General description

Evergreen perennial with woody rhizomes. Leaves are < 40 cm long, erect and often in a flattened fan. Flowers are blue and borne in clusters of 5-7. Capsules are dehiscent and three-sided, with dark red-brown seeds.

What you need to know

To help protect our environment:

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

Open and disturbed sites, roadsides, forest, scrubland, coastlines, herbfields, rocky and bare sites.

Seeds dispersed by water. Vegetative spread from rhizomes, dispersed by water. Human-mediated dispersal through contaminated soil on footwear and machinery.

Forms dense stands, preventing native seedling establishment. May facilitate introduced shrub, vine and grass succession in forests.

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 is currently not available for this species.

Community agrichemical control recommendations

Basic Growsafe certified
For small infestations:
Foliar spray with 3g metsulfuron-methyl plus 150ml glyphosate per 10L of water

Certified Handler/Experienced agrichemical user
For medium to large infestations:
Foliar spray with 3g metsulfuron-methyl plus 150ml glyphosate per 10L of water and 10ml penetrant

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

Similar species

Crocosmia X crocosmiiflora

Montbretia has only one prominent vein. It has orange flowers.

wild gladiolus
Gladiolus undulatus

Wild gladiolus has narrow leaves with a purple sheath at the base of the plant. It has greenish cream flowers.

RPMP status

Parkland with Significant Ecological Areas (Site-led)
Whole region (Sustained Control)
National Pest Plant Accord Species
Aristea - Main species image