I have one that I've moved to several locations in my garden; however, it doesn't seem to be happy anywhere. In October, I'm going to dig it up and plant it in a pot. I think it needs lots of moisture and softer soil than what the ground in my garden provides.

Mine is in a large ceramic (glazed) pot in the shade, under both the high limbs of an oak tree and closely surrounded by the lower limbs of my neighbor's privet and a rhododendron in my own yard. It does well there. It also seemed to be happier when it was pot-bound. I tried to divide it this year and it has been pouting ever since, but in previous years it sent up glorious 6-foot stalks of bloom. It's tempting to say that it likes lots of moisture, because its large leaves respond well to watering, but I also feel this is a very drought-tolerant plant - at least when grown in shade.