Deeproot Plant Base Online - Fallopia japonica

Plant Base Online (beta)

botanical name:
Fallopia japonica

common name: Japanese Knotweed
synonyms: Polygonum japonica
family: Polygonaceae

characteristics: perennial
height: 3.00m width: m
growth rate: very fast
growth habit:
leaf colour: green
flower colour: white
stem/bark colour: red & green
main period of interest: Autumn

growing conditions: full sun, part shade, shade, dry soil, moist soil, wet/waterlogged soil, clay soil, sandy soil, coastal
prefered soil pH: any
minimum temperature: -20°C
USDA zone: 5 to 9

description:
Notoriously invasive weed, this is a robust and vigorous perennial, spreading by creeping underground rhizomes which produce hollow, arching, reddish stems with large, pointed heart-shaped leaves. Forms dense thickets. Branched clusters of greenish-white, sometimes pink, flowers from late August to October. Rarely sets seed.

cultivation:
Prefers moist soils but appears to thrive almost anywhere.

usage:
Originally introduced to Britain as an ornamental plant and very occasionally still used as such, particularly in difficult locations where adverse conditions restrict its spread.

other notes:
Native to Japan but naturalised in other areas, including Britain, where it is common on waste-ground, road verges, by railways and streamsides.
Once established it is very difficult to eradicate.