Nasella tussock

Common name:  Nasella tussock
Scientific name:  Nassella trichotoma
Management programme:  Progressive containment

North Otago whānau - we need your help!

North Otago covers a huge area, so we really need the public’s help with this one. If you have seen nassella tussock anywhere in the region, email biosecurity@orc.govt.nz or call 0800 474 082

 

Have you seen Nassella tussock?

Nassella tussock is around one metre tall with fibrous roots and small, oval seeds. It displaces other grasses, leaving pasture unpalatable to stock – its drought resistant and dense infestations can cover hectares of productive land.

What does it look like?

It is a tufted, tussock grass with a swollen stem. Its fine, tightly rolled, light green or yellowish-green leaves feel needle-like and very tough. It flowers with purple-pink flowers during the November-December period and each mature plant can produce up to 100,000 seeds each year. Roots are deep, matted and fibre-like. It can be hard to tell the difference between Nassella tussock and other tussocks, but a good way to test the difference is by running your fingers down the leaves, if the texture is rough it’s probably Nassella tussock.

Duntroon, Kurow and Otematata have been the locations of several new and significant Nassella infestations recently and ORC’s biosecurity team are growing concerned that there could be a significant outbreak. We’re appealing to landowners, stock agents and those in the agricultural industry to keep an eye out for signs of nassella on rural properties. 

North Otago covers a huge area, so we really need the public’s help with this one.

If you have seen nassella tussock anywhere in the region:
email 
biosecurity@orc.govt.nz or
call 0800 474 082

 

Flower/seed heads are drooping and purplish, occurring mid-spring to mid-summer

 

 

Stem bases are swollen, hard, and look like small shallots.

 

Why is it a pest?

Nassella tussock affects production values by reducing pasture quality and it also affects environmental values by displacing native species in tussock grassland. So far, nassella tussock has only been found in the Roxburgh, Alexandra, Cardrona and Waitaki Valley areas.

What does it look like?

Nassella tussock looks other tussock grass. It is a tufted, tussock grass with a swollen stem. Its fine, tightly rolled, light green or yellowish-green leaves feel needle-like and very tough. The plants stand up straight when young but start drooping with age and grow up to 70cm high and 80cm wide. It flowers in October and has a purplish tinge. Each mature plant can produce up to 100,000 seeds each year. Roots are deep, matted and fibre-like. It can be hard to tell the difference between nassella tussock and other tussocks a good way to test the difference is by running your fingers down the leaves; if the texture is rough it’s probably nassella tussock.

What are the rules?

Everyone in Otago must eliminate nassella tussock on the land that they occupy.

Please let us know if you’ve spotted nassella tussock by calling ORC on 0800 474 or emailing biosecurity@orc.govt.nz.            

How can I control it?

For low numbers the best control method is to grub the plant out, removing soil from the roots and leaving the plant to rot down. You can spray thicker infestations; get in touch with our biosecurity team at biosecurity@orc.govt.nz for advice on this.

Management programme