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Chilean needle grass (Nassella neesiana)

A tussock grass whose sharp seeds damage sheep pelts, carcases and eyes. It is hard to tell apart from native spear grasses, so early identification matters.

Key facts

Type: Weed, grass.

Native to: South America.

Established in: QLD, NSW, ACT, VIC, SA.

Best time to act: Treat before seed set in late spring.

Identification

  • Perennial tussock grass to 1 m tall.
  • Seeds with a sharp point and a long twisted awn up to 9 cm.
  • A distinctive crown (corona) at the top of the seed, just below the awn.
  • Also produces hidden seeds in the stem joints.
  • Look-alike: Native spear grasses (Austrostipa spp.) lack the corona at the top of the seed; confirm with a specialist.

Where it grows

Temperate pasture, roadsides and native grassland.

Why it matters

  • Seeds penetrate wool, skin and carcases, causing downgrades.
  • Reduces pasture productivity.
  • Invades native grasslands.

How it spreads

  • Seeds carried on livestock, vehicles, slashers and in hay.
  • Contaminated fodder and soil.

Control options

  • Report new infestations early.
  • Spot spray or chip out isolated plants before seed set.
  • Competitive pasture management and grazing management to reduce seed set.

Hygiene and washdown

  • Slash or mow clean areas before infested areas, then clean equipment.
  • Avoid moving stock from infested paddocks when seed is ripe.
  • 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): Weed of National Significance. One of 32 nationally agreed priority weeds, managed through national strategies with all states and territories.
  • 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: Sale prohibited; Regional priority in 6 of 11 regions. It must not be imported into NSW or sold anywhere in the state. Regional priority weed in Central Tablelands, Central West, Hunter, Murray, North West, Riverina. The general biosecurity duty applies: anyone dealing with it must prevent, eliminate or minimise the risk it poses.
  • Victoria: Restricted weed. Where it is a restricted weed, trade in it (including the plant, its seed or contaminated material) is prohibited.
  • South Australia: Declared plant. Depending on the declaration, it can be an offence to move it on public roads or sell it, and landowners may be required to control it on their land.
  • Western Australia: Declared pest (C1), prohibited. C1 Exclusion: to be kept out of WA, or out of the parts of WA where it is not established. Report any sighting to DPIRD. It must not be brought into WA (prohibited organism).
  • 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: Declared pest, prohibited. It is a declared pest throughout the ACT. Dealing with it, such as selling, moving or keeping it, is prohibited.

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
  • Australian Capital Territory: Biosecurity Act 2023 (ACT), administered by ACT Biosecurity
  • Victoria: Catchment and Land Protection Act 1994 (Vic), administered by Agriculture Victoria
  • South Australia: Landscape South Australia Act 2019 (SA), administered by the regional landscape board

Sources