Three invasive weeds that have the potential to devastate SA's agriculture and native ecosystems have been located in backyards across the state.
The recently detected weeds at Naracoorte, Aldinga, Clarendon, Hayborough, Port Elliot and Adelaide are not yet established but the weeds still pose a serious threat and are required by law to be reported.
These detections follow the release of a Centre for Invasive Species Solutions report into the annual costs of weeds in Australia, which totalled almost $5 billion across Australia.
Serrated tussock, Nassella trichotoma, was found in a Naracoorte garden and considered Australia's worst pasture weed, and also dominates native grasslands.
It costs $50 million annually in lost production and control costs and is also a fire hazard.
Mexican feathergrass, Nassella tenuissima, found in gardens in gardens south of the state and has similar impacts to serrated tussock.
Horsetails, Equisetum spp, was found in a number of gardens in Adelaide, it is toxic to livestock and highly invasive.
Biosecurity SA strategy, policy and invasive species general manager John Virtue said the common thread between the three weeds was that they were grown in people's backyards.
"These people thought they were growing an ornamental or native plant - they had no idea they were growing a highly invasive weed," he said.
"Our concern is to stop these weeds from being grown and eventually becoming established in SA, but we need the cooperation of everyone, particularly the gardening community.
"There is a history of people inadvertently introducing plant species into their gardens which are interesting or attractive, without realising the impact they could have if they spread into the environment."
Dr Virtue said serrated tussock and Mexican feathergrass looked very similar to some of SA's native grasses.
"If people are growing these sorts of plants in the backyard and don't know exactly what they are, take the time to make sure they are identified," he said.
"Horsetails had been grown as pot plants, but if even a small amount of this was to establish in our natural wetlands and watercourses it would be extremely difficult to control."
All three of these plants are illegal to grow, distribute or sell in SA.
If you think you may have found one of these species, contact your local Natural Resources office or Biosecurity SA on 8303 9620, who can help identify, remove and dispose of them.
