Nettle

Urtica urens

Nettle (Urtica urens) is present New Zealand wide except for Northland, Taranaki and Westland. It is well known as stinging nettle due its characteristic of causing swelling and stinging to the skin upon contact. The erect 60 cm tall annual is often found on farms in stock camps where it needs bare ground to germinate. Animals will not graze it. Nettle can also be a troublesome weed in cropping and horticulture.

Commonly called stinging nettle (Urtica urens) due to its leaves with stinging hairs on its leaves, which when brushed against cause a painful rash on human skin. Nettle is found throughout New Zealand especially in cropping areas and in pasture where it is not grazed by stock. Nettle can be a challenging weed in fodder beet crops as it is only susceptible to post-emergence herbicides as a seedling (3-4 leaf stage).

Cotyledons:

Round with slightly notched apex
Base rounded
Shortly stalked

Leaves:

Oval
Strongly toothed with stinging prickles

Mature plants grow to 60 cm tall . Leaves are dark green, in opposite pairs on the stem and covered in stinging bristles. Inconspicuous green flowers arise from leaf axils.

Related Pests

Californian Thistle

Cirsium arvense

Californian thistles (Cirsium arvense) are a perennial thistle that is a major weed of pastures and crops throughout New Zealand. It grows and spreads in patches with a spreading underground root system. In the winter the foliage dies off from frosts with new plants growing from the underground root system in the spring. The root system is easily broken up by cultivation but new plants originate from these and can be very problematic in crops and new pastures.

Broad-leaved Fleabane

Conyza sumatrensis

Broad-leaved fleabane (Conyza sumatrensis) is an annual or biennial weed that is common throughout New Zealand on roadsides, wasteland, orchards and vineyards. In recent years it has been increasingly seen in pasture. It starts as a rosette that then forms a vigorous upright stem up to 1.8 metres tall. The stem branches at the top producing copious quantities of small green seed heads.

Field Pansy

Viola arvensis

Field pansy (Viola arvensis) resembling the garden variety pansy, the field pansy grows year round in parts of the North Island, but more commonly in the South Island. It grows in planted paddocks, on waste land and road-sides. Its seeds are similar to those of some forage seed crops making separation of seeds problematic. The plant grows close to the ground when young; when older stems can grow upwards to about 30 cm. The flowers are small, with five petals – two upper petals with a tinge of blue/violet, and the lower three petals pale yellow. Oval shaped mid green coloured leaves in a rosette formation have a shallow toothed edge. Seeds are light brown, oblong and approx. 1.5 mm long, encased in an oval pod.

Henbit

Lamium amplexicaule

Henbit (Lamium amplexicaule) is a purple-flowered weed that is commonly present in cropping areas in the South island. It is a slender annual that grows to 30 cm tall with purple whorl shaped flowers.