Erect biennial or perennial herb <60cm tall with pungent smell. Reddish-purple stems. Young rosette <15cm in diameter. Wrinkled, divided leaves dark green on top with a downy lining. Bright yellow flowers in clusters. Downy, parachute-like seeds.
Pasture, waste places, riverbeds, open forests, swamps. Prefers light soils & high rainfall.
Numerous seeds dispersed by wind, water, animals, vehicles, clothing & hay etc. Can also spread from root or crown fragments. Cutting or grazing can convert plant into a perennial.
Aggressive invader that soon becomes dominant cover. Also toxic to stock, especially cattle & horses.
Can be left in regenerating bush & shrubland, as will disappear as light levels fall. Do not dig or pull plants, except in drought conditions, as root fragments remain & grow into perennial plants. Do not mow. Longitarsus beetle gives good control but takes 2-5 years to attain sufficient numbers. Pasture management is important; keep a vigorous dense cover to reduce infestation & avoid overgrazing especially in summer. Can be controlled by sheep; mob stocking of sheep 4 times between autumn & spring can also give good control.
1. Ensure widespread introduction of Longitarsus ragwort flea beetle.
2. Weed wipe spring - summer only (300ml glyphosate + 2ml penetrant/1L or 1g metsulfuron + 1ml penetrant/1L or 500ml Tordon Gold/1L).
3. Spray rosette plants winter - spring only, before stem formed (2,4-D ethylhexyl ester 2-4L/ha in 100-200L water or hand gun 50ml/10L water).
4. For mature plants spray until flowering (100ml glyphosate/10L or 1g metsulfuron/10L or 50ml clopyralid/10L (Do not use clopyralid in home gardens)).
Caution: when using any herbicide or pesticide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.