Nodding thistle

Nodding thistle is an invasive weed but thankfully has not yet spread to all suitable habitats in the the Southland region. It is easily recognisable due to its large crimson heads that drops or “nods” when mature.

What is it?

Nodding thistle is a large annual or biennial thistle that grows from an over-wintering rosette

A native of Europe, Asia and North-West Africa, nodding thistle was first recorded in New Zealand in 1889. It is believed to have been imported as a contaminant in seed.

Its distinguishing features are reddish-purple flower-heads which droop downwards. The flower-heads droop long before they mature and their stems, just below the flower-heads, are leafless.


What is the problem?

Nodding thistle is a serious threat to agricultural production. It grows in dense patches achieving almost total ground cover, and is not readily grazed due to its spiny foliage. This can seriously reduce stock carrying capacity. At maturity, the spiny heads contribute to vegetable fault in wool.

How to control it

Nodding thistle can be controlled via the following methods:

Control methodExample

Competition

Maintain a dense pasture in autumn to out-compete and prevent the thistles germinating.

Herbicide control

Spraying.

Biological control

Insects such as the green thistle beetle and californian thistle stem miner reduce the vigour of nodding thistle. Find out more about biocontrol options.

For details on control methods, see our factsheet on nodding thistle.

Classification

Nodding thistle is a Containment Plant throughout the Southland region. It has established in Southland and its distribution and abundance has reached such an extent that eradication is not cost effective, or indeed possible. Our aim is to prevent it from spreading onto neighbouring properties.

Rules

Land occupiers within the Southland region must destroy all nodding thistles, before seeding, on land they occupy. For a full explanation of the rules for nodding thistle see the Regional Pest Management Strategy.

Monitoring

Environment Southland monitors Southland properties for nodding thistle each year. We also respond to complaints received about nodding thistle from neighbouring landowners.

Page reviewed: 09 May 2016 10:49am