Woolly mullein

Scientific name: Verbascum thapsus

Woolly Mullein plant

Woolly Mullein rosette

Woolly mullein rosette

Woolly Mullein Plant

Woolly Mullein plant

Woolly Mullein plant

Woolly Mullein flower
  • Key characteristics
  • Biology
  • Impacts
  • Control
  • Further information

  • A distinctive weed of waste places, roadsides and in pastures. Common in drier eastern areas
  • The often large rosette is made up of large, thick, silvery-grey woolly leaves
  • In the second year a tall, erect flowering stem, up to 1 m tall, grows from the centre of the rosette, and carries a spike of yellow flowers, each up to 30 mm across
  • Individual flowers are yellow, with 5 petals
  • Plants flower from July to April
  • After seed has been shed, the tall dead stems can remain standing for several months.

Similar weeds

  • Other species of the Verbascum genus are found in New Zealand:
    • Verbascum virgatum (moth mullein) has green leaves, not woolly hairy, with short hairs restricted mainly to the midrib. It has larger yellow flowers, up to 40 mm in diameter and is found in open disturbed places throughout New Zealand
    • Verbascum creticum (Cretan mullein) is very similar to moth mullein but the calyx lobes at the base of the flower, are serrated. This species is mostly found north of Hamilton
    • Verbascum blattaria (white mullein) is similar to woolly mullein but is less woolly and has white flowers. It is mostly found in the Auckland area but has also been found as far north as Mangonui and occasionally as far south as the Wairarapa.

 

Origin

  • Woolly mullein was originally found in Europe and in western Asia
  • In New Zealand it is now found in drier, eastern areas of both islands, mostly along roadsides and in dry, stony places
  • It was first recorded in this country in 1864, probably introduced as a garden plant.

Life cycle

  • Seeds mostly germinate in open areas in autumn and spring
  • Plants produce a large rosette, up to 600 mm across, in the first year and from this rosette a tall flower stalk grows in the second year
  • Flowers mature along the flower stem, those at the base first. They open in the morning and close by mid-afternoon
  • Flower stalks die after flowering but the dry stalks can remain standing for months.

Benefits

  • The Greeks and Romans are said to have used the stems and leaves as lamps or torches, and the seeds as a fish poison. The flowers have been used to produce a yellow dye. The plants also have pagan significance and for this reason their growth was banned by the early Christian church
  • Historically plant material was used medicinally as a cure for gout, toothache, warts, diarrhoea, stomach cramps, chest pains, coughs and asthma.

Impact on pasture

  • Mulleins do not grow in regularly grazed and well-maintained pasture and are commonly restricted to poor pasture, open and waste places and roadsides
  • Commonly found on sunny hillsides with light, volcanic soils
  • In poorly maintained pasture, they could replace more useful species.

Impact on livestock

  • Woolly mullein is avoided by stock (it would be like eating carpet!) but is said to irritate animals that try it.

Pasture species/cultivars

  • Pasture improvement, where possible, is the best way of controlling woolly mullein. Dense, vigorous pastures help stop this and other weedy species from establishing and also 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 woolly mullein is rarely warranted as it tends to grow in poor pasture and along roadsides. In the unlikely event that chemical control is warranted, woolly mullein is susceptible to triclopyr/aminopyralid (Tordon® Pastureboss) and to glyphosate but the latter will also destroy any nearby green plants of any kind.

  • Parsons WT, Cuthbertson EG 1992. Noxious weeds of Australia. Inkata Press, Melbourne and Sydney. 692 p.
  • 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.