Persicaria chinensis

Chinese knotweed

Also known as:

Liane rouge, red bush, huo tan mu

Family: Polygonaceae

Origin: Asia

Dense clump of Chinese knotweed.
It is a fast-growing vine that smothers plants and trees.

Regional Pest Management Plan (RPMP) status

  • Unwanted organism

View more about the RPMP statuses

General description

Perennial, scrambling, mat-forming, herbaceous vine < 1 m tall or climbing to < 10 m. Rhizomes are stout. Leaves are ovate, lanceolate or elliptic, < 16 x 8 cm and smooth or covered in stiff hairs. Flowers are small, white/pink and borne in inflorescences in autumn.

What you need to know

To help protect our environment:

  • You must not breed, distribute, release or sell Chinese knotweed. As Chinese knotweed is an Unwanted Organism, these restrictions apply within the Auckland region and across the whole of New Zealand.

If you see Chinese knotweed anywhere, you must report it to the Ministry of Primary Industries on 0800 80 99 66.

Habitats

Forests, riparian margins, grasslands, disturbed sites, crops, roadsides, urban areas.

Dispersal

Seeds dispersed by birds. Vegetative spread from stem and root fragments. Human-mediated dispersal through dumping of garden waste and deliberate plantings.

Impact on environment

Forms dense mats, smothering native vegetation and suppressing seedling recruitment.

Control

Recommended approaches

Do not attempt to undertake control of this species. The Ministry of Primary Industries will carry out the control of this species.

Caution: When using any herbicide or pesticide please read the label thoroughly to ensure that all instructions and safety requirements are followed.

New growth on Chinese knotweed.
Chinese knotweed can grow as a scrambling vine or as a shrub.
New shoot of Chinese knotweed branching off the vine.
The leaves are soft and wavy-edged, it has pinkish stems and cream/pink flowers.