Weeds

Ragwort

Ragwort is a very difficult weed to control and spreads easily. It grows all year round and is established from both seeds and old existing roots. Ragwort is a poisonous plant to stock and becomes more palatable when sprayed, so stock must be kept away until it has died down.

Dandelion

Dandelion is often a problem in many pastures. Effective control is only possible during the seedling stage because the plant is both deep rooted and perennial. Taproot re-growth is poorly controlled. In new pastures, spray early before the taproot becomes established.

Nettles aka Stinging Nettle

Nettles are fast-growing, and can quickly choke out new grass and clover. Herbicides applied at the seedling to small plant stage is a very effective method of control. Higher rates at larger growth stages will only suppress the plant, not kill it, so early application is best.

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Thorn Apple

Thorn apple can be a tall erect plant with long, smooth, toothed leaves about 8 to 20 cm long. The upper surface of the leaves is a darker green, and the bottom is a light green.

A very difficult weed to control late, best controlled as a small seedling.

Canadian fleabane

Prolific and fast growing, it prefers light soils and can withstand dry conditions. Fleabane produces a large number of seeds which can germinate in both spring and autumn.

Spray at seedling to small rosette stage.

Willow weed

Willow weed is a sprawling summer annual found in moist, well-aerated soils. Highly invasive, it can smother large areas of both newly-sown and established pastures. It is generally unpalatable to stock, but deaths have been recorded overseas. Willow weed produces a large volume of seeds which remain viable for some time, and it can also reproduce from small pieces of broken stem.

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Oxeye Daisy

A perennial weed that becomes more prominent in spring. Often found in open pastures and on sideings. A very difficult weed to control. Find out more

Cornbind

Black Bindweed, Greater Bindweed, Field bindweed, Convolvulus and Cornbind are long clambering vines. Their large trumpet flower and heart shaped leaves are a common site in gardens, waste areas and along roads.

Autumn is the best time to spray bindweed foliage initially, but it is important to then re-spray any regrowth in spring.

Black Nightshade

Black nightshade is common in lowland cultivated habitats in NZ. It is typically less than 75cm tall, and often found in crops and gardens. It belongs to the same Solanum family as tomatoes, eggplands, capsciums and potatoes.

Amaranthus

There are a number of different species of Amaranthus in NZ. They tolerate drier, warmer conditions than many other weeds, making them problem weeds in Maize and other summer crops.

They typically germinate in late spring, flowering in summer. Most found in NZ are annuals, and die in the first winter frosts.

Buttercup

Most common in dairy pastures, particularly on less free draining soil types. Creeping and giant buttercup can be particularly invasive and are not easy to control. May require two applications in the spring to ensure adequate control. Find out more

Fathen

Fathen is an extremely fast-growing weed with excellent survival mechanisms. In good conditions it can grow up to 1m high before flowering, but in dry situations it will flower and produce seed before it is 4cm high. It also has a very thick waxy layer which coats the leaves in dry weather. This is designed to hold moisture in the plant, but it is equally effective at preventing absorption of herbicides. Fathen can grow densely in spring-sown pastures. Spraying pre-flowering gives the most effective control.