Serrated tussock is a drought tolerant grass with low feed value. It takes over pastures and native vegetation.
Serrated tussock is not palatable to stock. Animals grazing on it become malnourished.
Serrated tussock can:
The native vegetation communities at risk include:
Serrated tussock can completely take over new areas within 4 years. It is hard to get rid of. A single plant can produce up to 140,000 seeds each season. Control is costly and herbicides used to control serrated tussock impact other grasses, especially natives.
Serrated tussock has extremely low nutritional value. All animals forced to graze serrated tussock will lose condition. Sheep lose weight and eventually die, with the stomach full of partly digested tussock at death.
Stock grazing dense serrated tussock for short to medium periods need feed supplements to provide energy and protein.
Serrated tussock grows in upright tussocks up to 45 cm tall and 25 cm wide. In spring the clumps are light green with brown tips to the leaves. In late spring and early summer the clumps have a purple tinge when the seed heads emerge fully. Plants remain green in summer when other grasses turn brown. After frost the clumps turn a golden yellow.
Serrated tussock has a small, thin structure at the base of the leaf blade. This is a ligule, and can look like a small piece of tissue paper. The ligule is 1 mm long, smooth and milky coloured.
Serrated tussock looks like some native Australian grasses. Similar looking native grasses include corkscrew grass, poa tussock, snowgrass and wallaby grass. It could be serrated tussock if the:
Figure A. Ligules of (a) serrated tussock; (b) corkscrew grass; (c) snowgrass; (d) poa tussock; (e) red-anthered wallaby grass.
Serrated tussock is closely related to Mexican feather grass (Nassella tenuissima) and Chilean needle grass (Nassella neesiana). Serrated tussock tends to be shorter (45 cm high).
You can tell them apart when the plants have seeds:
The main infestations are in the Central and Southern Tablelands of NSW. There is some serrated tussock on the Northern Tablelands.
It was first introduced to Australia in the early 1900s and first identified in 1935. In 1976, 680 000 ha of NSW had serrated tussock. By 2003 this area had increased to 820 000 ha. The area with serrated tussock within NSW continues to increase.
Serrated tussock is native to South America. It is a weed in New Zealand, South Africa, Europe and North America.
Serrated tussock prefers to grow on the tablelands of NSW, although it can be found on the coast and slopes. The optimum temperature range is 10 - 15 degrees C. It tolerates:
It does not like:
Serrated tussock seeds can spread long distances by wind and water. Wind is the main mechanism of spread. The ripe seed heads break of at the base and are carried long distances by wind - 10 km or more if conditions are favourable. Seeds have been known to move 60 km downstream from the nearest infestation on the banks of the Macquarie River.
Seeds also spread with feed, animals and machinery. Animals can pick up seeds in hooves, fleeces or coats. Serrated tussock seeds remain viable passing through an animal’s gut.
Serrated tussock colonises bare areas. Drought causing bare ground favours serrated tussock. Sandy, nutrient poor soils are at most risk.
Long term control of serrated tussock needs to consider that:
Learn to identify serrated tussock. Keep checking feedout areas, paddocks and windbreaks for serrated tussock plants and control them. Delaying control of odd plants or light or scattered plants allows a quick transition to more and more plants. These quickly become more difficult and costly to control.
Maintaining healthy pastures is the best long-term defence against serrated tussock. Serrated tussock is unlikely to establish in a good perennial pasture with legumes. Thin and bare patches in the pasture are at most risk of invasion.
Dense pastures with 100% groundcover can prevent seedling establishment. To maintain healthy pastures:
Cropping with weed control in spring and autumn reduces the weed seed bank. Control weeds for at least one year before sowing pasture.
Suitable crops include oats, winter wheats and forage brassicas. Disc ploughs can break up tussock clods and encourage seed germination. Avoid discing on shallow soils or slopes to protect the soil.
Serrated tussock is not very palatable and has little feed value. Animals can graze it for short periods, but will lose condition. Animals favour other pasture species over serrated tussock. This promotes the dominance of the weed. Pastures will deteriorate with continuous grazing.
Graze in autumn to remove dead plant litter and promote subterranean clover. Don’t over graze. Redgrass (Bothriocloa macra) competes well with serrated tussock.
Avoid grazing new pastures unless conditions are very good. Then a quick, light graze with cattle in spring can encourage pasture growth.
Remove individual plants with a mattock in small, isolated patches. Bag and dispose of the pulled out plants. Also dispose of soil attached to roots as it may contain seeds. Tussocks with flowers should be burnt after removal.
Sow pasture seed where the ground is bare.
Planting trees with a dense canopy like pines is an effective long-term strategy. It will take many years for trees to be large enough to suppress serrated tussock. Use other control methods in the meantime.
Before planting trees:
Commercial forestry may be an option. Seek expert advice before investing in forestry projects.
There are no effective biological control agents in Australia for serrated tussock.
Most herbicides used to control serrated tussock contain either glyphosate or flupropanate. Pasture species have variable tolerance to these herbicides. Check which pasture species are present. Follow up is essential for successful control.
Herbicides are most effective in combination with healthy, competitive pastures. Repeated use of the same herbicide can lead to herbicide resistance.
Always observe grazing withholding periods following herbicide treatments in pastures.
Legumes and some native pasture species (e.g. weeping grass, wallaby grass, spear grass) can be killed by flupropanate herbicides. Kangaroo grass and redgrass are more tolerant.
Flupropanate can remain active in the soil for up to two years. Residual activity depends on the amount of rainfall. Residual activity is longer with low rainfall or drought. Flupropanate continues killing serrated tussock seedlings until 100mm of leaching rainfall has fallen.
The herbicide washes out faster from sandy soils than clay soils. Do not sow a new pasture or crop until flupropanate is likely to have washed out of the root zone.
Flupropanate takes several months to kill serrated tussock. It may not stop seed production when applied after mid-August. Apply 2 – 4 weeks before seed heads emerge (indicated by thickening of tillers). After seeding, use a mix of glyphosate + flupropanate.
Label rates of flupropanate control serrated tussock with minimal damage to young native trees.
Use glyphosate for a complete knockdown of serrated tussock and other weeds. Glyphosate has no residual effect. Carefully timed applications can allow some selectivity - killing serrated tussock whilst preserving dormant desirable pastures. It is important to get good spray coverage of all the target plant or it may recover.
Apply glyphosate:
Avoid using glyphosate when:
Glyphosate can be unreliable when:
Spot spray individual clumps or small patches year round, before plants set seed. Calibrate spray equipment to ensure you apply the correct rate of herbicide. Only spray the tussock plants. A spray shield can minimise damage to surrounding plants. Check paddocks after spraying for any missed plants.
Herbicide can be applied with boomsprays or aircraft for larger areas.
Graze to reduce the height of desirable pasture species before using wipers. Both flupropanate and glyphosate are suitable.
Wiping is only effective on large tussocks. Repeat treatment as smaller tussocks mature. Use the wiper in two directions to improve efficacy.
Herbicide resistant plants that spread by seed are harder to control. Serrated tussock is not reported as resistant to glyphosate. It has become resistant to flupropanate in some areas.
Herbicide resistance is more likely to develop when treating large areas with a lot of weeds. Avoid herbicide resistance developing by:
See Using herbicides for more information.
PERMIT 9792 Expires 30/11/2025
Glyphosate 360 g/L
(Roundup®)
Rate: 1 L per 2 L of water
Comments: Wick wiping application.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate
Flupropanate 745 g/L
(Tussock®)
Rate: 1.5–2.0 L/ha
Comments: Boom and aerial application. June to August inclusive. Four-month withholding period for blanket application.
Withholding period: Don't graze cows or goats that are being milked on treated areas. Blanket sprayed pastures - grazing or cutting for stock feed - 120 days. Spot sprayed areas - grazing or cutting for stock feed - 14 days. Don't graze stock on treated areas for 14 days prior to slaughter.
Herbicide group: J, Inhibitors of fat synthesis (Not ACCase inhibitors)
Resistance risk: Moderate
Flupropanate 745 g/L
(Tussock®)
Rate: 100–200 mL per 100 L of water
Comments: Spot spray from September to May. Four month withholding period for blanket application.
Withholding period: Don't graze cows or goats that are being milked on treated areas. Blanket sprayed pastures - grazing or cutting for stock feed - 120 days. Spot sprayed areas - grazing or cutting for stock feed - 14 days. Don't graze stock on treated areas for 14 days prior to slaughter.
Herbicide group: J, Inhibitors of fat synthesis (Not ACCase inhibitors)
Resistance risk: Moderate
Flupropanate 86.9 g/kg
(GP Flupropanate)
Rate: 15kg per ha
Comments: Apply February to December inclusive. Four month withholding period for blanket application.
Withholding period: Don't graze cows or goats that are being milked on treated areas. Blanket treated areas - grazing or cutting for stock feed - 4 months. Spot treated areas - grazing or cutting for stock feed - 14 days. Don't graze stock on treated areas for 14 days prior to slaughter.
