This perennial is semi-evergreen so it can lose some of its leaves in winter. In colder regions or more exposed gardens, it may lose them all, but then fresh new growth appears again in spring.

• Position: full sun or partial shade
• Depth of water: 5-25cm (2-10in)
• Soil: reliably moist or boggy soil
• Rate of growth: fast-growing
• Flowering period: July to August
• Hardiness: fully hardy
  
  Sulphur yellow flowers, often with brown markings, appear from midsummer amongst the upright grey-green leaves of this vigorous water marginal. This native, evergreen yellow flag iris was once commonly found on marshy land and riversides and is ideal for planting at the margins of a large lake or pool. It also flourishes in deep, reliably moist soil that has been enriched with well-rotted organic matter. Great for wildlife and bog gardens, too.
  
  
• Garden care: Plant out in reliably moist soil, or pot up into a pond basket and place at the margins of a pond. Once established, divide overly large plants every three to four years.