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Hawkweed (Hieracium spp.)

Hawkweeds are introduced, perennial weeds that can form dense patches and threaten biodiversity, conservation areas and native grasslands. They are highly invasive, so early detection and repeated control are important.

Key facts

Type: Weed, herb.

Native to: Mainly Europe and temperate Asia..

Established in: NSW.

Other names: Yellow hawkweed.

Best time to act: Inspect in spring and summer when plants are easier to spot, and treat before seed heads mature.

Identification

  • Look for a perennial herb with a rosette of leaves at ground level and usually a single upright flowering stem.
  • Leaves are stalked or stalkless, with smooth, toothed or occasionally lobed edges.
  • Plants may spread by stolons, which run along the ground and can form new plants.
  • Flower heads may be solitary or in a cluster, with numerous yellow florets and an often bell-shaped or tapered base.
  • The small, ribbed seeds have a tuft of pale bristles.
  • Look-alike: Other rosette-forming weeds with yellow daisy-like flowers, such as catsear and dandelion, can look similar.
  • Look-alike: Some plants formerly included in Hieracium are now placed in the closely related genus Pilosella, so seek expert identification when uncertain.

Where it grows

In Australia, hawkweeds are of concern in cool, open grasslands and other suitable sites, including conservation areas and native grasslands.

Why it matters

  • Hawkweeds can invade native grasslands and conservation areas.
  • They are a major threat to biodiversity.
  • Dense patches can compete with native vegetation and make infestations difficult to manage.

How it spreads

  • The bristled seeds can be carried by wind and may establish new infestations away from parent plants.
  • Some plants also spread by stolons, which can root and form new plants.

Control options

  • Remove small, isolated plants carefully, including the roots and any stolons, and contain flowering or seed-bearing material to prevent further spread.
  • Where removal is not suitable, use only herbicides registered for the target weed and site, strictly following the product label and local requirements.
  • Revisit treated sites and continue control, because missed plants or regrowth can re-establish an infestation.
  • Report suspected infestations to the relevant state or territory biosecurity agency; in New South Wales, contact a council weeds officer or NSW Department of Primary Industries.

Hygiene and washdown

  • Clean soil and plant material from boots, tools, vehicles and machinery before leaving an infested site, and dispose of the material where it cannot spread.
  • Avoid moving contaminated soil or fodder to clean areas.
  • 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: Not prohibited or restricted. Not listed as prohibited or restricted matter in Queensland. Everyone must also take all reasonable and practical steps to minimise its risks (the general biosecurity obligation).
  • New South Wales: Not a priority weed. Not a state or regional priority weed in NSW. The general biosecurity duty applies: anyone dealing with it must prevent, eliminate or minimise the risk it poses.
  • Victoria: State prohibited weed. State prohibited weeds are the highest priority: the Victorian Government is responsible for eradicating them, so report any sighting to Agriculture Victoria.
  • 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.

  • New South Wales: Biosecurity Act 2015 (NSW), administered by NSW Department of Primary Industries and Regional Development

Sources