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: any moist soil
• Rate of growth: fast
• Flowering period: June to October
• Hardiness: fully hardy



'Superba' is a vigorous, mat-forming semi-evergreen perennial whose leaves create a carpet-like effect beneath the pink flowers, which turn to crimson as they mature. Not to be confused with the similarly named Bistorta officinalis 'Superba', East Indian knotweed blooms during the summer and boasts excellent autumn foliage colour.



• Garden care:
  Incorporate a generous amount of composted organic matter or well-rotted manure into the backfill during planting. Once established, lift and divide congested clumps in spring or autumn. Cut back after it has finished flowering, or wait until late winter or early spring. Apply a mulch of composted organic matter every year.