This perennial dies back to below ground level each year in autumn, then fresh new growth appears again in spring.

• Position: full sun or light, dappled shade
• Soil: fertile, moist soil
• Rate of growth: average
• Flowering period: July to August
• Hardiness: fully hardy
  
  Perfect for the back of the herbaceous border, this statuesque perennial has purple/blue-flushed foliage and an abundance of lavender-purple summer flowers. The stems are tall and sturdy, which means that it rarely needs staking despite its height, and its light and airy silhouette ensures it never becomes oppressive.
  
  
• Garden care: In windy or exposed positions, it may need supporting with brushwood or garden canes. Divide congested plants as new growth begins in spring, although divisions may be slow to re-establish. Resist cutting back the old growth until early spring.