Giant Knotweed

Giant Knotweed (Fallopia Sachalinensis) is a relative of the more widely known Japanese Knotweed. Giant Knotweed stems grow 4-5 metres in a single season and bear large, alternate leaves up to 30 cm long with heart shaped bases.

Like its cousin, this plant also produces woody, knotted, bamboo – like stems. In summer it develops a cluster of small green-white flowers and seed is sometimes produced.

It is highly invasive, spreading from green plant fragment, rhizomes or root fragments. Plants can also grow through walls and concrete. It is less widely distributed in Ireland than Japanese or Bohemian Knotweed.

Image courtesy of King County Government – Noxious Weeds