Grow in a well-drained, fertile, moisture-retentive soil in full sun. In cool regions, lift the plants in autumn, before the first frosts and store the crowns in trays of just moist compost in frost-free conditions until spring. In areas where temperatures fall no lower than -5˚C (23˚F) in winter, plants may be left in the ground and protected by a thick mulch over winter, carefully removing this in spring, after the risk of frosts has passed.
Once flowering is over in late autumn, cut the whole plant down to 20cm (8in) tall.
Propagate by basal
softwood cuttings from overwintered stools in late winter or early spring. Cuttings should be rooted in a loamless compost the surface of which is covered with dry sand and kept in a temperature of 16°C. Place in a cold frame after first rooting and protect from frost. Harden off in mid spring. Established clumps may be propagated by
division in spring.