Thistles (Scotch and nodding) control

Access all the information needed for control of this noxious weed, including weed identification, herbicide application and spray timings.


Description

Thistles description

Thistles identificationn

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.

SCOTCH THISTLE

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.

SPEAR THISTLE

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.

SAFFRON THISTLE

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.

Thistle control

Controlling thistles

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, wiping the applicator along the middle of each leaf.

When treating in grass pastures, ensure the pasture is slightly grazed and then after seven days treat with Lontrel Advanced + MCPA amine by boom application.

For more extensive thistle infestations, it is recommended to use Grazon Extra at 150 mL per 100 L of water (1.5 mL per 1 L) as a foliar spray with a knapsack or 12 volt sprayer.

Herbicides for control of thistles

Product#Method of applicationRate*State
Lontrel® Advanced Herbicide Boom application 25 or 35 mL/ha + 1 or 1.5 L/ha MCPA amine (500 g/L) NSW, Qld, SA, Tas, Vic
Lontrel® Advanced Herbicide Boom application 1 L/ha All
Hotshot® Herbicide Foliar spray 500 mL/100 L of water All
Lontrel® Advanced Herbicide Foliar spray 125 mL/100 L of water NSW, Qld, SA, Tas, Vic
Grazon® Extra Herbicide Foliar spray 150 mL/100 L of water All
Vigilant® II Herbicide Leaf wiping Neat: 50% leaf area All

# Note: Preferred product option in bold.  * Consult label for details of growth stage and use, especially where range of rates is given.

Treatment timing

Timing for thistle control

Always treat actively growing plants – DO NOT treat under dry conditions.

ProductSepOctNovDecJanFebMarAprMayJunJulAug
Grazon® Extra Herbicide
Hotshot® Herbicide
Lontrel® Advanced Herbicide
Vigilant® II Herbicide
Key: Best time to spray/treat Can spray/treat if conditions are suitable Do not spray/treat
Woody Weed Specialist