Chilean Needle Grass (Nassella neesiana) is a perennial tussock-forming grass that grows in dense clumps, reaching over one metre tall and up to 1.5 metres when in seed. It is a serious agricultural weed and poses a significant threat to native grasslands.
It reduces pasture productivity by displacing desirable and palatable species. Once the plant enters its reproductive stage it becomes largely unpalatable, and its sharp seeds readily attach to livestock, particularly sheep. Seeds can damage wool quality and penetrate the skin, eyes and mouths of animals, sometimes burrowing into muscle and causing infection or ulceration.
It also out-competes native grasses, threatening remnant grasslands. Once established, it forms a persistent soil seedbank that can be difficult to manage.
Chilean Needle Grass is known to occur within Murrindindi Shire. Managing its spread requires a shared effort between landowners and Council.
Council actively works to contain and control Chilean Needle Grass on Council‑managed land, including selected roadsides, reserves and sections of the Great Victorian Rail Trail.
It is also present along main roads managed by the Department of Transport and Planning, such as the Goulburn Valley and Melba Highways.
Historically, Council has used spot‑spraying with glyphosate to treat infestations. While this approach reduces plant growth, it does not control the existing soil seedbank, meaning reinfestation can still occur.
To improve long‑term control, Council is trialling the use of flupropanate in combination with glyphosate. Flupropanate is registered for the control of Chilean Needle Grass and works by killing both the plant and its seedbank, reducing the likelihood of reinfestation.
Flupropanate is slow‑acting and is absorbed through plant roots. Visible plant death may take between three and twelve months, depending on seasonal conditions. Due to its long residual life in soil, flupropanate is applied sparingly as a targeted spot spray and used no more frequently than every two to three years to reduce the risk of ongoing residues and herbicide resistance.
Flupropanate has grazing withholding periods. Treated roadside and reserve areas are not intended to impact private landholdings; however, if you have concerns about moving stock via municipal roadsides, please contact Council to discuss your situation.
Landowners are encouraged to regularly check their properties for the presence of Chilean Needle Grass and act early if it is detected.
It produces three types of seed:
- Seeds on the seed head (panicle)
- Seeds within the stems
- Seeds at the base of the plant
Seeds can remain viable in the soil for many years and are spread primarily through vehicles, machinery and soil movement. Slashing is considered a high‑risk activity as it can distribute seed into uninfested areas. Seeds may also spread via water, fodder, livestock, wildlife and pets.
Landholders should carefully monitor paddocks following fodder purchases, particularly in spring or during drought conditions, as contaminated fodder is a common pathway for new infestations.
If you move stock between paddocks using roadsides, prevent grazing and lingering on roadside verges to reduce the risk of seed transfer. Grazing on roadsides or droving stock over longer distances may require a permit.
Early treatment of Chilean Needle Grass is critical to prevent long‑term establishment.
Chilean Needle Grass can look similar to native spear grasses (Austrostipa spp).
Key identifying features for Chilean Needle Grass include:
- Heavy seed heads that often cause stems to bend or droop
- Long, stiff awns attached to the seed, which are often twisted or kinked
- A sharp, pointed seed base (callus) that readily penetrates skin, wool and clothing
- When an awn is removed, seeds have a distinct corolla (ring) at the base, which helps distinguish them from Austrostipa species
Correct identification is important before undertaking any control works.
Chilean Needle Grass is a long‑lived perennial that reproduces entirely by seed. Germination generally occurs during autumn and winter, with plants forming tussocks that increase in size over time.
Seed production occurs in late spring and summer. Due to the multiple seed types and long‑lived soil seedbank, infestations can persist for many years if not actively managed.
Clean, uninfested areas should be carefully managed to prevent establishment.
Light or newly established infestations should be prioritised to prevent spread. Heavily infested areas may need to be managed progressively over several years.
Maintaining strong groundcover with competitive pasture species or native vegetation is one of the most effective long‑term management tools.
Prevention
- Avoid bringing contaminated fodder onto your property
- Clean vehicles, machinery and equipment after working in infested areas
- Monitor stock that have moved through known infestations
- Minimise soil disturbance where possible
Chemical Control
Only herbicides registered for control of Chilean Needle Grass should be used, and all label directions must be followed.
Spot treatment is preferred to minimise off‑target damage. Due to the plant’s biology and persistent seedbank, repeat treatments are often required.
Landholders considering chemical treatment may wish to seek professional advice or contact Council for guidance.
If you identify Chilean Needle Grass on your land or on Council‑managed property, please report it to Council’s Environmental Programs Unit.
More information is available on the Weeds Australia website.
For advice or questions about Council’s weed control program, contact the Environmental Programs Unit on (03) 5772 0333.