Giant Parramatta grass

Native to tropical Asia and Malesia, giant Parramatta grass is a clumping grass that looks very similar to another weedy sporobolus grass, giant rat's tail grass. It reduces pasture productivity and causes significant degradation of natural areas. Giant Parramatta grass is found from northern Queensland to the southern coast of New South Wales, with isolated infestations also found in Victoria and the Northern Territory.

Giant Parramatta grass is a restricted invasive plant under the Biosecurity Act 2014.

Scientific name

Sporobolus fertilis

Similar species


  • Clumping grass 0.8-1.6m tall.
  • Seed head is up to 50cm long and 1-2cm wide.
  • Branches of seed head are pressed to axis and overlapping when young, opening out as they mature.


  • Adapts to a wide range of soils and conditions.
  • Suited to conditions present in 60% of Queensland, including areas with low rainfall.

Distribution in Queensland

  • Found from northern Cape York to New South Wales border.

Life cycle

  • Seeds set throughout frost-free period of the year.
  • Produces up to 85,000 seeds per square metre each year with initial seed viability of about 90%.
  • Seeds can remain viable for up to 10 years.



  • Invades pastures and replaces more productive types of grass, especially after overgrazing or soil disturbance.
  • Causes loss in carrying capacity and decreased production by up to 80%.
  • Mature leaf blades are tough and difficult for cattle to graze.
  • Loosens teeth of grazing cattle and horses.

How it is spread

  • Spread by livestock, feral and native animals, vehicles, machinery and fast-flowing water.


Physical control

  • Maintain dense vigorous pastures.
  • Take great care to prevent dispersal by vehicles, implements and hay.

Herbicide control

Biological control

  • Biological control agents are under research for all weedy sporobolus grass species.

Legal requirements

  • Giant Parramatta grass is a restricted invasive plant under the Biosecurity Act 2014.
  • It must not be given away, sold, or released into the environment without a permit.
  • The Act requires everyone to take all reasonable and practical steps to minimise the risks associated with invasive plants and animals under their control. This is called a general biosecurity obligation (GBO).
  • At a local level, each local government must have a biosecurity plan that covers invasive plants and animals in its area. This plan may include actions to be taken on certain species. Some of these actions may be required under local laws. Contact your local government for more information.

More information