An erect, branching biennial with green foliage, and cone-like heads of blue flowers surrounded by spiny, silvery-white bracts appearing in summer
0.5-1 metres
0.1-0.5 metres
| Season | Stem | Flower | Foliage | Fruit |
|---|---|---|---|---|
| Spring | ||||
| Summer | ||||
| Autumn | ||||
| Winter |
Grow in dry, well-drained soil that is poor to moderately fertile. Full sun is essential. Tends to be a short-lived perennial but it self-seeds readily in the right conditions
Propagate by seed. Sow seeds onto moist but well-drained peat-free seed compost and cover lightly with vermiculite. Keep at a temperature of between 18-22°C
Although you can cut back flower stems after flowering the seedheads are a very attractive feature so are usually left over winter
May be susceptible to leaf and bud eelworms, and slugs and snails
May be susceptible to root rot and powdery mildews
