How to apply herbicides

Depending on the species of weed and the product used to treat, there are a number of different ways in which each herbicide can be applied to the target weed.


Woody weeds are vigorous and hardy. Their persistent nature means it is essential to use a programmed approach over three or more seasons to control them. Different woody weed species often require different herbicides and application techniques for long-term control, so always read the label before undertaking any herbicide treatment.

Cut Stump application

Cut Stump application is the preferred method for saplings that are too small to be stem injected. Cut stems as close to the ground as practical, no higher than 10–15 cm from ground level. Thoroughly spray the herbicide mixture immediately after the cut is made; this is necessary because the plant can seal the cut quickly, thus barring the chemical from penetrating into the sap stream.

Hand application of granules

This method is ideal for controlling scattered weeds along fence lines or in isolated patches. Apply granules or pellets to the soil prior to spring or summer rains. It is essential that the root area of the woody weed is evenly treated with the pellets or granules.

Basal Bark application

Use this method to treat saplings and regrowth less than 5 cm in basal diameter. The herbicide is applied mixed with diesel to assist penetration through the bark. Always refer to the product label for details. Make sure you thoroughly treat the whole circumference of each stem from ground level to a height of 30 cm.

New ThinLine™ Application technique saves time and diesel

A new technique to apply Access + diesel has recently been approved for use called ThinLine Application. The same equipment is used for both Basal Bark and ThinLine techniques – the difference is the height of the stem that needs to be treated and the dilution rate.

Foliar Spray application

This method normally refers to high volume application using a handgun to treat the foliage of the plant. It is recommended to use a number 5 to 8 tip in your handgun and calibrate your pump pressure to ensure adequate penetration of dense bushes.

Stem Injection application

This method is used to treat standing timber or regrowth with a stem diameter greater than 5 cm. Make horizontal cuts with a narrow-bladed axe 5–7 cm wide through the bark of the woody weed into the sap stream at waist height. Space these at 10–13 cm around the circumference of the plant. Leave the axe in the cut and immediately (within three seconds) apply the herbicide down the axe blade to ensure the full dose enters the sap stream.

Tips on effectively using herbicides

Avoiding off target plant damage

Its important to be aware of the surrounding environment when spraying woody weeds because if you are not careful you might inadvertently cause damage to other vegetation in the area or allow chemicals to enter a waterway.

Spraying poisonous weeds around livestock

Most of the time livestock will avoid poisonous weeds on your property, however spraying those weeds with herbicide can sometimes make them more palatable, meaning that your livestock may eat the weeds which could cause lasting damage.

Spot spraying with Grazon™ Extra

It's important to ensure you read the label before undertaking any spray application. When applying Grazon Extra as a foliar spray, ensure you get an even coverage of the entire plant, spraying to the point of runoff

Spot spraying with a larger mixing tank

Before undertaking any herbicide application, its important to ensure you check the label for the correct mixing and application rates, as well as the right protective gear. Ensure you get full and even coverage across the entire plant, spraying to the point of runoff.