Basal bark treatment

The basal bark treatment is suitable for trees or shrubs that are actively growing and not stressed. It is not suitable for plants with thick, papery bark.

Video courtesy of Northland Regional Council

Before you start ensure:

  • you have the right safety equipment
  • the weather conditions are good, that is, a sunny day
  • all pets and children are safely away from the treatment area
  • you have read and heeded all of the herbicide labels and equipment manuals

The equipment you will need is:

  • hat, safety eyewear, long-sleeved shirt, long pants, covered footwear
  • chemical resistant gloves, face shield, mask, impervious apron
  • herbicide, measuring container, small paint brush and a sealable container

Herbicide mixing

Estimate the amount of mixture you will need - be conservative. It is easier to mix up more herbicide than it is to dispose of excess mixture.

Measure out the required amount of kerosene and add it to a container, then measure out the required amount of herbicide and add it to the container. (The quantities are available on the APVMA off label permit.)

Seal all containers and agitate the mixture with a paint brush.

Paint the stem

Starting at the base of each stem, paint all the way around the stem to a minimum height of 30 centimetres.

Ensure the treated area is not disturbed for 24 hours to allow herbicide uptake.

Depending on the species, this technique can take up to two months to show results so you will need to be patient.

Clean up

Step one

Any left over mixture must be disposed of in a pit that has been prepared with lime or wood ash. The pit must be situated at least 50 metres away from watercourses.

Dig a hole. The size of the hole depends on the amount of herbicide left over and the equipment rinsings but must be a minimum of 15 centimetres deep.

Place some lime into the hole and mix with the soil. Then cover the bottom of the hole with one centimetre of lime.

Step two

All equipment and empty containers should be triple rinsed to remove all traces of herbicide. Pour any left over herbicide and all rinsings from equipment into the hole. Cover the hole with at least 15 centimetres of soil.

Finally, cover the area to prevent children and pets gaining access. All herbicides and other hazardous materials should be stored in their original containers out of the reach of children and pets.

More information

For more information send an email to the Invasive species team.