Plectranthus

General description

Trailing or straggling herb or shrub. Stems are hairy. Leaves are shiny and serrated, with green tops and purple undersides. Flowers are white, flecked with purple inside the lower lip, and held in raceme-like inflorescences < 30 cm long.

What you need to know

To help protect our environment:

• You must not breed, distribute, release or sell plectranthus. As plectranthus 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 plectranthus 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 plectranthus 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

Coastal areas, forest, forest margins, open areas, banks, clay, pasture, roadsides, shrubland, wasteland.

Dispersal

Vegetative spread from runners. Human-mediated dispersal through dumping of garden waste and movement of contaminated soil.

Impact on environment

Forms dense mats, suppressing native seedling regeneration.

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.

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

No qualifications:

For small infestations: Cut stump and paste freshly cut base of stems with double strength glyphosate gel. Cut stems will resprout. Or foliar spray with 10ml glyphosate green per 1L of water.

Basic Growsafe certified:

For small infestations: Cut stump and spray freshly cut base with 250ml glyphosate green per 1L of water. Cut stems will resprout.

Certified Handler/Experienced agrichemical user:

For medium to large infestations: Foliar spray with 100ml glyphosate green per 10L of water and 20ml penetrant.