Carduus nutans

Nodding thistle

Also known as:

Musk thistle

Family: Asteraceae

Origin: Eurasia

Nodding Thistle in flower with bumblebee.
A thistle that can survive for up to two years. Covered in sharp spikes the leaves are not eaten by stock and plants can invade farm paddocks.

Regional Pest Management Plan (RPMP) status

  • Whole region — Sustained control
  • Hauraki Gulf Controlled Area Notice pest

View more about the RPMP statuses

General description

Annual or biennial thistle. Taproot is long and fleshy. Leaves are long, narrow and spiny. Flowers are drooping, purple and borne on erect flower stems in spring-summer. Seeds are attached to pappus.

What you need to know

To help protect our environment:

  • You must not breed, distribute, release or sell nodding thistle within the Auckland region.
  • You must not plant nodding thistle within the Auckland region.
  • You must destroy all nodding thistle plants on land that you occupy.

Habitats

Pasture, wasteland, roadsides.

Dispersal

Seeds dispersed by wind, soil movement. Human-mediated dispersal through movement of contaminated soil, machinery and agricultural materials.

Impact on environment

Suppresses valued pasture plants and impedes livestock access to forage. Allelopathic.

Control

Site Management

Maintaining good pasture cover can prevent establishment or suppress an infestation. Prevent overgrazing especially in summer. Other herbicides are available for selective use in pasture.

Recommended approaches

Physical control

Method: Dig or grub out at least the first 5cm of taproot.

Plant parts requiring disposal: Seeds.

Disposal options: Remove to greenwaste or landfill if practical.

Biocontrol

Check for the presence of agents:

  • Nodding thistle receptacle weevil (Rhinocyllus conicus)
  • Nodding thistle gall fly (Urophora solstitalis)
  • Nodding thistle crown weevil (Trichosirocalus horridus).

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

Community agrichemical control recommendations

No qualifications: Foliar spray with 100ml glyphosate green per 10L of water.

Certified Handler/Experienced agrichemical user: Foliar spray with 100ml glyphosate green per 10L of water and 20ml penetrant.

Safety notes

Plant has spines.

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

Nodding Thistle plant in grass paddock.
Flowers are formed at the end of branches, and are large and pink/ purple in colour. A favourite of bees and butterflies, insects are the main pollinators of the flowers.
Nodding Thistle plants in a farm paddock.
Plants have a large tap root and are hard to pull out. Grubbing plants before they seed is a good way to control the plants.
Immature Nodding Thistle in a paddock.
Seeds are attached to white fluff and are carried in the wind. Seeds can remain viable for a long time and come up on pasture long after adult plants are removed.
Nodding Thistle plant coming into flower.
A hardy plant that can grow in many conditions but thrives in pasture, wastelands and roadsides. Because the spiky leaves can hurt noses on livestock it can prevent them eating grass close to the thistle reducing their available food.
Photo credit: Jeremy Rolfe
Nodding Thistle close up of flower and flower buds.
Each flower can result in hundreds of seeds which can be carried for kilometres on the wind. If any mature seed heads are caught up when harvesting hay, plants can be moved around a farm.
Photo credit: Jeremy Rolfe
Mature Nodding Thistle on grassy mound.
Seeds need access to soil and to germinate so prevention of overgrazing is a good way to stop seeds germinating. Herbicides can be used to control but if applied too late will still allow the plant to set seed. Manual control is best.
Photo credit: Jeremy Rolfe