I live in Northern California above the bay with clay soil. My two successive Plants of Chinese foxglove (Reahmannia?) grew well and doubled in size and got lovely flowers and new buds, but started dying suddenly and could not be revived. Leaves started dropping and wilting and then the whole plant dried up. One took a while to die. The second one did that in two days. I was watering regularly, though one day it suddenly got hot for the second plant, and I did not water it in the morning.