- Your Council
- Living in Northland
- For Schools
- Civil Defence
Ragwort is a member of the daisy family. It is an erect, annual to perennial herb and usually grows to 45-70cm tall, but can reach 1.6 metres. It has reddish-purple stems and wrinkled, divided leaves, which are dark green on top with a downy lining. Leaves appear in a rosette that grows into a dense cluster. Its flowers are bright yellow, and appear in clusters. Downy (fluffy), parachute-like seeds are present.
Ragwort prefers areas of open space with some area of bare ground for seeds to germinate on, particularly in high rainfall areas. It will invade open forests, riverbeds, swamps, pastures and coastal areas. It also tolerates a wide range of environmental conditions, except for shade. Especially abundant in areas of higher rainfall. A well-known pest on dairy farms. Densities of this species have steadily declined in Northland since the introduction of a boiological control, the flea beetle. As such, this species is no longer a significant threat on most properties.
An aggressive, prolific flowering plant that colonises exposed areas, i.e. paddocks. Matures quickly, may reduce the productivity of the land and may out-compete native plant seedlings.
The ragwort flea beetle (Longitarsus jacobaeae) has established well throughout Norhtland and many areas, that have not been regularly sprayed, have very low numbers of ragwort now. Information on this beetle and how to find it on your ragwort can be found at Landcare Research
The best advice for long term control of ragwort is to not to spray or control ragwort at all. Landowners are encouraged to wait for the numbers of flea beetle and ragwort to be in balance, this can take 7 - 10 years, then there will be a few ragwort plants around to support an ongoing population of flea beetles.
If you feel you must use some control, winter (July/August) is the safest time to control ragwort as larvae are pupating. However be aware that the less food available, the less beetles will survive for the following season.