Nassella tussock not just a northern issue
Dense nassella infestations have been found near Duntroon and Kurow. Some of the plants are estimated to be 30 years old. Find out about the pest and what you can do to prevent the spread through south Waitaha Canterbury.
Nassella tussock isn’t a new invasive pest plant. It’s been present in Aotearoa New Zealand since 1860 arriving from South America and has been under management since 1940.
Nassella became the only pest plant to have a dedicated act in 1946 when the Nassella Tussock Act became law.
Historically, the invasive grass nassella tussock has been considered a north Canterbury issue – with some farming communities grubbing the pest plant since the 1960s.
Our team have undertaken extensive searches in neighbouring properties, increased surveillance on susceptible land and has been following leads on hay movements in the Duntroon area during the 1970s - a possible pathway for nassella to spread to the south.
However, there is a lot of land to cover, so we encourage landowners to learn more about what nassella looks like and to keep an eye out on their properties.
Identify and report nassella tussock
Nassella can be tricky to identify and is often confused with native tussock species. It’s easiest to identify when flowering.
Look out for:
- purplish flowerheads with flowering stems growing up to one metre tall
- swollen stem bases just above ground level and shallot-like
- bright green leaves are thin and rough when rubbed from tip to base.
If you think you might have nassella on your property, getting on top of it early is essential as each mature plant can produce up to over 14,000 seeds. It easily spreads on wind, water, stock, clothing and machinery, quickly impacting neighbouring blocks or communities.
Learn how to identify, report and control this invasive grass that is spreading in south Canterbury.
Nassella tussock stem bases
Impacts of nassella tussock
Nassella favours north-facing hillsides and/or free-draining soils where dry conditions open up each year, and the lack of competition from other species allows nassella to thrive.
The plant can dominate low-producing grassland and outcompete valuable pasture species. The leaves are also unpalatable and indigestible which can cause sheep to lose their general good health condition in densely infested areas.
Have you seen any suspected nassella tussock plants on your property? Report any sightings via our online form. For assistance and advice on controlling this pest, email us biosecurity@ecan.govt.nz or call 0800 324 636.