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: humus-rich, moist but well-drained soil
• Rate of growth: average
• Flowering period: July to August
• Hardiness: fully hardy
  
  Pointed leaves, which if grown in a sunny spot, have a deep purple flush, contrast well with the sulphur yellow flowers that start appearing from midsummer. This perennial will thrive in a moist herbaceous border or bog garden, where it will quickly form a colony. It will happily grow in full sun or partial shade, but the purple flush on the foliage will usually become less obvious (and the leaves greener) as the summer progresses.
  
  
• Garden care: Incorporate lots of organic matter when planting. Apply a generous 5-7cm mulch of well-rotted garden compost or manure around the base of the plants in spring and lift and divide congested colonies.