Burdock

Scientific name: Arctium minus, A. lappa

Arctium minus

Arctium minus

Arctium minus

Arctium minus

Arctium minus

Arctium minus
  • Key characteristics
  • Biology
  • Impacts
  • Control
  • Further information

  • 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.

Diagnostic differences

  • A. minus has hollow-stalked leaves while the lower leaves of A. lappa are solid
  • A. lappa has larger flower heads with longer stalks.

Origin

  • Both species come from Europe/Asia and were introduced to New Zealand in the late 19th century.

Occurence

  • 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.

Life cycle

  • 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.

Benefits

  • 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.

Chemical control

  • Burdock seedlings are readily controlled by the phenoxy herbicides MCPA and 2,4-D
  • Larger plants controlled with the addition of picloram.

Biosecurity

  • 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.