A plant of the waterside, it prefers growing in a sunny position in wet soils or shallow water, though it will tolerate drier conditions if there is shade from the summer sun. It requires a deep rich slightly acidic soil. Grows well in heavy clay soils. Plants are hardy to about -20c. A greedy plant, inhibiting the growth of nearby plants, especially legumes.

Root - it must be well cooked. Some caution is advised, see the notes above on toxicity. Flower buds - raw, cooked or pickled and used as a caper substitute. Some caution is advised, see the notes above on toxicity. Young leaves, before the flowers emerge are eaten raw or cooked. Some caution is advised, see the notes above on toxicity. Older leaves, before the plant flowers, can be eaten if well cooked. Some caution is advised, see the notes above on toxicity.

Seed - best sown as soon as it is ripe in a cold frame in late summer. Stand the pots in 2 - 3cm of water to keep the soil wet. The seed usually germinates in 1 - 3 months at 15°c. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in a tray of water in a cold frame until they are at least 15cm tall. Plant them out into their permanent positions in the summer. Division in early spring or autumn. 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 summer or following spring.

Sub-alpine and alpine swamps and marshy meadows.