Blackberry (wild aggregates)

General description

Prickly, scrambling, woody perennial shrub. Rhizomes are dense and layered. Stems are < 8 m long, arching and entangling, with large backwards-pointing thorns. Leaves are compound and palmate, with three to five oval, toothed leaflets, and prickly stalks and midribs.

Flowers are white/pink and are borne in clusters November – April. Fruit is aggregated and red, ripening to black.

What you need to know

To help protect our environment:

• You must not breed, distribute, release or sell blackberry (wild aggregates) within the Auckland region.
• You must not plant blackberry (wild aggregates) 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 blackberry (wild aggregates) 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

Scrub, riparian and forest margins, shrublands, fernland, riverbeds, wetlands, sand dunes, roadsides, wasteland, pastures, orchards, plantations.

Dispersal

Seeds dispersed by birds, other animals, water and soil movement. Vegetative spread from rhizomes.

Impact on environment

Displaces and smothers native vegetation. Reduces pasture production and capacity and injures stock. Can dominate forestry plantations, impeding access and reducing overall yield. Host for blackberry rust Phragmidium violaceum.

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: Remove to greenwaste or landfill if practical.

Biocontrol

Check for presence of agents:

• Blackberry rust (Phragmidium violaceum) - Self-introduced.

For more information about how biocontrol works, see What is biocontrol?

Community agrichemical control recommendations

No qualifications: Cut stump and paste freshly cut base of stems with metsulfuron gel.

Basic Growsafe certified: Foliar spray with 5g metsulfuron-methyl per 10L of water.

Certified Handler/Experienced agrichemical user: Foliar spray with 5g metsulfuron-methyl per 10L of water and 20ml penetrant.

Safety notes

Plant has thorns.