Council takes hard line on soft pest

Horizons Regional Council is starting its first weed-busting campaign in Wanganui with a soft target - but a nasty one.

The council is gunning for woolly nightshade, also known as tobacco weed and Solanum mauritianium.

The South American shrub is becoming a major plant pest north of Taupo, and is common in Taranaki.

Horizons staff aim to remove it from the city, as part of the new Wanganui Urban Weed Programme. It has run a similar weedbuster campaign in Palmerston North, against old man's beard/Clematis vitalba.

Horizons environmental management officer Neil Gallagher said taking on old man's beard in Wanganui would be a mammoth task.

"With woolly nightshade, we know that we can deal with it. We don't want to see in Wanganui what you see when you fly into Auckland airport - you see gullies full of a light grey plant. It's everywhere."

Woolly nightshade can grow into a tree taller than a house in two or three years. It has large, soft, light-green leaves that are covered with grey hairs, small purple flowers and green and yellow berries.

"The tiny hairs covering the plant can cause asthma-like symptoms and all parts of the plant are poisonous and stink like kerosene," Mr Gallagher said.

The plant is poisonous to young stock, and its seeds are spread far and wide by birds. Its shed leaves lie thick on the ground, preventing other seedlings from growing.

In January Horizons released a Brazilian lace bug species on to plants in a Kukuta gully. If that population grows the bugs will completely strip plants - but it is early days yet.

In the meantime, Wanganui people can help by digging woolly nightshade out of their gardens or cutting the trunk near the base and covering the cut with herbicide.

Horizons officers are available to help get rid of the plants, and also give advice on other weeds. Their woolly nightshade campaign will go until Christmas and they can be contacted on 0508 800 800.