New Zealand weeds database
Find information on 77 of the more troublesome weeds found in New Zealand agriculture and horticulture.
This site is dedicated to informing people about weeds in New Zealand. It has been designed both for members of the public and for students looking for information on weeds.
This database provides information on 77 of the more troublesome weeds found in New Zealand agriculture and horticulture. With over 2000 weeds in New Zealand, we do not cover all species, but you will find many of the weeds that commonly cause problems in our pastures, crops, lawns and gardens.
Each page has information on how to identify the featured weed (with photos) as well as information about the weed and some suggestions on how best to control it.
Understanding herbicides short course
Learn how to control weeds using herbicides with Massey's 3-day short course on Understanding herbicides. There is also a university distance course available on Controlling weeds. If you are interested or would like more information, please contact Dr Kerry Harrington.
A – C
Annual poa is a small grass with light yellowish-green leaves.
Black nightshade grows berries when mature and has a purplish tinge on its stem and foliage.
Blackberry has hooks on its stem and grows red to black berries.
Bracken is the most invasive fern species in New Zealand.
Broad-leaved dock is a common New Zealand weed with wide leaves.
Broad-leaved fleabane starts as a rosette and then grows tall upright flower stems.
Broad-leaved plantain is a common perennial weed found in lawns and pastures.
Broom is a scrub weed that produces yellow flowers and seed pods similar to gorse.
Californian thistle is a common perennial thistle with an underground creeping root system.
Cape weed grows as a large rosette with yellow flowers.
Catsear is a perennial weed that grows as a rosette with an upright flower stem.
Chickweed scrambles along the ground, has little white flowers, and a single line of hairs on the stem.
Cleavers have foliage and fruits with tiny hooks that can cling to surfaces.
Clustered dock is a perennial weed with a large tap root system.
Couch is a rhizomatous grass that can cause problems in flower gardens and crops.
Creeping buttercup has three leaflets and produces shiny yellow flowers.
Creeping oxalis has three leaflets on each leaf and forms dense mats in lawns.
Creeping speedwell grows as dense mats in lawns and has lilac flowers.
D – H
Daisy grows as a rosette with white flowers and spoon-shaped leaves.
Dandelion grows as a rosette with upright flower stems topped with a yellow flower.
Fathen is a tall, upright and leafy weed that germinates only in spring or early summer.
Fiddle dock grows as a rosette and has leaves shaped like a fiddle.
Field speedwell has hairy leaves and grows small blue flowers.
Galinsoga is an upright annual weed that grows flowers with only five small white ray florets.
Giant buttercup grows in clumps and produces shiny yellow flowers.
Gorse is a scrub weed with sharp spine leaves and yellow flowers.
Great bindweed is a vine that produces heart-shaped leaves and large white flowers.
Groundsel grows throughout the year, producing wind-blown seeds.
Hairy buttercup produces shiny yellow flowers and has sepals below the flower petals that point downwards.
Hawkbit grows as a rosette with yellow flowers on wiry, unbranched stems.
Hawksbeard starts as a flat rosette then produces branched leafy stems with yellow flowers.
Hedge mustard has small yellow flowers and can grow more than one metre in height.
Hemlock is a poisonous weed that can grow over a metre in height with large white flower heads.
The hydrocotyle genus has 15 species with similar biology and control that are difficult to differentiate.
I – P
Ivy is a vine-like weed very commonly found in gardens.
Mallow genus has four common species in New Zealand.
Manuka is a native New Zealand scrub species with large numbers of small leaves.
Mouse-ear hawkweed has long hairs on its foliage and flower stems.
Musky storksbill starts life as a rosette, with each leaf made up of a series of leaflets.
Narrow-leaved plantain is a common perennial flat weed.
Nettle has jagged leaves with hairs that inflict a sting on your skin if you touch it.
Nodding thistle is a competitive thistle with a large seed head that tips over.
Onehunga weed is a small turf weed with finely divided leaves that produces prickles.
Oxeye daisy grows as a rosette and then produces long leafy flower stems.
Parsley dropwort is an invasive pasture weed with tubers on its roots.
Parsley piert is a small weed that grows commonly throughout New Zealand.
Paspalum is a grass weed with short stout rhizomes, joining weeds together to form dense clumps.
Pennyroyal has creeping stems and leaves that, when crushed, smell like mint.
Pink shamrock re-establishes from bulbs in spring and has very pale pink flowers.
R – S
Ragwort starts as a rosette, and when mature produces an upright stem with yellow flowers.
Red dead-nettle has jagged leaves and produces lilac flowers.
Redroot is a tall, upright weed that can grow over a metre in height.
Scarlet pimpernel grows along the ground and produces small orange flowers.
Scotch thistle is the most common thistle species in New Zealand with spines on both the leaf surface and margins.
Scrambling fumitory is a clambering annual weed that produces clusters of pink flowers.
Scrambling speedwell is a small annual weed that grows along the ground and produces blue flowers.
Selfheal has creeping stems and dark blue flowers.
Sheep's sorrel has arrow-shaped leaves and reddish upright flower stems.
Shepherd's purse starts as a rosette and then grows an upright flower stem with heart-shaped seed pods.
Sow thistle is an annual weed with a succulent stem when in flower.
Spurrey has sprawling stems with narrow leaves that grow in clusters along the stem.
Staggerweed is a small annual weed with lilac flowers and hairs on its square stem.
Stinking mayweed grows annually and has a very strong smell when crushed.
Suckling clover is a winter annual and is smaller than other clover species.
Sweet brier is a rose species with small pink flowers and spines down its stem.
T – Z
Tauhinu is a perennial scrub weed with small rounded leaves.
Tradescantia is a succulent, brittle weed that can easily break and fragment.
Turf speedwell is a small perennial weed that grows along the ground and produces white flowers.
Twin cress is a small weed, starting as a rosette and when mature sends out prostrate stems.
Water pepper has pale pink flowers, long leaves and fruits at the end of the stem.
White clover has a stolon system and its white flowers have clusters of many florets.
Wild radish has large seed pods and purple veins on pale yellow petals.
Wild turnip is a tall, annual, competitive weed with bristly leaves and yellow flowers.
Willow weed has leaves similar to a willow tree and grows clusters of small pink flowers.
Winged thistle establishes each autumn and has spines down the flower stem in spring.
Wireweed is a summer annual that is variable under different growing conditions.
Yarrow is a commonly found weed within pastures and has a deep rhizome system.
Associate Professor Kerry Harrington
+64 6 951 7814
- School of Agriculture and Environment
- College of Sciences
I am the weed science specialist at Massey University. As well as teaching aspects of weed biology, identification and control to undergraduate students, both in internal and distance learning papers, I also supervise a number of postgraduate students each year and undertake my own research.
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The Understanding herbicides short course is designed primarily as a stand-alone course to give participants a good grounding in the principles of using herbicides to control weeds.
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