Easily grown in any moderately good garden soil that is well-drained. Prefers a soil rich in organic matter. Plants are hardy to about -10°c but in areas with prolonged cold winter temperatures it is best to give the plants a protective mulch of evergreen branches or dry bracken. Cultivated as a medicinal plant in Szechwan, W. china. Hybridizes freely with other members of this genus.

None known

Seed - sow spring or autumn in a cold frame. When they are large enough to handle, prick the seedlings out into individual pots and plant them out in the summer' Division in spring or autumn. This should be done every 3 - 4 years in order to maintain the vigour of the plant. Very easy, larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the spring.

Wet slopes and sometimes on sphagnum bogs in high mountains, C. and N. Japan. Stony ground in mountain valleys.