Alligator weed discovered in Warragul and Cranbourne

19 December 2023

Landholders, horse and cattle owners in Warragul and Cranbourne are asked to keep watch for alligator weed, one of the world’s most invasive plants.

Agriculture Victoria Biosecurity Manager High Risk Invasive Plants Angela Constantine said recent detections in Warragul north and a previous one in Cranbourne have led to concerns there may be more in these areas.

‘Alligator weed is a State prohibited weed, the highest category of declared noxious weed in Victoria, invading both land and water and causing major blockages of waterways that impact agriculture and recreational activities,’ Ms Constantine said.

‘If you’ve seen alligator weed on your property, please report it and we will treat it at no charge – our Biosecurity Officers are trained to treat it without spreading the infestation further.’

Alligator weed has green, glossy, spear-shaped leaves and pink or green coloured hollow stems, with flowers similar to that on clover – ball-like, white, papery flowers on short stems.

Alligator weed grows roots readily from joints in the stem and can break off and form new infestations through mowing or slashing and flowing downstream in watercourses.

The grazing of alligator weed infested crops has been associated with increased sensitivity to the sun resulting in skin lesions, liver damage and death in cattle and lambs.

‘The alligator weed infestations may have come from fodder brought in from interstate, so even if it’s been some years since you’ve imported feed, please keep a careful watch,’ Ms Constantine said.

‘The discoveries come on top of infestations found on a rural property earlier this year, which is where the working theory has developed regarding imported feed.

‘We are now working to treat the infestations and checking if there’s been further spread in the area.’

Alligator weed has also been recorded growing in backyards in the past, so home gardeners should also keep watch.

If you see alligator weed, or any other State prohibited weed, please report it to the Agriculture Victoria Customer Contact Centre on 136 186 or email weed.spotters@agriculture.vic.gov.au.

For more information visit Agriculture Victoria's Alligator weed page.

Media contact: Maida Anderson

Phone: 0431 626 178