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Groundsel bush (Baccharis halimifolia)

A woody shrub that invades coastal pasture, plantations, wetland edges and road corridors in south-east Queensland and northern New South Wales.

Key facts

Type: Weed, shrub.

Native to: North America.

Established in: QLD, NSW.

Best time to act: Treat in spring and summer before autumn seeding.

Identification

  • Shrub to 4 m with pale green, wedge-shaped leaves coarsely toothed near the tip.
  • Male and female plants; female plants produce masses of fluffy white seed in autumn.

Where it grows

Coastal pasture, plantations, saltmarsh edges, drains and roadsides.

Why it matters

  • Displaces pasture and native vegetation.
  • Thickets reduce access.

How it spreads

  • Wind-blown seeds travel long distances.

Control options

  • Hand pull or grub small plants.
  • Registered herbicides via foliar, basal bark or cut stump.
  • Treat before female plants seed in autumn.

Hygiene and washdown

  • Clean slashers and vehicles in late summer and autumn when seed is present.
  • Inspect and clean vehicles, plant and footwear before leaving an infested area, paying attention to tyres, radiators, belly plates, tracks and floor mats.
  • Wash down at a designated bay where runoff is contained and can be monitored for seedlings.
  • Record each washdown so the client has evidence of clean entry and exit.

Classification by state

  • Australia (national): No national listing. Managed under state and territory law.
  • Queensland: Restricted matter, category 3. Do not give it away, sell or release it into the environment. Everyone must also take all reasonable and practical steps to minimise its risks (the general biosecurity obligation).
  • New South Wales: Regional priority in 4 of 11 regions. Regional priority weed in Greater Sydney, Hunter, North Coast, South East. The general biosecurity duty applies: anyone dealing with it must prevent, eliminate or minimise the risk it poses.
  • Victoria: Not declared. Not declared under the Catchment and Land Protection Act 1994. Other Victorian laws may still apply.
  • South Australia: Not declared. Not declared under the Landscape South Australia Act 2019. Other laws may still apply.
  • Western Australia: Not listed. Not found in the Western Australian Organism List. Check with DPIRD before moving or keeping it.
  • Tasmania: Declared weed. Property managers are required by law to control declared weeds, and their import and sale are prohibited.
  • Northern Territory: Check NT list. There is no NT weed profile for it. Check the NT declared weeds list for its current status.
  • Australian Capital Territory: Not declared. Not declared under the Biosecurity Act 2023 (ACT). A general biosecurity duty still applies.

Legal obligations

Every state and territory places a duty on landholders and people working on land to prevent the spread of invasive species, such as the general biosecurity obligation in Queensland and the general biosecurity duty in New South Wales. Declarations and control requirements differ between states and local government areas, so check the current official list before work starts.

  • Queensland: Biosecurity Act 2014 (Qld), administered by Biosecurity Queensland (13 25 23)
  • New South Wales: Biosecurity Act 2015 (NSW), administered by NSW Department of Primary Industries and Regional Development

Sources