Giant Parramatta grass (Sporobolus fertilis)

Giant Parramatta grass is a tall, fast-growing tussock grass. It is common in coastal areas and takes over pastures, reducing productivity

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How does this weed affect you?

Giant Parramatta grass:

• outcompetes pastures
• reduces productivity and the value of grazing land
• competes with native plants
• increases fuel loads, which increases fire intensity and/or frequency.

What does it look like?

Giant Parramatta grass is a dense, perennial, tussock grass. It usually grows up to 2 m tall.

Leaves are:

• long and thin with pointed tips
• up to 110 cm long and 5 mm wide
• flat, folded or rolled inwards
• ribbed and hairless
• sometimes drooping

The leaf sheath is ribbed and hairless and the ligule at the junction of the leaf and leaf sheath is a fringe of small hairs.[BV3] 

 Flowerheads are:

• dense with many branches held close to the main stems (some mature branches droop away from the central stalk)
• 25–45 cm long and 1–2 cm wide
• made up of dark green spikelets1.5-2 mm long
• present from spring to autumn

Seeds are:

• 0.8–1.2 mm long and 0.5–0.75 mm wide
• yellowish-brown or reddish-brown when mature
• sticky when mature.

Stems are:

• arranged like a fan
• usually not branched
• 2-5 mm in diameter
• hairless
• slightly wiry

Similar looking plants

It is difficult to identify Sporobolus grasses prior to seed set. Giant Parramatta grass looks like other weedy Sporobolus grasses including:

• Parramatta grass (Sporobolus africanus), which is usually shorter (<1 m tall) and has smaller seed heads (up to 18 cm).
• Giant rat’s tail grass (Sporobolus pyramidalis) which is very similar but as the seed head matures its branches move apart to form a pyramid.

Giant Parramatta grass also looks similar to some native Sporobolus grasses including:

• slender rats-tail grass (Sporobolus creber)
• slender rats-tail grass (Sporobolus elongatus)

Both these species are smaller (usually less than 100 cm tall) and have less dense seedheads.

Where is it found?

In NSW, giant Parramatta grass mostly grows along the east coast in the North Coast, Hunter Greater Sydney and South East regions. Plants have also been found in the North West and Western regions.

It is native to Asia and was accidentally brought into Australia.

What type of environment does it grow in?

Giant parramatta grass grows in tropical, sub-tropical and warm temperate regions. It grows best in high rainfall areas, though plants, including seedlings are tolerant to dry conditions. Plants have been found growing in:

• pastures
• disturbed sites such as roadsides and trails
• open woodlands, grasslands, riparian areas and wetlands
• parks.

Maps and records

• Recorded presence of Giant Parramatta grass 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 seed

Plants can produce seeds within 3 months of germinating. Seed production can be up to 85,000 seeds per square metre each year. Seed viability is high, over 90% and seeds can remain viable for up to 10 years. 

Mature seeds are sticky when wet. They are spread by:

• livestock
• native animals and feral animals
• people on clothing or footwear
• vehicles and machinery
• flowing water
• wind, though usually no more than 10 m
• contaminated agricultural produce.

References

Austin, P., March, N. & Johnson, K. (2011). Caring for our Country Biosecurity Weed Management Guide: Weedy Sporobolus grasses. Queensland, DEEDI. Retrieved 11 June 2024 from: https://www.researchgate.net/publication/328280009_Weed_Management_Guide_-_Weedy_Sporobolus_Grasses

Department of Primary Industries and Fisheries Queensland (2007). Weedy Sporobolus Grasses - Best Practice Manual. Queensland Government. Retrieved 11 June 2024 from: https://era.daf.qld.gov.au/id/eprint/8712/1/Weedy%20Sporobolus%20grasses_Best%20practice%20manual_rev%20ed_2007.pdf

Identic Pty. Ltd.& Lucid. (2016) Weeds of Australia Fact Sheet: Sporobolus fertilis (Steud.) W.D. Clayton. Retrieved 11 June 2024 from: https://keyserver.lucidcentral.org/weeds/data/media/Html/sporobolus_fertilis.htm

PlantNET (The NSW Plant Information Network System). Royal Botanic Gardens and Domain Trust, Sydney. Retrieved 11 June 2024 from https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Sporobolus~fertilis

Queensland Government. (2021). Restricted invasive plants: Giant Parramatta grass. Retrieved 11 June 2024 from: https://www.business.qld.gov.au/industries/farms-fishing-forestry/agriculture/biosecurity/plants/invasive/restricted/giant-parramatta-grass

Simon, B. K., & Jacobs, S. W. (1999). Revision of the genus Sporobolus (Poaceae, Chloridoideae) in Australia. Australian Systematic Botany, 12(3), 375-448.

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.

Prevention

Check for Parramatta grass regularly as plant can mature and set seed within 3 months.

Avoid moving vehicles and machinery through infested areas if possible. Clean machinery, vehicles and equipment that have been in infested areas before moving to a clean paddock.

Avoid moving stock from infested areas into clean areas. If necessary, hold the stock in yards for at least five days.

Where possible, minimise soil disturbance and bare ground. This can be done by maintaining healthy pastures, managing livestock numbers and maintaining litter in areas where there are no live plants.

