Easily grown in any ordinary soil, but it grows best in a light loam. Tolerates heavy clays and light shade. Prefers growing in light shade. Survives but does not thrive in dry conditions. Prefers growing in a bog garden or in a soil that is unlikely to dry out. Plants are very cold-hardy, tolerating temperatures down to about -20°c. A polymorphic species, there are several named forms. The plant spreads freely at the roots and so is best grown in a large pot.

None known

Seed - sow spring in a cold frame and keep moist. The seed germinates in 2 - 6 weeks at 20°c. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in the cold frame. Plant them out into their permanent positions in the spring or early summer. Division in autumn. Cuttings of soft tips in summer in a sandy soil in a frame.

Margins of swamps, wet woods and rivers.