Scientific name: Arctium minus, A. lappa
- Tall, many-branched, upright herb to 1.5 m high
- Large, hairy, triangular leaves (40 x 30 cm)
- Spiky, pink, thistle-like flower head about 3 cm long
- Flower heads in clusters at the ends of branches.
- A. minus has hollow-stalked leaves while the lower leaves of A. lappa are solid
- A. lappa has larger flower heads with longer stalks.
- Both species come from Europe/Asia and were introduced to New Zealand in the late 19th century.
- A. minus is occasionally found in waste places, roadsides, bush margins and sheep yards throughout both North and South Islands, except in Westland. Most abundant in Manawatu
- A. lappa is found in only a few locations in the lower South Island. Was present near Morrinsville in Waikato but now possibly eliminated from the North Island.
- Burdock is a biennial (living through two growing seasons) herb with new plants growing from seed
- Burdock has a large seed about 5 mm long and although it has a small pappus, it is too large for wind dispersal and relies on the hooked spikes on the seed head for its spread
- In the first year, plants form a rosette of large, hairy, triangular leaves, dying off to the root system during winter. In the second year, a tall branched flowering plant develops, that dies completely after fruiting.
- Young flowering stems and young shoots of burdock can be eaten
- The root is used in many herbal remedies where it is reputed to be one of the best cleansers, especially for skin ailments
Impacts on pasture
- Burdock is only a nuisance in poor, runout pastures or in scrubby, broken hill country
- When present in pasture, burdock will restrict grazing resulting in reduced pasture utilisation.
Impacts on forage crops
- As a biennial plant burdock is unlikely to be a persistent weed in annual forage crops. It is also unlikely to persist in perennial crops (e.g. lucerne) which are mown at least once a year.
Impacts on stock
- The burs are a major problem to sheep farming where they attach to the wool, causing problems with shearing and possibly rendering the fleece worthless.
Grazing and cultural management
- Young burdock plants may not survive intensive mob stocking but once established will not be grazed
- May be controlled by mowing although generally only found in low numbers and hand grubbing will be effective
- Burdock is reputed to indicate low pH and a requirement for lime.
- Burdock seedlings are readily controlled by the phenoxy herbicides MCPA and 2,4-D
- Larger plants controlled with the addition of picloram.
- Burdock is listed in some Regional Pest Management Strategies and it is an offence to knowingly move the plant or its seed into these regions. Look at the on-line RPMS for your regional council for more information.
- Holden, P 2020. New Zealand Novachem Agrichemical Manual. Agrimedia Ltd, Christchurch, New Zealand. 924 p.
- Popay I, Champion P and James T 2010. An illustrated guide to common weeds of New Zealand. New Zealand Plant Protection Society, Lincoln, New Zealand. 416 p.
- Dawson M, Navie S, James T, Heenan P, Champion, P 2007â€“2019. Weeds Key â€“ interactive key to the weed species of New Zealand (Accessed 20 July 2020).
- Auckland Council. Burdock. Arctium minus (accessed 20 July 2020)
- Douglas MH, Burgmans JL, Burton LC, Smallfield BM 1992. The production of Burdock (Arctium lappa L .) root in New Zealand – a preliminary study of a new vegetable. Proceedings Agronomy Society of New Zealand, 22: 67-70 (accessed July 20 2020).