Scientific Name: Fallopia japonica ( syn. Reynoutria )
Common Name: Japanese knotweed
Family Name: Polygonaceae
Origin: S.E. Asia / Japan / China
Hardiness Zone: Zone 5: (-29 to -23 °C)
Plant Type: Herbaceous perennial, Invasive plant, Shrub - deciduous, Weed (horticultural)
Mature Size: 2 - 3m x 7 - 10m (height x width)
Habit: Upright
Form: Oval - vertical, Round
Texture: Medium - coarse
Landscape Uses:
Exposure: Full sun, Part sun/part shade, Filtered shade, Deep shade
Soil or Media:
Leaves: Simple, Alternate, Soft flexible, Glabrous, Ovate, Entire
Flowers: Panicle, White, Aug-Sep
Fruit: Capsule, White, Brown, Sep-Oct
Key ID Features:
Stems hollow, bamboo-like, arising from rhizomes; leaves have a straight base (truncate), apex with an abruptly pointed tip, undersides have small ridges or bumps on veins or margins, up to 17cm long; florets creamy-white, 2-3mm wide, in panicles arising from leaf axils that are about 15cm long. (Giant knotweed, F. sachalinensis, is very similar but larger).