When we talk about the importance of conducting biosecurity practices on-farm, this is not only to minimise the introduction of pests and pathogens, but weeds too.

Operating under a ‘clean in, clean out’ mantra is valuable when it comes to minimising the introduction of weed seeds onto your property. This means checking machinery, vehicle tyres, footwear and clothing for weed seeds upon entry to your property and ensuring no weed seeds have been picked up on your property before machinery, vehicles and people leave.

Are you aware of your obligations around weed management in South Australia? As a land holder you have a legal responsibility to manage declared plants. These are plants regulated under the Natural Resources Management (NRM) Act 2004 as significant weed threats to our State’s primary production industries, natural environments and public safety. There are more than 137 declared plants in South Australia. Find out which plants are declared by referring to The Declared Plants of South Australia poster.

Plants may be declared under various sections of the NRM Act, relating to:

  • Movement – some declared plants must not be moved on a public road (e.g., as a cutting, seed or potted specimen). Inadvertent movement of the plant on animals, soil, vehicles, machinery or produce may also be illegal.
  • Sale – most declared plants must not be sold at any outlet including nurseries, pet shops and market stalls. Sale of any animal, soil, vehicle, machinery or produce contaminated with these plants is also illegal.
  • Notification – the presence and locations of some declared plants on your own land must be reported to the NRM group Biosecurity Unit or your regional NRM office Natural Resources Centre.
  • Control – as a landowner, you are required to take action to destroy or control many declared plant species present on your property, regardless of whether it is used as a business, residence or for other purposes. NRM authorities also control certain declared plants on road reserves and can recover costs of control from the adjoining landowners.

South Australia’s eight regional NRM Boards coordinate and enforce local and regional control programs for declared plants. Declarations of plants (including local requirements for control) vary between and within NRM regions. Priority species for regional control programs also vary depending on the threats a weed poses in particular localities, whether it is a new invader or widespread, ease of control and time of year.

Get advice on which declarations are relevant for you and your property, and how to manage your weed problems by contacting your local NRM Board.

The Declared Plants of South Australia poster provided five tips for successful weed control:

  1. Prevention is cheap – insist that vehicles, machinery, livestock and produce coming onto your property do not carry weed seeds. Report sales of declared plants. Pay particular attention to Alert Weeds, which have yet to become established in South Australia.
  2. Find weeds early – get to know plants on your property and quickly identify and deal with new threats.
  3. Watch your spread – take measures to contain weed infestations and prevent further seed dispersal across your property.
  4. Plan your controls – obtain information about managing your target weed. Map the area you need to treat. Treat weeds when they are young. Use the recommended control method. Use selective herbicides where possible. Minimise damage to non-weeds. Establish and promote competing vegetation.
  5. Persistence, persistence – continue follow-up treatments for as many years as necessary. Some plants may have been missed, some may have survived treatment and new seedlings may emerge.