Controlling Nodding Thistle
Submitted by New England Weeds Aurthority
Nodding thistle (Carduus nutans) was introduced into Australia through imported pasture seed back in the1940’s. Like most of the thistles, they are very spiny, establish in dense patches and are not palatable tostock or wildlife. It is estimated that nodding thistles now infest about 1 million hectares of the NSW tablelands.
Nodding thistles have very distinctive flowers which droop at right angles to the stem, that’s where they get the name ‘nodding thistle’ or ‘nodders’. Nodding thistles have a long flowering season usually from November to April. They produces huge amounts of long lasting seed and can germinate and grow at any time of the year providing conditions are suitable – all of which make it a very aggressive competitor in pastures and grasslands. These attributes also make it difficult to control, particularly in our more fertile soils.
Nodding thistles require a period of chilling (vernalisation) which the New England winter provides and as a result they have established extensively in the region. Control methods include physical removal, herbicides, grazing management and pasture improvement. Given the longevity of the seed a management plan will need to extend over a number of years. All landholders have a General Biosecurity Duty under the Biosecurity Act 2015 to control Nodding thistle on their land so as to prevent their spread to neighbouring properties via wind blown seed. Management obligation for this and other regional priority weeds can be found at our website newa.com.au under the tab ‘Weed Control Management Plans’.
For help with weed identification and management please contact any of our Biosecurity Officers
(Weeds) on 67703602, call into our office at 2/129 Rusden St Armidale or visit www.newa.com.au.