Weed control

Weeds in New Zealand are usually introduces plants that have escaped a garden setting and are now wild. Invasive weeds are destroying our native plant communities and transforming the natural landscapes that make New Zealand unique.

We need to work together to remove the weeds from private and public land, as the problem will get worse if there is no action.

As weeds spread across our landscapes they:

• Create a fire risk.
• Can cause acidification of soils which leads to the depletion of some minerals in the soils.
• Use more water, so runoff is decreased which affects streams and associated fauna in the water catchment.
• Provide habitat for exotic pest plants, animals and diseases.
• The fast growth rates of for example wilding pines allow them to out compete and suppress low-stature native vegetation.

We are guided by the Regional Pest Management Plan 2018, the Biosecurity Operational Plan 2018-2028 and the Biosecurity Act 1993.

Common types of weeds
Trees and shrubs (woody plants)

Weeds that are trees or shrubs grow over or replace other plants.
Weed trees include holly, tree privet, sycamore, wattles, willows, and wilding pines.
Examples of weed shrubs are barberry, boneseed, broom, buddleia, cotoneaster, gorse, heather and privet.

Herbs (non-woody plants)

Herbs or perennials are non-woody plants. They can grow over small plants, crowding and preventing the regeneration of native seedlings.
Examples include Chilean rhubarb, montbretia, Mexican daisy, pampas, purple loosestrife and wild ginger

Vines

Vines climb and scramble, smothering trees and forest canopies.
Examples include banana passionfruit, bomarea, Chilean flame creeper, climbing spindleberry, ivy, Japanese honeysuckle, old man’s beard, mothplant and wonga wonga vine.

Aquatic

Weeds can grow in aquatic habitats, eg oxygen weed that grows in lakes or Eel grass (Vallisneria australis).

Marine

Weeds can also grow in marine habitats.

Or other creatures like the invasive Mediterranean fanworm (Sabella spallanzanii) which look like plants but are actually animals.

Further information

• Weedbusters website.
• Plant Conservation Network website.
• iNaturalistNZ website where you can get help on identifying weeds.
• Department of Conservation – Weeds.
• Marlborough District Council Biosecurity A to Z of Pests.
• Regional Pest Management Plan 2018.
• Biosecurity Operational Plan 2018-2028.