Weed treatment timing

In order to get the best results when treating woody weeds with herbicide, there are a number of variables that need to be considered:

  • The geographical area which you are in
  • The species of weed that you are trying to treat
  • Climate conditions in your area
  • The treatment method used.

This is because the weed needs to be treated when the plant is actively growing to allow maximum uptake of the herbicide into the root system, which is the only sure way to ensure you kill the entire weed.

If the plant is under stress due to environmental factors like lack or rainfall, or is not in its optimal growth period, then there is no guarantee that the chemical application will be effective.

Visit our Weed Identification page for details on what to look for when the plant is actively growing.

When should I treat woody weeds?

The table below indicates the timing to treat different species of weeds in a Northern or Southern region, and the recommended products to use to achieve the best result.

TORDON GRANULES
Weed Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug
Blackberry
Fireweed North NSW/QLD
Fireweed North NSW
St John's wort
Sweet briar
Gorse
Lantana/associated weeds
Rubber vine
Eucalypt regrowth/wattle
STARANE ADVANCED HERBICIDE
Weed Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug
Lantana
Prickly acacia
Wattle regrowth

Starane™Advanced and Grazon™Extra herbicides are best applied to weeds by a foliar spray. Treatments must only be carried out when plants are in full leaf and flowering, which should be six to eight weeks after rainfall.

ACCESS HERBICIDE
Weed Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug
Deciduous plants
Non-deciduous plants

Access™ Herbicide is best applied using ThinLine™ Application technique, which is a variation of basal bark application.

STINGER HERBICIDE
Weed Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug
Blackberry

Stinger™ Herbicide comes in granular form which must be mixed with a wetting agent to help the herbicide penetrate into the plant.

TORDON GRANULES
Weed Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug
Sweet briar
Blackberry
Africa boxthorn
Lime bush
Eucalypt regrowth
Ragwort
KEY
Best time to spray/treat
Can spray/treat if conditions are suitable
Do not spray/treat

Tordon™ Granules come in a granular form that are applied directly to the immediate area around the weed and to the weed itself.

For further information on the best way to apply herbicide to the target weed visit: