RHS 
A perennial with upright, yellow-green, stem-clasping foliage. Terminal clusters of flowers appear in mid- to late summer, opening very dark purple, becoming paler and redder with age
0.1-0.5 metres
0.1-0.5 metres
| Season | Stem | Flower | Foliage | Fruit |
|---|---|---|---|---|
| Spring | ||||
| Summer | ||||
| Autumn | ||||
| Winter |
Fertile, humus-rich, leafy, moist but well-drained neutral to acid soil is preferred; although best in part-shade, if the soil is moist will do well in more open sites. Young growth is late, often not appearing until later in spring. Plant tubers 15cm deep in winter or early spring. Apply a deep winter mulch in colder areas
Propagate by seed in containers in a cold frame as soon as ripe or by division in spring
Deadhead after flowering
Slugs and vine weevil may be a problem
Generally disease-free, but may be susceptible to a virus