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

• Position: full sun or partial shade
• Soil: moist but well-drained soil
• Rate of growth: average
• Flowering period: May to July
• Hardiness: fully hardy
  
  These easy to grow perennials will create a massive impact when their dark blue flowerbuds open to reveal their star-like, steely blue flowers in late spring and summer. The flowers are loosely held, in slightly pendulous clusters on top of tall stems bearing slender, tapering leaves, which turn interesting shades of yellow before dying back in autumn. The flowers can be cut and used in floral arrangements, but to stem the milky sap the end of the stems should be seared in a flame before popping in a vase.
  
  
• Garden care: if the plants are starting to look floppy after they have flowered, they can be cut back to new basal foliage. Alternatively, they can be givven a lighter trim, cutting them back to form neat domes. Lift and divide (when necessary) in Spring or Autumn.