Houttuynia

General description

Deciduous or evergreen groundcover herb < 1 m tall. Stems are creeping. Leaves are heart-shaped, < 7 cm long and green or variegated green/cream/yellow/red. Flowers are small, white and borne in spikes in summer.

What you need to know

To help protect our environment:

• You must not breed, distribute, release or sell houttuynia. As houttuynia is a National Pest Plant Accord species, these restrictions apply within the Auckland region and across the whole of New Zealand.
• You must not plant houttuynia within the Auckland region.

Habitats

Damp and shady habitats, wetlands, riparian margins, forest, shrubland, gardens.

Dispersal

Possibly sets seed. Vegetative spread from rhizome or stolon fragments. Human-mediated dispersal through dumping of garden waste and deliberate plantings.

Impact on environment

Rapidly forms dense colonies. Potential to suppress native seedling recruitment and alter canopy composition.

Control

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 other environments, the recommended approaches are listed below.

Physical control

Manual removal for small infestations can be effective before producing seeds. Replanting the area with desirable plant species suppresses regrowth. Monitoring the area and removing any seedlings before they set seed will work towards permanent control.

Plant parts requiring disposal: All plant parts.

Disposal options: Green waste bins or landfill.

Biocontrol

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 per 10L water + 10ml penetrant

Certified Handler/Experienced agrichemical user: Foliar spray 5g metsulfuron-methyl 600 + 10 ml penetrant/ 10L water. For infestations where exposure to a water body is likely to occur, foliar spray 200ml Glyphosate 360 per 10L water + 10ml penetrant

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