Palm grass (Setaria palmifolia)

Palm grass is a hardy, long-lived grass. It competes with native plants, pastures and crops.

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How does this weed affect you?

Palm grass can form large colonies. It:

• competes with native plants for water and nutrients
• invades pastures
• has hairy stems, which can cause irritation
• can reduce yields of some crops
• has thick prickly roots can stop other plants from establishing and growing.

What does it look like?

Palm grass is an upright plant that has large, tough leaves that are finely pleated. It usually grows to around 1.5 m tall. It has long, hairy stems and clusters of flowers that appear mainly in summer.

Leaves are:

• like a palm leaflet with fine pleats
• 27-90 cm long and  3-12 cm wide
• hairy underneath and the edges are rough
• pointed at the end 
• tough
• hanging

Leaves have a hairy ligule at the base. 

Seedheads are:

• loose and branching 
• up to 60 cm long and 2-10 cm wide
• made up of many spikelets (individual flowers each 2-4 mm long on short stalks)

Seeds are:

• pale brown
• around 2 mm long
• flattened and egg-shaped.

Stems are:

• upright and robust
• green
• hairy, especially near joints. 

Roots are:

• dense
• tough
• knotty rhizomes with rounded stems. (Rhizomes are underground stems that usually grow horizontally in the soil.)

Where is it found?

Palm grass is often grown as an ornamental garden plant and is commonly found in coastal areas of NSW, including Lord Howe and Norfolk Islands. It is also a weed elsewhere in Australia as well as New Zealand, the Pacific Islands and South and Central America.

It is native to tropical Asia.

What type of environment does it grow in?

Palm grass likes damp, shady areas with fertile, moist soil, but it can also grow in sunny locations and sandy soils. Once established it has some tolerance to drought, cold and salty conditions. It does not grow well in frost.

Plants grow in:

• forests 
• urban bushland
• waterways
• disturbed areas such as roadsides and gardens

How does it spread?

By seed

Plants are mainly spread by seed, which are moved by:

• wind and water
• birds
• people dumping garden waste.

By plant parts

New plants can also grow from root fragments These can be spread via water and people dumping garden waste.

References

Identic Pty Ltd. and Lucid central (2016). Environmental Weeds of Australia Fact sheet: Solanum torvum Sw. Retrieved 2018 from: https://keyserver.lucidcentral.org/weeds/data/media/Html/setaria_palmifolia.htm

Moreton Bay Regional Council Palm-leaf setaria grass fact sheet Retrieved 2018 from https://www.moretonbay.qld.gov.au/uploadedFiles/moretonbay/environment/vegetation/palm-leaf-setaria-grass.pdf

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

Weedbusters NZ. Weed Information Sheet-Palm grass Retrieved 2018 from https://www.weedbusters.org.nz/weed-information/setaria-palmifolia/59/

More information

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Control

Palm grass can be difficult to control because plants:

• have a very strong root system that can re-sprout 
• produce lots of seeds which are viable in the soil for several years.

Avoid contact with the hairs on the palm grass as they can cause irritation. Wear appropriate protective clothing when controlling this plant. 

Physical

Seedlings and small plants can be hand pulled or dug out. This is easiest when the soil is damp and loose. If possible remove roots from at least 10 cm below ground to avoid regrowth of the plant.

Disposal

Dispose of plants appropriately to prevent spread. Contact your local council weeds officer for advice on disposal.

Chemical control

Because plants re-sprout easily it is important to check control areas regularly and retreat if necessary.

Spraying

Apply herbicide to actively growing plants. Cover all of the foliage with the herbicide mix. 

Wiping

Ensure palm grass is at least 15 cm taller than the species to be retained. Apply when weeds are actively growing. To avoid damage to desirable species; heavily graze 4-6 weeks prior to application. In ungrazed areas, slash or burn and allow for regrowth to target weeds species.  If possible conduct two passes in opposite directions to obtain sufficient coverage of weed foliage.  Ground speed should not exceed 8 km/hr.

Herbicide options

See Using herbicides for more information.

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PERMIT 9792 Expires 30/11/2025
Flupropanate 745 g/L (Tussock®)
Rate: 3 L per ha
Comments: Selective broadacre control
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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PERMIT 9792 Expires 30/11/2025
Flupropanate 745 g/L (Tussock®)
Rate: 300 mL in 100 L of water
Comments: Spot spray
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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PERMIT 9792 Expires 30/11/2025
Flupropanate 745 g/L (Tussock®)
Rate: 500 mL in 10 L of water
Comments: Wiper application
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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PERMIT 9792 Expires 30/11/2025
Glyphosate 360 g/L (Various products)
Rate: 6 L per ha
Comments: Non-selective broadacre control
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 9792 Expires 30/11/2025
Glyphosate 360 g/L (Various products)
Rate: 1 L in 100 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 9792 Expires 30/11/2025
Glyphosate 360 g/L (Various products)
Rate: 3.3 L in 10 L of water
Comments: Wiper 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 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.

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Reviewed 2023