Just like its reptilian namesake, Alligator weed lurks in shallow waters and riverbanks waiting for its chance to strike.
As a State Priority and Weed of National Significance, a Biosecurity Zone is in place for the North Coast region meaning all Alligator weed infestations must be eradicated where possible. It is illegal to sell or trade Alligator weed.
Insidious weed
Alligator weed (Alternanthera philoxeroides) is a creeping, herbaceous plant with long hollow stems. It may grow around 50cm high on land and water, although stems on land are usually thinner and more upright. It has shiny green, spear-shaped leaves around 5cm long which are opposite each other along the stem. Round, white flower heads grow on a stalk rising from the leaf junctions.
Alligator weed is not confirmed to produce viable seeds in Australia, but spreads readily via fragments. The dumping of green waste, poor control attempts and movement of infected soil are the main methods of Alligator weed spread.
Alligator weed a challenge to remove
Alligator weed devastates biodiversity in riparian areas, disrupts floodplain agriculture, water infrastructure, fishing and recreation. Deep roots extend over a metre into the soil allowing it to survive all conditions. This also makes both physical and chemical control methods very difficult to implement successfully.
Report sighting for support before removal
Residents are encouraged to report any suspected infestations of Alligator weed to the Biosecurity officer, and not to attempt control until confirmed. Control must be thorough and precise otherwise it is likely to make the infestation worse. Refer to NSW WeedWise for further information NSW WeedWise and contact Council.