Pasture management

Depending on the site and level of infestation, management may include fertilising to maintain ground cover and competitive pastures, pasture replacement, planting fodder crops, and managing livestock numbers.

Pasture management for a variety of situations and levels of infestation is detailed in the Weedy Sporobolus Grasses Manual, which is linked in the More information section below.

Hand weeding

Individual, isolated plants or very small infestations can be dug out. If the plants have seed heads, cut them off and bag them before digging plants out to limit the spread of seeds. Contact your local council for advice on how to dispose of the seedheads.

Chemical control

Using fertiliser to improve pasture growth can complement chemical control.  

Spot spraying

Spray actively growing plants. Cover all the foliage evenly.

Boom spraying

Spray when plants are actively growing. Check the permits and labels for detailed conditions.

Wick wipers

Wipers apply herbicide directly onto the leaves. This can better target the chemical and minimise damage to other species. Apply when the plants are actively growing.

Granule herbicide

Spot application of granules can be applied all year round.

Herbicide options

See Using herbicides for more information.

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PERMIT 9792 Expires 31/12/2030
Glyphosate 360 g/L (Various products)
Rate: 3.3 L per 10 L of water
Comments: Wiper suppression. Apply when plant is actively growing.
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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Flupropanate 745 g/L (Various products)
Rate: 200 mL per 100 L of water
Comments: High volume spot spray. In Northern NSW apply from July to December inclusive, during the drier time of year. To obtain better herbicide selectivity and less damage to desirable pasture species, apply when the pasture is dormant, semi-dormant.
Withholding period: Spot spray: Do NOT graze or cut for stock feed for at least 14 days. Blanket spray: Do NOT graze, or cut for stock feed for at least 4 months. If stock are grazed in treated areas after required time has passed, remove stock from treated areas and do NOT slaughter or milk for human consumption until they have been on clean feed for at least 14 days.
Herbicide group: 15 (previously group J), Inhibition of very long chain fatty acid synthesis (VLCFA inhibitors)
Resistance risk: Moderate

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Flupropanate 745 g/L (Various products)
Rate: 1.5–2.0 L/ha
Comments: Boom spray. Use the higher rate for heavy infestations. In Northern NSW apply from July to December inclusive, during the drier time of year. To obtain better herbicide selectivity and less damage to desirable pasture species, apply when the pasture is dormant, semi-dormant.
Withholding period: Spot spray: Do NOT graze or cut for stock feed for at least 14 days. Blanket spray: Do NOT graze, or cut for stock feed for at least 4 months. If stock are grazed in treated areas after required time has passed, remove stock from treated areas and do NOT slaughter or milk for human consumption until they have been on clean feed for at least 14 days.
Herbicide group: 15 (previously group J), Inhibition of very long chain fatty acid synthesis (VLCFA inhibitors)
Resistance risk: Moderate

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Flupropanate 86.9 g/kg (GP Flupropanate)
Rate: 15 kg /ha
Comments: Evenly distribute granules. Apply when the pasture is dormant or semi-dormant. Optimum application time is autumn and early spring. Do not apply in severe droughts or to weeds retarded by burning.
Withholding period: Do not graze or cut for stock feed areas which have received any treatment other than spot treatment for at least 4 months. Spot treatment: Do not graze or cut for stock feed for at least 14 days. If stock are grazed in treated areas after required time has passed, remove stock from treated areas and do NOT slaughter or milk for human consumption until they have been on clean feed for at least 14 days. This requirement applies permanently to treated areas.
Herbicide group: 15 (previously group J), Inhibition of very long chain fatty acid synthesis (VLCFA inhibitors)
Resistance risk: Moderate

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Flupropanate 86.9 g/kg (GP Flupropanate)
Rate: 1.5 g/m2
Comments: Spot application of granules can be applied all year round.
Withholding period: Do not graze or cut for stock feed areas which have received any treatment other than spot treatment for at least 4 months. Spot treatment: Do not graze or cut for stock feed for at least 14 days. If stock are grazed in treated areas after required time has passed, remove stock from treated areas and do NOT slaughter or milk for human consumption until they have been on clean feed for at least 14 days. This requirement applies permanently to treated areas.
Herbicide group: 15 (previously group J), Inhibition of very long chain fatty acid synthesis (VLCFA inhibitors)
Resistance risk: Moderate

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Glyphosate 360 g/L (Various products)
Rate: 10–15 mL per 1 L of water
Comments: Spot spray. Apply when plants are actively growing in the vegetative stage to early seed head stage. Follow up treatments will be required.
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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Glyphosate 360 g/L (Various products)
Rate: 6.0 L/ha OR 3L followed by 3L/ ha split treatment
Comments: Boom application for pasture replacement/improvement and best done as a split treatment after at least 20 cm of new growth.
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	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.
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 West An exclusion zone is established for all lands in the region, except the core infestation area comprising the: Tamworth Regional 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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Disclaimers

Pasture improvement may be associated with an increase in the incidence of certain livestock health disorders. Livestock and production losses from some disorders are possible. Management may need to be modified to minimise risk. Consult your veterinarian or adviser when planning pasture improvement. The Biodiversity Conservation Act 2016 and Local Land Services Amendment Act 2016 restrict some pasture improvement practices where existing pasture contains native species. Contact Local Land Services for further details.

Reviewed 2024