Spiny perennial thistle <1.6m tall. Forms a rosette in first year & a ribbed branching stem in second year. Leaves are 5-7 lobed, with short spines on the tips. Small white, pink or purple flowers on end of stems.
Pasture, roadsides, wasteland, lucerne crops, hill country, grasslands. Tolerates a wide range of climatic conditions.
Seeds dispersed by wind.
Aggressive pasture species, forming thick stands that reduce carrying capacity of land & obstruct & injure stock.
Matures later than nodding thistle, making the plant more difficult to control. Good pasture management including avoiding overgrazing will inhibit establishment.
1. Biological agents give some control.
2. Grub out scattered plants removing at least 5cm of taproot.
3. Spot spray crowns of larger plants (100ml glyphosate/10L or 120ml Tordon Gold/10L or 25ml clopyralid/10L). Do not use clopyralid in home gardens.
Gun spray large infestations (500ml Tordon Gold/100L).
4. Boom spray autumn to early winter for seedlings or small plants only (4L glyphosate/ha).
Caution: when using any herbicide or pesticide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.