. It doesn't seem to affect the white and blue autumn joys that are planted close by. Mom did take some cuttings last year and moved to a new bed that has a lot more aeration and compost to see if that would make any difference, but they are once again starting to die back.
