Hawkweed

General description

Small perennial broadleaf herbs with milky sap. Stoloniferous, with an extensive underground root system. Leaves are narrow and in a basal rosette or along the stem. Flowerheads are dandelion-like and yellow/orange in spring – summer. Seeds are 4-8 mm long and have fluffy, dirty-white hairs.

What you need to know

To help protect our environment:

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

Tussock, grasslands, scrubland, forest, roadsides, riparian margins.

Dispersal

Seeds dispersed by wind and attachment to clothing and animal pelts. Vegetative spread in some species from rhizomes and stolons. Human-mediated dispersal through dumping of garden waste.

Impact on environment

Reduces feed plant cover and pasture productivity. Potential to exclude native plant species from grasslands, scrubland and riparian 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.

Plant parts requiring disposal: Seeds, rhizomes and stolons.

Disposal options: Remove to greenwaste or landfill if practical.

Biocontrol

Biocontrol is currently not available for this species.

Community agrichemical control recommendations

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

For infestations amongst desirable species: Foliar spray with 25ml clopyralid per 10L of water and 20ml penetrant (not for use in home gardens).