Weeds pose a serious risk for primary producers as they can impact on market access and agricultural production.

In 2006/07, each Western Australian agricultural business spent an average of $29 376 ($341 million total) on weed control (Australian Bureau of Statistics).

Weed control is a shared responsibility between landholders, grower groups, biosecurity groups and the Department of Primary Industries and Regional Development.

To protect WA’s agriculture, the department:

  • works with landholders, grower groups, community groups and biosecurity groups
  • regulates weeds under the Biosecurity and Agriculture Management Act 2007
  • provides a weed identification service
  • provides a predictive simulation tool called weed seed wizard
  • provides information on weed control, crop weeds, regulated/declared plants and herbicides
  • contributes to social science through weedwatcher.

For advice on weeds search our website, the Western Australian Organism List or contact our Pest and Disease Information Service (PaDIS).

For diagnostic services, please contact our Diagnostic Laboratory Services.


  • Bathurst burr (Xanthium spinosum) is a declared pest in Western Australia (WA).

  • Horehound (Marrubium vulgare) is a weed in Western Australia (WA).

  • Mexican poppy is the common name given to two weeds: Argemone mexicana and Argemone ochroleuca. Both species are poisonous.

  • Heliotrope (Heliotropium europaeum) is a common summer weed in the southwest of Western Australia (WA).

  • Artichoke thistle, cardoon (Cynara cardunculus) is an uncommon weed in Western Australia (WA).

  • Thornapples, common thornapple (Datura stramonium), fierce thornapple (Datura ferox), Leichhardt’s or Mexican thornapple (Datura leichhardtii),

  • Glaucous star thistle (Carthamus leucocaulos) is an uncommon weed in Western Australia (WA). This article describes the nature of the plant.

  • Water hyacinth, floating water hyacinth, (Eichhornia crassipes) is a declared pest in Western Australia (WA).

  • In-crop weed competition causes losses costing around $1 billion per annum for Western Australia.

  • In an integrated weed management program, control of weeds should occur in the fallow, pre-sowing, early post-emergent and in pasture phases.

Filter by search

Filter by topic