Horizons brings in tiny gall mite to eat weedy introduced broom

Landowners with weedy introduced broom infesting their pasture are being offered gall mite infested bundles to help fight against it.

Horizons Regional Council's pest plant co-ordinator Craig Davey says broom is a major problem within the Manawatū-Whanganui Region, and is chronic for overtaking pasture growth.

"Broom gets a foothold in untended areas and biological control is best for those not easily sprayed, such as steeper hill country or retired areas you'd rather not let fill up with broom."

The broom gall mite is microscopic and eats only broom. The council has bundles of broom that have been infested available to provide to landowners. The mites have been in this region for six years, and are doing their job "exceptionally well", Davey said.

"These mites create big ugly galls, or growths, on the plant which stunts growth and eventually kills it. This is due to the plant sending all of its energy into fighting the galls instead of actually growing."

Horizons staff will be at six locations around the region on December 18, from 8am until 1pm, for farmers or urban landowners to receive the 'Christmas galls'.

"Not only will tying these infested broom plants to healthy broom branches help to eventually kill them off, the gall mites will struggle to locate from plant to plant. By moving them around manually we're making gains in the long term, as they'll be covering a wider area," Davey said.

Horizons has a limited number of bundles, and it will be first in, first served. Anyone who misses out will have an opportunity to get bundles later next year, and will be put on a waiting list.

On December 18 the galls will be at the Horizons offices in Taumarunui, Whanganui, Marton, Woodville and Taihape, and at The Big Carrot in Ōhakune.