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
• Rate of growth: average
• Flowering period: June to July
• Hardiness: fully hardy
  
  Spectacular spires of semi-double, deep-blue flowers, each with a white eye, appear in June and July above deeply lobed, mid-green leaves. 'Blue Nile' is a brightly coloured delphinium for the back of a sunny, well-drained border and make excellent and long-lasting cut-flowers.
  
  
• Garden care: For best results, plant in an open spot with fertile, freely-draining soil and protect the young foliage against slug and snail damage. During the growing season, apply a seaweed or balanced liquid fertiliser every 2-3 weeks. While wearing gloves, stake the emerging flower spike with a stout bamboo cane and tie it in as it grows. Cutting back the faded flower stems to a flowering side shoot will help encourage a second flush of flowers.