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

• Position: full sun
• Soil: well-drained, moderately fertile soil
• Rate of growth: average
• Flowering period: May to June
• Hardiness: fully hardy
  
  A really arresting sight in May and June, when the violet flowers and cornflower-blue beards appear among sword-shaped, grey-green leaves. This may not be one of the fanciest irises around, but what it lacks in originality 'Mer du Sud' makes up for in quantity, flowering prolifically throughout early summer.
  
  Garden care: Plant shallowly with the upper part of the rhizome sitting on the surface of the soil, incorporating a low nitrogen fertiliser in the planting hole. After planting remove the uppermost third of the leaves to protect against wind-rock. In exposed areas stake with bamboo canes in early spring. Remove the stems after flowering from the base as this will concentrate the plant's energy into producing new rhizomes. Divide and replant about every three years.