Cut thistle to ground level

Cut thistle to ground level with hand pruners, loppers or a string trimmer. Cutting alone will not eliminate thistle but it is an important first step.

Do it at the right time of year

If you are trying to prevent the thistle from spreading then it is important to not let the thistle produce seeds. Cut thistle before it produces seed heads. This may need to be done repeatedly throughout the year.

Pull thistle out from the roots

Small and young thistle plants can be pulled out from the roots. This is easiest when the soil is soft and wet.

Be careful of spreading seeds

If the thistle you are cutting has seed heads or mature flower heads it must be disposed of properly. The seed heads will continue to ripen even after the plant is cut. It is very important to take the plant to a disposal facility or bag it in a plastic bag so further spreading of seeds does not occur.

Mowing

If the area is flat enough to mow this is an effective alternative. Thistle grows very quickly so the area will need to be mowed weekly in order for it to be effective.

Herbicide

Be sure to read and follow all the instructions on your herbicide label. It is best to have a licensed professional apply herbicide. Natural methods such as vinegar will not kill thistle. The only effective thistle killer is herbicide.

Covering

Cut the thistle to ground level. Cover the area in an opaque tarp or sheet of plastic. It is very important no light can pass through the covering. This will prevent the thistle from photosynthesizing and the plants and root system will eventually die after one year or more of being covered.

Expert Help:

We care intensely about the success of each project. Contact us for a free in-person quote in Victoria, BC.