Thistle Control in Your Lawn & Garden

There are many different types of Thistles that grow in Australia, but the two most common that are of concern in our lawns and gardens are Scotch Thistle and Common Sowthistle.

Scotch Thistle are spiny, soft-wooded plants that can grow up to 2 m high.

Leaves grow in a rosette shape. Leaves and stems are grey to white. Stems are woolly.

Root is a a large taproot that can grow 30 cm deep.

Flowers are large (4 cm across), very spiny, have purple tops, grow on large branching stems, and flower in summer and autumn.

Seeds are small, mottled brown, and have fine straw coloured hairs (up to 1 cm long) sticking out one end.

Lower leaves are fleshy and are green to blue-green. Upper leaves have toothed edges with a spiny tip.

Stems are round, hollow and have milky white sap when broken.

Common Sowthistle can grow up to 1.5 m tall. Plants grow in a rosette shape when young or regularly mowed, and becoming more branched as they mature in height.

Flowers are small (up to 1.5 cm across) and yellow.

Seeds are white and cottony, can survive for up to 8 years in ideal conditions.

Both Scotch Thistle and Common Sowthistle are spread by seed.

Scotch Thistle seeds are picked up on the clothes of people and fur/feathers of animals and are carried off, dropped and spread to other areas.

Common Sowthistle seeds are spread by wind.

Thistles can be very spiky, and can cause injury to people and pets. Both are profilic seeders, and can spread easily and take over.

Thistles can be found growing in lawns, garden beds, pastures, and disturbed road sites.

To control Thistles, and various other broadleaf weeds, growing in the lawn* spray the entire lawn with Yates Buffalo PRO Selective Bindii & Broadleaf Weed Killer Concentrate. Or, for the added benefit of feeding while killing weeds, spray with Yates Buffalo PRO Weed 'n' Feed Hose-On.

Please read all label instructions prior to every use.

*Suitable for Buffalo (except ST 26. Note, ST does not stand for shade tolerant. ST 26 is an uncommon Buffalo variety), Couch, Kikuyu, QLD Blue Couch, Bent, Fescue, Paspalum, and Ryegrass Lawns.

For control of individual plants in garden beds, use manual methods such as hoeing, making sure to remove as much of the taproot as possible.

When manual methods are no longer practical, spray Yates Zero Triple Strike Garden Weedkiller - it's glyphosate-free and kills weeds roots and all. Just be careful not to accidentally spray nearby plants or lawn, as they may be injured or killed. To avoid overspray, keep the nozzle close to the weed when spraying. Alternatively, you can apply this product with Yates Zero Weeding Brush - that way can direct the weedkiller where it is needed.

The best time to spray Thistles growing in the lawn is before they start to flower. Scotch Thistle flower in late spring and summer, and Common Thistles flower mostly in spring.

But don't wait for plants to mature - the younger the weed is, the smaller the root system will be and the easier it will be to control them. So as soon as you notice them coming up in the lawn, spray them. 

As soon as Thistles are noticed growing in the lawn or garden, either remove or spray them.

Scotch Thistles seeds are spread by being brought in on people's clothes and shoes, on pets and animals, and also on vehicles and tools. If you notice Thistles when out and about, check for seeds and make sure to wash, brush or pick off any before returning home.

Apply a 5-8 cm layer of organic mulch, such as sugarcane, to garden beds. Avoid using weedmat as this doesn't allow any organic matter, including broken down mulch, to go into and improve the soil. 

Don't mow the lawn too short. In summer, keep the lawn a little longer, around 8 cm tall. This will reduce the amount of seeds that can germinate because there will be less light, water and nutrients for them.

Grow a thick and healthy lawn with Yates Dynamic Lifter Organic Lawn Food - it gently feeds and improves the structure and moisture retention of the soil.