Hawkweed

Hawkweed is a group of perennial herbs that form rosettes with thick underground root systems. They have a milky sap and flowers similar to dandelions.

Description

• Leaves are narrow and in a basal rosette or along the stem.

• Stems are thin and produce a milky sap.

• Stoloniferous, with an extensive underground root system.

• Flowerheads are dandelion-like and yellow/orange in spring – summer.

• Seeds are 4-8mm long and have fluffy, dirty-white hairs.

• Dispersed by wind and attachment to clothing and animal pelts.

• Vegetative spread via rhizomes and stolons.

• Habitats include tussock, grasslands, scrubland, forest, roadsides, and riparian margins.

What you need to know

Hawkweed reduces feed plant cover and pasture productivity. It has the potential to exclude native plant species from grasslands, scrubland, and riparian margins.

Management approach

Hawkweed is declared an unwanted organism by the Ministry for Primary Industries (MPI) because it is capable of causing harm to the natural environment, physical resources or human health in Aotearoa/New Zealand.

These species pose a high risk to our environment, economy, recreation, and cultural values.

Rules

Any species declared a pest cannot be sold or be in a place where plants are being sold. Pest plants cannot be propagated, bred, multiplied, communicated, released, caused to be released, or otherwise spread.

To help protect our environment:

Consider removing this invasive species from your property and consult your local council for appropriate disposal. Consider lower-risk alternatives for your garden, such as native plants.

Control

Site management

Follow up treated areas three 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.

Physical control

Dig out

Plant parts requiring disposal: all parts

Contact your local council for appropriate disposal locations

Chemical control

Foliar spray with 0.5g metsulfuron-methyl plus 3ml penetrant per 1L of water.

Foliar spray with 6ml picloram/triclopyr mix plus 1ml non-ionic surfactant per 1L of water.

Foliar spray with 12.5ml clopyralid per 1L of water.

Spread pellets containing picloram (20g/kg) underneath the plant to a maximum of 55g per square metre.

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