This perennial dies back to below ground level each year in autumn, then fresh new growth appears again in spring.
Position: full sun
Soil: fertile, well-drained soil
Rate of growth: average
Flowering period: June to September
Hardiness: fully hardy
Huge, purple, thistle-like flowers from June to September held above enormous clumps of deeply-cut, silvery-green leaves. This magnificent, architectural plant is perfect towards the back of a mixed or herbaceous border. For the best results it needs full sun, lots of space and shelter from strong winds.
Garden care: Avoid the temptation to remove the faded flower-heads in autumn as they provide interest in the winter garden. Where temperatures fall below -15°C (5°F) protect the crown of the plant with a dry winter, straw mulch.