What does it look like?
Cotton thistle is a prickly biennial thistle standing up to 3m tall and 1.5m wide. It has spiny grey, velvety leaves and stems covered with white cottony hairs. The flowers are dark pink, lavender or purple, globe shaped and 2.5-6cm in diameter.
Why is it a problem?
Cotton thistle forms large stands which are impenetrable to stock and so pasture is displaced. Plants are drought resistant and can spread rapidly as seeds are primarily dispersed by wind. Seed heads can become entangled in wool and fibre, devaluing fleeces and injuring those handling stock and fleece.
Control methods
Contact us at biosecurity@hbrc.govt.nz if you believe you have sighted Cotton Thistle on your property for best advice on control methods.
More information
Cotton Thistle is a Progressive Containment pest under the Hawke’s Bay Regional Council Regional Pest Management Plan 2018 – 2038 and is subject to Plan Rule 5.
Related links
Notify Council
If you think you've found this pest, please get in touch with our Biosecurity Team at biosecurity@hbrc.govt.nz or call us on 0800 108 838.
Management Programme
Progressive Containment Programme
To contain or reduce the geographic distribution of the subject, or an organism being spread by the subject, to an area over time.
Rules
Rule 5 - Cotton Thistle
Except where an occupier of land has entered into a Written Management Agreement approved by Hawke’s Bay Regional Council, an occupier of land shall destroy all [NAME] plants on their land.
