Gamba grass


Report gamba

You can now report a concern about unmanaged gamba grass.

Scientific name: Andropogon gayanus
Declaration status: Class A except in areas where it is classified as Class B

If you are a landowner or occupier with gamba grass on your land, you are legally responsible for controlling it.

Read the guide to identifying gamba grass and other Top End tussock grasses PDF (2.1 MB).

Also read any of the following about gamba grass:

You can also read the gamba grass annual report and snapshot on the Department of Environment, Parks and Water Security (DEPWS) website.

Gamba grass is a Weed of National Significance. For more information, go to the Australian Government's Department of Environment website.

Gamba grass is originally from Africa. It was introduced to the Northern Territory (NT) as a pasture species in the 1930s. Research and trials resulted in widespread plantings in pastoral and agricultural areas of the Top End.

It needs at least 600mm of rain each year. Gamba grass generally flowers in April, with seed production and fall from May to August. A second seeding may occur in November in response to an early wet season.

Gamba grass is tolerant of drought, fire and low nutrient soils found in north Australian savannas.

Gamba grass is suited to most Top End soil types, except for heavy clays.

Get free herbicide and loan of spray equipment from the Gamba Action Program.

For more information, get the gamba grass fact sheet on the Territory Stories website.

Gamba is a highly invasive weed that creates high fuel loads.

This can cause uncontrollable, hot and intense fires that affects people, properties and communities.

Gamba is a greater risk to the environment than native grass fires and destroys:

  • vegetation
  • large trees
  • animal shelters.

Gamba grass fire management has increased by millions of dollars. Find out more about how to control gamba grass.

Read the gamba fire mitigation compliance policy PDF (1.5 MB).

Gamba grass is a declared weed under section 7 of the Weeds Management Act 2001.

It has a split declaration based on its known distribution and density.

There are 2 declaration zones:

  • class B - growth and spread to be controlled
  • class A - to be eradicated in all areas of the NT except where it is classified as class B.

For more information on gamba grass declaration zones, read the 2014 gazette notice PDF (1.7 MB).

  • erect perennial tussock grass to 4m
  • robust stems covered in dense soft white hairs.
  • leaves broad and softly hairy to 1m, with a distinctive white midrib.
  • leaves stay green after native annual grasses have died off
  • leaves covered in fine soft hairs
  • seed heads v-shaped and fluffy, developing above the leaves on thick stems.

Gamba grass - habitGamba grass - leavesGamba grass - seed headsGamba grass - seedsGamba grass - spreadGamba grass - stems and branches

To find out more, get the gamba weed note on the DEPWS website.

If you are unsure, contact the Weed Management Branch.

Similar looking plants

While it is very important to control gamba grass on your property, it is also important to avoid accidentally removing certain beneficial native grasses that will compete with the invasive weeds and help the native bush to regenerate. The following plant species look similar to gamba grass:

Itch grass

Itch grass (Rottboellia cochinchinensis) is a native perennial grass that also has a distinctive white midrib, however stems and leaves are smooth, flexible and lack furry white hairs. There is little harm in confusing the two grasses and many people choose to control itch grass as well.

Itch grass

Giant spear grass

Giant spear grass (Heteropogon triticeus) is a native perennial grass that grows up to 1.8m tall with smooth stems and hairless nodes.

Giant spear grass (Heteropogon triticeus)

Northern cane grass

Northern cane grass (Mnesithea rottboellioides) is a native perennial grass that grows up to 2.5m tall with smooth, hairless, branching stems and sharp spiky rhizomes.

Northern cane grass / Mnesithea rottboellioides

Gamba grass currently affects up to 15,000 square kilometres of the NT, but has the potential to affect 380,000 sqkm of the NT. Most infestations are north of Katherine.

Data for this map was collected by the Weed Management Branch and other agencies.

Location and density of gamba grass

Gamba grass is a highly invasive weed.

The seeds are produced at the end of the wet season and can be carried by:

  • wind
  • vehicles
  • animals
  • people.

You must control gamba grass around property boundaries and along all roads and tracks.

Vehicles and machinery travelling through seeding gamba grass must be cleaned.

You must ensure all seeds and mud are removed. Mud may contain seeds.

You must clean before leaving an infested area. This is to stop the spread of gamba grass to other areas.

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Last updated: 02 December 2021

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