Thistles are erect flowering plants that typically stand around 2 m in height, with spiny leaves and stems. Early identification during the rosette stage of growth would ensure easer control options.
The flowers are made up of many small flower heads and are purple in colour. The stem and leaves on the plant are a whitish grey due to a fairly dense covering of short hairs.
The flowers are purple in colour and made up of many little florets (tiny flowers), with spines on the stem and leaves. The stem leaves can grow up to 25 cm long and have a cobwebby texture.
The flowers can range from yellow to orange-yellow, and are surrounded by thin spiny offshoots that can grow up to 5 cm long. The leaves themselves are usually hairless, but can occasionally grow with hairs and the stems are hairless.
Isolated plants or small patches can be removed using tools such as a hoe or mattock. Vigilant II can also be used by applying it to at least 50% of the leaves of the plant.
When treating in grass pastures, ensure the pasture is slightly grazed and then after 7 days treat with Lontrel Advanced + MCPA amine by boom application.
For more extensive thistle infestations, it is recommended to use Grazon Extra at 1.4mL/1K of water as a foliar spray with a knapsack or 12 volt sprayer.
Herbicides for control of Thistles
# Note: Preferred product option in bold. * Consult label for details of growth stage and use, especially where range of rates is given.