'NO MOW' signs mark fight against pest plant

26 November 2010

Napier residents may wonder if their Council is failing to keep the City beautiful this summer, with around 25 grassland areas being fenced off and left unmown.

Darin Underhill, Hawke’s Bay Regional Council (HBRC) Biosecurity Team Leader - Plant Pests, says with the assistance of Napier City Council ‘No mow’ signs recently placed beside some Napier river banks and streams are part of an ongoing joint HBRC and MAF Biosecurity New Zealand (MAFBNZ) programme to eradicate the pest plant phragmites (Phragmites australis).

A giant grass capable of invading wetlands and water margins, crowding out native plants and destroying native birds’ habitats, phragmites’ roots are strong enough to penetrate concrete. They can easily reach into stop-banks, causing slumping and blocked drains.

Mr Underhill says the plants will be left to grow to 600–800mm in height and then hand-sprayed with Unimaz herbicide, used successfully over the last decade to control phragmites. It was likely phragmities became established after root fragments were spread by mowing or other machinery.

MAFBNZ Pest Management Group Senior Advisor, Victoria Lamb, says phragmites is an Unwanted Organism under the Biosecurity Act, meaning it could not be sold, bred or spread.

While New Zealand has a world class biosecurity system and more than 2400 plant pests were stopped by MAFBNZ at, or just after, the border in 2009, unwanted plants and pests could significantly impact our economy, environment and human health.

“Biosecurity is a collaborative effort, and everyone has a role to play in keeping out unwanted pests and diseases and containing, or wherever possible, eradicating those that establish here,” Ms Lamb said.

Mr Underhill said the HBRC and MAFBNZ would control phragmities plants found in private gardens at no cost to landowners.

“If you see plants you think might be phragmites, let the Hawke’s Bay Regional Council know by ringing the freephone 0800 108 838,” he said.

For further information and phragmites images contact:
Susan Wylie, Communications co-ordinator, HBRC, (T) 06 833 9208. susan@hbrc.govt.nz
Or Helen Corrigan, Senior Adviser, MAFBNZ Helen.corrigan@maf.govt.nz (M) 029-894 0687. www.maf.govt.nz