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

  • Erect biennial plant, forming a rosette in the first year, from which tall, square stems grow in the second year
  • Plants flower from October to April
  • The flowering stem can be up to 2 m tall, and is very stiff and rigid, with bristly hairs on the ridges
  • The large, egg-shaped flower head is erect and prickly and looks like a thistle flower when young. Florets are pinkish to purple
  • After seed has been shed, the tall dead stems can remain standing for several months
  • Wild teasel is now found in drier parts of New Zealand throughout both islands.

Origin

  • Wild teasel was originally found in south, west and central Europe and in Asia as far east as Iran
  • Commonly found in drier parts of New Zealand, where it can be seen on roadsides, in abandoned pasture, on cultivated land, and in river beds and waste areas
  • First recorded in this country in 1878, and may have been used as a commercial crop before then
  • Cultivated teasel was used in the wool industry for ‘carding’, aligning the fibres, and also for aligning and raising the nap on fabrics
  • Dried seed heads are common in dried flower decorations.

Life cycle

  • Seeds germinate in gaps in vegetation, mostly in autumn and spring
  • Teasel plants produce a rosette in the first year from which a tall flower stalk grows in the second year. The plants die after flowering
  • Plants have deep tap roots.

Impact on pasture

  • Teasels do not seem to grow in regularly grazed and well-maintained pasture and are commonly restricted to poor pasture, waste places and roadsides. In poorly maintained pasture, though, they could replace more useful species.

Impact on livestock

  • Teasel probably has little effect on livestock since it is not often found in high-producing pasture. In less well maintained pasture it could limit the availability of more useful pasture species.

Pasture species/cultivars

  • Dense, vigorous pastures help stop wild teasel and other weedy species from establishing and reduce their growth and survival
  • Grass species or cultivars appropriate to the district and infected with the right endophytes should help
  • In areas where cocksfoot grows well it could be a better competitor than ryegrass.

Chemical control

Chemical control of wild teasel is rarely warranted as it tends to grow along roadsides and is not often found in pastures. In the unlikely event that chemical control is required, wild teasel is susceptible to 2,4-D and other herbicides commonly used for broadleaf weed control in pastures. These are probably more effective on young plants in the rosette stage.

References

  • Popay I, Champion P, James T 2010. An illustrated guide to common weeds of New Zealand. New Zealand Plant Protection Society, Christchurch, New Zealand. 416 p.