Giant reed (Arundo donax)

Also known as: elephant grass

Giant reed is a tall perennial grass up to 8 m, that grows in large cane-like clumps. It outcompetes native plants, reduces habitat for native animals and can increase fire intensity and frequency.

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How does this weed affect you?

Giant reed grows quickly, forming large dense stands that:

• outcompete native plants
• reduce food and habitat for native animals
• are tall enough to reach power lines and spark fires
• are very flammable even when green and can increase fire intensity and frequency
• change water flows and block streams
• lower ground water tables.

Giant reed contains toxins that make it unpalatable.

What does it look like?

Giant reed is a clumping perennial grass up to 8 m tall.

Leaves are:

• up to 100 cm long and 8 cm wide
• attached to the stem with ribbed sheath a
• pointed at the tip
• sometimes variegated with whitish markings
• alternate along the stem.

The ligule, which grows were the leaf blade meets the sheath, is a membrane fringed with hairs 1.5–3 mm long.

Flowerheads are:

• silky, erect and feather-like
• in loose branching clusters
• 30 – 70 cm long at the end of the stems
• light brown or purplish when young, becoming white or beige as they mature
• present from spring through to early winter.

Seeds are:

• very rarely produced outside of the plant’s natural range and no viable seeds have been found in Australia
• 1-2 mm long oblong grains.

Stems are:

• up to 4 cm in diameter and usually hollow
• occasionally branched
• woody.

Rhizomes are:

• 5 to 50 cm long
• thick and fleshy
• can grow up to 1 m deep.

Where is it found?

Giant reed mainly occurs along the central and northern coast of NSW. It is found throughout Australia and is most common around major urban centres. It was most likely brought into Australia as a garden plant or for erosion control.

Giant reed is native to India, Europe, Asia and Madagascar.

What type of environment does it grow in?

Giant reed mostly grows in subtropical and warm temperate climates; however, it can tolerate tropical, arid and semi-arid conditions. It grows in areas with 300-4000 mm of rainfall per year. Plants do not tolerate frosts well.

Giant reed grows in a wide range of soil types including saline infertile soils, heavy clays and course river sands. It tolerates waterlogged soil, but grows best in fertile, well-drained soil with high moisture levels. It thrives in full sun and disturbed sites. 

Giant reed grows:

• along riverbanks, lakes and around dams
• in estuaries, wetlands and swamps
• in irrigation channels and drainage lines
• in urban bushland, parks and gardens
• along roadsides
• in open forests.

Maps and records

• Recorded presence of Giant reed during property inspections (Map: Biosecurity Information System - Weeds, 2017-2026)
  These records are made by authorised officers during property inspections under the Biosecurity Act 2015. Officers record the presence of priority weeds in their council area and provide this to the NSW Department of Primary Industries. Records reflect the presence of the weed on the date of inspection.
  
  

How does it spread?

By plant parts

In Australia, spread is via plant parts. Rhizomes and stems with at least one node can produce new plants. These pieces can be productive even if less than 5 cm long. Plant parts can be spread by moving water, by people dumping garden waste or in soil.

By seed

Giant reed rarely produces seed. No viable seed has been in Australia. If seeds are produced, they are mostly moved by wind and water.

References

Bell, G. P. (1998). Ecology and management of Arundo donax, and approaches to riparian habitat restoration in southern California. In J.H. Brock, M. Wade, P. Pyšek, D. Green. (Eds), : Plant Invasions. Studies from North America and Europe. (pp. 103-113). Backhuys & Leiden, The Netherlands.

Csurhes, S. (2016). Invasive Plant Risk assessment Giant reed Arundo donax. 2nd edition Department of Agriculture and Fisheries Biosecurity Queensland.

Identic Pty Ltd. and Lucid. (2016). Environmental Weeds of Australia Fact sheet: Arundo donax L. Retrieved: 26 August 2025 from: https://keyserver.lucidcentral.org/weeds/data/media/Html/arundo_donax.htm

Pilu, R., Bucci, A., Badone, F. C., & Landoni, M. (2012). Giant reed (Arundo donax L.): A weed plant or a promising energy crop. Afr. J. Biotechnol, 11(38), 9163-9174.

PlantNET (The NSW Plant Information Network System). Royal Botanic Gardens and Domain Trust, Sydney. Retrieved 22/09/2025 from: https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Arundo~donax

Valez-Gavilan, J. (2024) CABI Data Sheet: Arundo donax (giant reed). Retrieved 26 August 2025 from: https://www.cabidigitallibrary.org/doi/10.1079/cabicompendium.1940

More information

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Control

Successful weed control requires follow up after the initial efforts. This means looking for and killing regrowth or new seedlings. Using a combination of control methods is usually more successful.

Physical control

By hand

Digging out plants can be effective for small infestations. All rhizomes must be removed. This technique can be more selective than using herbicides and can prevent damage to nearby native plants.

By machine

Remove larger stands by bulldozer or tractor. Follow up by digging out rhizomes or using herbicides to control regrowth.

Chemical control

Spraying

Spray actively growing plants, cover all the foliage. The plants can be very tall therefore, it can be more efficient to cut the plants at ground level, then wait for approximately 6 weeks to spray the regrowth.

