I have both red and yellow forms and grow them in pots that stand in almost full sun, and always in the weather. I do not disturb them so the clumps are well packed in the pots. In fact the red clump has cracked its pot and now stands, undisturbed, in another pot. I feed them throughout the growing season. We get frosts too, but no freezes. The yellow is less vigorous but o/wise both flower quite well.