How to manage weeds

Chemical control

Chemical weed control uses herbicides and other chemicals to control weeds in specific situations, which are specified on the herbicide label. 

Herbicides must be used according to the directions for use on the Australia Pesticides and Veterinarian Medicines Authority registered label. 

Go to the Australian Pesticides and Veterinary Medicines Authority (APVMA) website for more information.

There are a variety of techniques and equipment available to apply herbicides. 

The method chosen is determined by the type of weed and its growth, size of the infestation, access, resources available, and personal preference.

Foliar application

Herbicide is mixed with water and often a wetting agent and applied to the leaves of plants using either hand held spray packs or larger systems mounted on machinery.

This is an effective way to kill grasses and smaller woody weeds.

Foliar spraying of athel pine
Foliar spraying of athel pine.

Cut stump treatments

Larger weeds are physically cut as close to the ground as is possible using brush cutters, loppers, or chainsaws and herbicide is applied immediately to the freshly cut surfaces of stumps or grasses. 

This method helps to control the tree root system, and is especially useful in species that spread via suckers by preventing sprouting and regrowth.

Chemical application to cut mimosa stump
Chemical application to cut mimosa stump.

Rope wick application

A wick or rope is soaked in herbicide and used to wipe or brush the chemical over the weed. This can be from a reservoir attached to a handle or it can be pumped to the wick using 12-volt equipment. 

This is a useful method when killing a certain weed to avoid damaging surrounding plants.

Soil applied spot concentrate

Herbicide is applied directly to the soil beneath the weed and is taken up by the roots or the newly emerging shoots.

Basal barking

Oil soluble herbicide is mixed with diesel and sprayed around the full circumference of the trunk or stem of the weed. The diesel helps the herbicide to move through the bark and allows it to enter underground storage organs within the weed to slowly kill it. 

This is an effective way to treat saplings, regrowth and multi-stemmed shrubs and trees.

Basal bark spraying of athel pine
Basal bark spraying of athel pine

Stem injection

A hole is drilled or cut through the bark of woody weeds and trees, and into the vulnerable sapwood tissue, and herbicide is immediately placed into the hole. The natural transportation systems within the weed then move the chemical through its tissues.

Demonstration of stem injection technique
Demonstration of stem injection technique.

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Last updated: 27 June 2017