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
• Depth of water: 0-10cm (0-4in)
• Soil: deep, fertile, moist soil
• Rate of growth: average
• Flowering period: June to July
• Hardiness: fully hardy
  
  This adaptable perennial loves moist soils, so it can either be grown along the edges of a pond or in a bog garden. Spreading by creeping rhizomes to form a low clump of attractive leafy cover, it comes into its own in early summer when the sprays of small, bright blue flowers appear.
  
  
• Garden care: Plant straight out into reliably moist soil, or potted into an aquatic planting basket (using aquatic compost) and sink into shallow water. Divide overly large or congested clumps in spring.