Cropping & Soil
1 March, 2026
Watch for parthenium weed in interstate fodder
FARMERS importing or receiving donated fodder from interstate following drought or the recent Victorian bushfires, are reminded to watch out for weeds growing from seeds contained in hay, particularly the state-prohibited weed, parthenium weed.
Agriculture Victoria biosecurity manager Angela Constantine said biosecurity threats like parthenium weed or parthenium hysterophorus can add pressure to already stressed systems.
“Parthenium is one of the world’s most aggressive weeds and a continuing threat to Victoria,” she said.
“It isn’t currently found in Victoria, but is present in New South Wales and Queensland, so the potential for it to invade Victoria is real.”
She said parthenium weed has several undesirable characteristics, not only is it difficult to control due to the large number of seeds produced by the plant’s fast reproductive cycle, but it’s also toxic to livestock.
It also inhibits other plant growth and can cause severe allergic reactions in humans.
“Farmers are asked to look out for the weed germinating in areas where imported fodder has been used,” Angela said.
“It can grow up to two metres tall, has deeply lobed leaves in a rosette and on the stem, with small white flowers up to one centimetre wide at the end of each branching stem.
“It can turn woody with age.”
She said that, where possible, feeding livestock in a contained area was an effective biosecurity practice to reduce the spread of weed seed across a property - but you should also monitor this area regularly.
“We encourage farmers to be particularly mindful when importing fodder from NSW and Queensland.
“Areas of Victoria along the Murray River, from Corowa, Cobram, Echuca to Swan Hill, are particularly at risk of invasion.”
Parthenium weed is most commonly spread by vehicles and farm machinery, so roadsides and farmland are at risk of invasion.
More information about identifying and reporting parthenium weed is available on the Agriculture Victoria website at https://go.vic.gov.au/455DEUs
If you think you have seen parthenium weed email weed.spotters@agriculture.vic.gov.au or call the customer service centre on 136 186.
Agriculture Victoria will remove all plants, for free.
A permit to import interstate fodder is required for fodder sourced from all states and territories (excluding Northern Territory and Tasmania).