Cut stump method

Cut stems between 5 and 10 cm above the ground. Apply herbicide to the remaining stems within 15 seconds of cutting.

Herbicide options

See Using herbicides for more information.

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PERMIT 9907 Expires 31/03/2030
Glyphosate 360 g/L (Various products)
Rate: 200 mL per 10 L of water
Comments: Spot spray.
Withholding period: Nil.
Herbicide group: 9 (previously group M), Inhibition of 5-enolpyruvyl shikimate-3 phosphate synthase (EPSP inhibition)
Resistance risk: Moderate

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PERMIT 9907 Expires 31/03/2030
Glyphosate 360 g/L (Various products)
Rate: 1 part glyphosate to 1.5 parts of water
Comments: Cut stump application.
Withholding period: Nil.
Herbicide group: 9 (previously group M), Inhibition of 5-enolpyruvyl shikimate-3 phosphate synthase (EPSP inhibition)
Resistance risk: Moderate

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Biosecurity duty

The content provided here is for information purposes only and is taken from the NSW Biosecurity Act 2015 and its subordinate legislation, and the Regional Strategic Weed Management Plans (published by each Local Land Services region in NSW). It describes the state and regional priorities for weeds in New South Wales, Australia.

Area	Duty
All of NSW	General Biosecurity Duty All pest plants are regulated with a general biosecurity duty to prevent, eliminate or minimise any biosecurity risk they may pose. Any person who deals with any plant, who knows (or ought to know) of any biosecurity risk, has a duty to ensure the risk is prevented, eliminated or minimised, so far as is reasonably practicable.
Central Tablelands An exclusion zone is established for Blayney Council, Lithgow Council, Oberon Council, Cabonne and Orange City Council areas. A core infestation area is established for Bathurst Regional Council, Mid-Western Regional Council and Cowra Shire Council.	Regional Recommended Measure* (for Regional Priority - Containment) Within exclusion zone: Land managers should mitigate the risk of the plant being introduced to their land. Land managers should eradicate the plant from the land and keep the land free of the plant. A person should not deal with the plant, where dealings include but are not limited to buying, selling, growing, moving, carrying or releasing the plant. Within core infestation area: Land managers should mitigate the risk of the plant being introduced to their land. Land managers should mitigate spread of the plant from their land. A person should not buy, sell, move, carry or release the plant into the environment. Land managers should reduce the impact of the plant on assets of high economic, environmental and/or social value.
Central West	Regional Recommended Measure* (for Regional Priority - Eradication) Land managers should mitigate the risk of the plant being introduced to their land. Land managers should eradicate the plant from the land and keep the land free of the plant. A person should not deal with the plant, where dealings include but are not limited to buying, selling, growing, moving, carrying or releasing the plant. Notify local control authority if found.
Greater Sydney	Regional Recommended Measure* (for Regional Priority - Asset Protection) Land managers should mitigate the risk of the plant being introduced to their land. Land managers should mitigate spread of the plant from their land. A person should not buy, sell, move, carry or release the plant into the environment.
Hunter	Regional Recommended Measure* (for Regional Priority - Asset Protection) Land managers should mitigate the risk of the plant being introduced to their land. Land managers should mitigate spread of the plant from their land. A person should not buy, sell, move, carry or release the plant into the environment. Land managers should reduce the impact of the plant on assets of high economic, environmental and/or social value.
North Coast Exclusion (eradication) zone: Lord Howe Island, Port Macquarie-Hastings LGA. Core infestation (containment) zone: Ballina Shire LGA, Bellingen Shire LGA, Byron Shire LGA, Clarence Valley LGA, Coffs Harbour City LGA, Kempsey Shire LGA, Kyogle Shire LGA, Lismore City LGA, Nambucca Valley LGA, Richmond Valley LGA, Tweed Shire LGA.	Regional Recommended Measure* (for Regional Priority - Containment) Whole of region: Land managers should mitigate the risk of the plant being introduced to their land. A person should not buy, sell, move, carry or release the plant into the environment. Exclusion zone: Notify local control authority if found. Land managers should eradicate the plant from the land and keep the land free of the plant. Core infestation: Land managers should mitigate spread of the plant from their land. Land managers should reduce the impact of the plant on assets of high economic, environmental and/or social value.
Western An exclusion zone is established for all lands in the Western Local Land Services region, except the core infestation area, which comprises all lands within the Wentworth Shire Council.	Regional Recommended Measure* (for Regional Priority - Containment) Whole of region: Land managers mitigate the risk of new weeds being introduced to their land. Within exclusion zone: Land managers should eradicate the plant from the land and keep the land free of the plant. A person should not deal with the plant, where dealings include but are not limited to buying, selling, growing, moving, carrying or releasing the plant. Notify local control authority if found. Within core infestation: Land managers should mitigate spread of the plant from their land. A person should not buy, sell, move, carry or release the plant into the environment. Land managers should reduce the impact of the plant on assets of high economic, environmental and/or social value.
	*To see the Regional Strategic Weeds Management Plans containing demonstrated outcomes that fulfil the general biosecurity duty for this weed click here

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Reviewed 2025