Public needed for battle against pest plants
December 22, 2009.
Public needed for battle against pest plants this summer.
Environment Canterbury is asking Canterbury residents to look out for purple loosestrife and Chilean needle grass over summer and report any sightings to the Regional Council’s Potential Pest Line.
Environment Canterbury pest management committee chair Cr Eugenie Sage says that early detection and prevention is the best form of control for any pest plant, and while Environment Canterbury has undertaken extensive control programmes, public assistance is an important element to the council’s pest management success.
“Human spread can be prevented though good hygiene practices and by ensuring vehicles, machinery, equipment and other material is cleaned prior entering or leaving a property,” says Cr Sage. “Modifications including guards and fans can restrict the build up of seed on machinery, assisting in preventing the spread of these weeds, particularly along roadsides or vehicle tracks.”
Purple loosestrife is identifiable by its flowers that have five individual petals and by its square shaped stem. It is commonly found in damp places, such as wetlands and the banks of rivers and lakes, as well as gardens. It can block drainage and waterways and is spread by seed that is dispersed by water, wind, birds and humans.
“Since 2003, Environment Canterbury, the Department of Conservation and the Christchurch City Council have worked together to curb the spread of purple loosestrife within the region,” says Cr Sage. “Over this period, the density of infestations at known sites has reduced considerably with a number of home garden and dry sites eradicated as well. While the density of infestation in wet areas has been reduced, ongoing control efforts are required to reach our goal of full eradication.”
Environment Canterbury is also undertaking control work at the only known Chilean needle grass site in the region, located at Cheviot, North Canterbury. The programme involves a combination of spraying and grubbing with control at the site expected to be completed before Christmas this year.
“Environment Canterbury’s northern area biosecurity officers are also implementing a search program in the vicinity of the known site,” says Cr Sage. “We are encouraging members of the farming community and public to keep a look out for Chilean needle grass with its distinctive seed head now in flower.”
The plant is typically found growing in dry grassland areas, and because it grows prolifically, it can displace pasture and native vegetation. Chilean needle grass is unpalatable to stock when in seed and its long, sharp seeds can injure the skin and eyes of stock, downgrading/devaluing fleeces and animal carcasses.
Canterbury residents are advised to report sightings of either purple loosestrife or Chilean needle grass on Environment Canterbury’s Potential Pest Line on (03) 363 9380. Residents are asked not to bring samples for identification as this may increase the risk of spread of the plants. Information is available online at http://ecan.govt.nz/advice/your-land/plant-animal-pests/.