Form: herbaceous — perennial
Status: present in WA
Orignating in Europe, Ragwort is a major pasture weed in New Zealand, Tasmania and Victoria. In WA it is currently confined to one property, but pastures in the high rainfall districts (more than 750 millimetres) are at risk from this weed.
Ragwort is normally a biennial or perennial upright plant 0.6-1 metres tall.
Stems: each plant has numerous separate stems; each rigid branched stem is greenish-purple in colour.
Leaves: deeply lobed, ragged in appearance, dark green on top and lighter underneath.
Flowers: daisy-like, in bright yellow heads about one centimetre across. Flowers from October to March.
Seeds: light brown, about two millimetres long by 0.5 millimetres in diameter and attached to a pappus of feathery hairs. Most seeds germinate almost immediately, but some may remain viable in the soil for many years.
Mature plants have a crown just beneath the soil surface, from which numerous fleshy roots are produced. Ragwort reproduces from seed, from root fragments and from the crown of the plant, which persists from season to season.
Online weed identification training
Login or set up a new account on DPIRDs online training site to access:
- a training course on how to identify ragwort and report it.
- training material that you can use to teach community groups how to identify ragwort.
Agricultural and economic impact
Ragwort competes strongly with more desirable pasture species and can be a very difficult plant to control. Ragwort is poisonous to stock, especially cattle and horses, but animals generally avoid it unless they are hungry. Cows forced to eat ragwort produce tainted milk.
Declared pest category
The Western Australian Organism List (WAOL) contains information on the area(s) in which this pest is declared and the control and keeping categories to which it has been assigned in Western Australia (WA). Search for ragwort in the WAOL using the scientific name Senecio jacobaea.
Requirements for land owners/occupiers and other persons
Requirements for land owners/occupiers and other persons if this pest is found can be sourced through the declared plant requirements link.
Search > detect > report
Pest and Disease Information Service (PaDIS)
Detectability: hard to find. Mature ragwort plants are quite distinct with their abundance of yellow flowers but could easily be confused with other yellow daisy-flowered species, including native Senecio species and Dittrichia viscosa.
Who should look for it: there is currently only one known infestation near Walpole; owners/managers of the known affected property, adjacent properties and any properties that have links with the affected property should be aware of this weed.
When to find it: ragwort is most likely to be found at flowering, which is from December to March, plants can take several years before they flower.
Where to find it: humid temperate regions with annual rainfall greater than 750 millimetres.
Control methods for this declared plant can be found through the ragwort control link.