Belongs to: invasive aliens

Japanese knotweed Fallopia japonica

Non-native invasive

Best time to see: early Aug to end Oct

Key facts

An invasive and almost indestructible plant originating from east Asia and now widespread in Britain

Forms thickets 2m or so tall on road, railway and river banks and in any waste place

Grows from tiny fragments and illegal to transport except to licensed sites


Plant has reddish stems, making zig-zags, in large thickets about 2m tall

Flowers have white fluffy bits hanging down on thin stalks

Leaves large, almost triangular, with very pointed tips

© Tony Gunton

© Tony Gunton