Waikato Regional Council is moving to contain and eradicate a significant outbreak of alligator weed which has been discovered on a 36-hectare property just south of Hamilton.
Alligator weed, which has been in the country for more than a century, is a South American pest plant that is fortunately rare in the Waikato. The weed can spread rapidly, taking over pasture and other land, and is very difficult to eradicate.
The council classifies alligator weed as an “eradication” pest, meaning that where it is detected the council will act to remove it immediately given the threat it poses to productive land and native plants, said biosecurity officer Wendy Mead.
“The weed is spread extensively in patches over the 36-hectare property near Hamilton and we are getting on to its control promptly,” said Mrs Mead.
“We will use a range of herbicides, to be applied by registered spray contractors under our supervision, in an effort to contain and eradicate it as soon as possible.
“It is likely to take some years to completely eradicate given that alligator weed outbreaks are hard to kill off quickly.”
Costs of removal – expected to be several thousand dollars - will be met by the council.
The movement of soil and plant matter from the property will be restricted as part of measures to stop the spread of the weed. The property owners, who are fully supportive of the control programme, are co-operating with the council’s control efforts, Mrs Mead said.
The presence of alligator weed was discovered recently during a routine inspection by a council pest plant contractor. It is not certain how the alligator weed ended up taking hold on the property. However, it appears likely to have been transported onto the site through contaminated soil.
Mrs Mead said the discovery was a reminder for all property owners around the region to be vigilant about the presence of noxious weeds. “It is timely, with the current dry conditions, to remind farmers to check stock food for weeds and be wary of importing feed from unknown sources. We advise farmers to always insist all stock food, sand or soil and machinery that enters their property is weed free.
“We are happy to identify pest plants and give advice on weeds wherever people have concerns,” said Mrs Mead.
“It’s important for the sake of our rural economy and environment to keep on top of such pests as alligator weed given their destructive potential.”