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.


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


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.


Recommended approaches

If found in the environments listed below, please report to Auckland Council.
- Rural areas
- Mapped wetlands
- Properties bordering wetlands.
- within a flood zone of wetlands

For all environments, the recommended approaches are listed below.

Physical control

Manual removal: This is not recommended, as manual removal and disposal may spread the weed further as it regrows from small plant fragments. Auckland Council are carrying out trials on manual removal.


Biocontrol is currently not available for this species.

Community agrichemical control recommendations

No qualifications: Seek advice from herbicide stockists.

Basic Growsafe certified Foliar spray 200ml Glyphosate 360 + 10ml organosilicon/10L (backpack.

Certified Handler/Experienced agrichemical user: Foliar spray 10g metsulfuron-methyl 600 + 200 Glyphosate +10ml organosilicon/10L (backpack) Or Foliar spray 200ml Glyphosate 360 + 10ml organosilicon/10L (backpack)

* Apply chemicals as per instructions on the herbicide container.
* PPE gear should always be worn when missing and applying chemicals.

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.
Photo showing Chinese knotweed in flower.
Flowers are borne in inflorescences in autumn.
Photo credit: