thisNZlife

Pasture Watch

A real stinger

Why are they weeds?

Compete with pasture, crops, and garden plants

Where are they found?

Nationwide

Are they toxic?

No, but the leaves will sting you

Other things to know

Can be eaten, used in herbal medicines, food sources for some caterpillar species

MY JOB isn’t normally painful. But last year, a walk through a paddock of lucerne turned into an eye-watering experience. It was infested with annual nettles (Urtica urens) and I was stung up my legs.

There are several species of nettle common in temperate areas of NZ. They’re rarer in Northland, Taranaki, and on the West Coast.

Annual nettles can go to seed at any time, dropping large numbers of small brown seeds. These germinate in spring and autumn. Perennial nettles (Urtica dioica) keep growing thanks to their invasive roots.

People have used the plant for hundreds of years (see box at right), but livestock know to stay away. The leaves release toxic histamines and acetylcholine when touched, which causes stinging, itching, and redness to the skin. This means nettles can become invasive, reducing pasture quality and utilisation.

How to control nettles

You can pull plants by hand but always wear long gloves.

Herbicides containing flumetsulam or MCPA work well on small seedlings. When the plants get bigger (or you want to control perennial nettle), the most effective spray contains triclopyr (ie, Tordon™ PastureBoss or Tordon™ Brushkiller).

CONTENTS

en-nz

2021-08-01T07:00:00.0000000Z

2021-08-01T07:00:00.0000000Z

https://thisnzlife.pressreader.com/article/282402697366725

NZ Lifestyle Magazine Group