Artillery plant

General description

Perennial groundcover herb < 50 cm tall. Mat-forming and stoloniferous. Stems are square and densely hairy. Leaves are on a long petiole and are mint-like, < 8 x 6 cm, opposite, aromatic, pointed and coarsely toothed, with silver/grey patches on top and a hairy underside. Flowers are yellow, hairy and tubular, and are borne in dense axillary whorls in summer – autumn.

What you need to know

To help protect our environment:

• You must not breed, distribute, release or sell artillery plant. As artillery plant 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 artillery plant within the Auckland region, unless you are transferring an existing plant on your land to another location within the boundaries of the same property.
• You must destroy any artillery plant on land that you occupy if it has been planted in breach of the above rules and you are directed to do so by an authorised person.

Habitats

Disturbed forest, scrubland, fernland, forest and riparian margins, floodplains, moist habitats.

Dispersal

Vegetative spread from stolons, dispersed by soil movement.

Impact on environment

Forms dense mats, smothering native vegetation and preventing native regeneration in disturbed bush, scrubland, fernland and forest margins.

Control

Site Management

Follow up treated areas 3 times per year. Encourage natural regeneration of native plants or replant treated areas where possible after 2-3 treatments to establish dense ground cover and minimise reinvasion.

Recommended approaches

Physical control

Method: Dig out or pull out.

Plant parts requiring disposal: All parts.

Disposal options: Compost in a composting weed bag or remove to greenwaste or landfill.

Biocontrol

Biocontrol is currently not available for this species.

Community agrichemical control recommendations

Basic Growsafe certified: For small infestations - foliar spray with 0.5g metsulfuron-methyl per 1L of water.

Certified Handler/Experienced agrichemical user: For medium to large infestations -
foliar spray with 5g metsulfuron-methyl per 10L of water and 20ml penetrant.