Herbaceous perennial to 90cm tall, with deeply divided, glossy dark green leaves and erect, tapering spikes of hooded, violet-blue flowers in late summer and autumn
Position
Soil Types
Max Height
0.5-1 metres
Max Spread
0.1-0.5 metres
Herbaceous perennial to 90cm tall, with deeply divided, glossy dark green leaves and erect, tapering spikes of hooded, violet-blue flowers in late summer and autumn
0.5-1 metres
0.1-0.5 metres
| Season | Stem | Flower | Foliage | Fruit |
|---|---|---|---|---|
| Spring | ||||
| Summer | ||||
| Autumn | ||||
| Winter |
Grows best in deep, cool, moisture-retentive soil in partial shade, but will also tolerate most soils and full sun if soil is humus-rich and protected with mulch to ensure that it is moist throughout the growing season; use protective gloves
Propagate by division in autumn or late winter to maintain vigour but plants may be slow to re-establish. Use protective gloves when handling any part of the plant
No pruning required except cutting back dead stems; use protective gloves
Generally pest-free but may be susceptible to aphids
May be susceptible to fungal stem rot, powdery mildews, and Verticillium wilt
The new app packed with trusted gardening know-how
Download app