Herbicide group: J, Inhibitors of fat synthesis (Not ACCase inhibitors)
Resistance risk: Moderate
Flupropanate 86.9 g/kg
(GP Flupropanate)
Rate: 1.5g/m2
Comments: Spot application apply all year round.
Withholding period: Don't graze cows or goats that are being milked on treated areas. Blanket treated areas - grazing or cutting for stock feed - 4 months. Spot treated areas - grazing or cutting for stock feed - 14 days. Don't graze stock on treated areas for 14 days prior to slaughter.
Herbicide group: J, Inhibitors of fat synthesis (Not ACCase inhibitors)
Resistance risk: Moderate
Glyphosate 360 g/L
(Roundup®)
Rate: 0.7–1.3 L to 100 L of water
Comments: Spot spray application.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate
Glyphosate 360 g/L
(Roundup®)
Rate: 4.0–6.0 L/ha
Comments: Boom spray. Apply to actively growing, stress-free plants.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate
Glyphosate 360 g/L
(Roundup®)
Rate: 0.75–1.25 L/ha
Comments: Spray topping application. Apply to actively growing, stress-free plants.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate
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 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. |
All of NSW |
Prohibition on dealings
Must not be imported into the State or sold |
Central Tablelands |
Regional Recommended Measure*
Land managers should mitigate the risk of new weeds being introduced to their land. Land managers should mitigate spread from their land. The plant should not be bought, sold, grown, carried or released into the environment. Protect conservation areas, natural environments and primary production lands that are free of serrated tussock |
Central West
Exclusion zone: whole region except for the core infestation area that is bounded by the Central West Local Land Services boundary north along Burrendong Way to Stuart Town, east along Mookerawa Road to Burrendong Dam, and east along Oaky Creek, bounded by the Central West Local Land Services boundary |
Regional Recommended Measure*
Whole region: The plant should not be bought, sold, grown, carried or released into the environment. Exclusion zone: The plant should be eradicated from the land and the land kept free of the plant. Land managers should mitigate the risk of the plant being introduced to their land. Core infestation area: Land managers should reduce impacts from the plant on priority assets. Land managers should mitigate the risk of the plant being introduced to their land. |
Greater Sydney
Exclusion zone: whole region excluding the core infestation area of Wollondilly and Camden |
Regional Recommended Measure*
Whole region: Land managers should mitigate the risk of new weeds being introduced to their land. The plant or parts of the plant should not be traded, carried, grown or released into the environment. Notify the Local Control Authority if found. Exclusion zone: The plant should be eradicated from the land and the land kept free of the plant. Core infestation: Land managers should mitigate spread from their land. |
Hunter |
Regional Recommended Measure*
Land managers should mitigate the risk of new weeds being introduced to their land. The plant should be eradicated from the land and the land kept free of the plant. The plant should not be bought, sold, grown, carried or released into the environment. Notify local control authority if found. |
Murray |
Regional Recommended Measure*
Land managers should mitigate the risk of new weeds being introduced to their land. The plant should be eradicated from the land and the land kept free of the plant. The plant should not be bought, sold, grown, carried or released into the environment. Notify local control authority if found. |
North West
An exclusion zone is established for all lands in the region, except the core infestation area comprising all Local Government Areas east of the Newell Highway |
Regional Recommended Measure*
Whole of region: The plant should not be bought, sold, grown, carried or released into the environment. Exclusion zone: Land managers should mitigate the risk of new weeds being introduced to their land; land managers should mitigate spread from their land; the plant should be eradicated from the land and the land kept free of the plant. Core infestation: Land managers reduce impacts from the plant on priority assets |
Northern Tablelands |
Regional Recommended Measure*
Land managers should mitigate the risk of new weeds being introduced to their land. Land managers should mitigate spread from their land. The plant should not be bought, sold, grown, carried or released into the environment. Notify local control authority if found. |
Riverina |
Regional Recommended Measure*
Land managers should mitigate the risk of the plant being introduced to their land. The plant should be eradicated from the land and the land kept free of the plant. |
South East
Core infestation: whole region except the exclusion zone of Shoalhaven, Eurobodalla, Kiama, Wollongong, Bega Valley and Shellharbour councils |
Regional Recommended Measure*
Whole region: Land managers should mitigate the risk of new weeds being introduced to their land. The plant should not be bought, sold, grown, carried or released into the environment. Exclusion zone: Land managers should mitigate spread from their land. Core area: Land managers reduce impacts from the plant on priority assets. |
*To see the Regional Strategic Weeds Management Plans containing demonstrated outcomes that fulfil the general biosecurity duty for this weed click here |
Reviewed 2019