American skunk-cabbage

Common Name

  • American skunk-cabbage

Latin Name

  • Lysichiton americanus

What’s the problem?

  • American skunk-cabbage is a non-native species which can out compete native plants in damp habitats such as wet woodland, pond margins and stream banks.
  • The plant can quickly spread via seed transported by watercourses, birds and mammals.

Legal Implications?

  • American skunk-cabbage is listed under The EU regulation on Invasive Alien Species. To control this species, it is now banned from sale, growing, cultivating or releasing into the wild. The control of this species applies to individuals and businesses however transitionary measures allow businesses to continue selling stock for a further year.
  • This species is not currently Listed as a Schedule 9 species under the Wildlife and Countryside Act 1981, although there are calls for it to be added.

Images supplied by GBNNSS

In Detail

  • American skunk-cabbage is native toWestern North America and was introduced to the UK as anornamental bog plant.
  • The flowers produce a strong fragrance that resembles that produced by skunk, giving it its common name.
  • The plant requires wet conditions to thrive but has no specific soil requirements and will grow well on most wet sites.
  • Once established the plant is very invasive, forming dense colonies which can spread by rhizome and by seed, spread by water currents, by birds and mammals.

Identification

  • Clump forming robust herbaceous perennial with large, leathery like lance-shaped green leaves which can grow to 1.5m in height. Leaves form after the club like flower.
  • The plant flowers March – May. Flowers spikes are bright yellow and reach 40cm in height producing skunk like scent which attracts pollinators.
  • The plant is spread by rhizome and by seed. Rhizome measure 30cm in length and can be 2.5- 5cm in diameter. Seeds are contained in green berry like fruit.
  • Leaves die down over winter leaving bare soils, growing back in spring.
  • Species can be mistaken for Lords-and-Ladies (native species) and for Asian skunk-cabbage (non-native species).

Control Methods

Mechanical:

  • Plants, new seedlings and rhizomes can be dug out and removed from site for disposal. However, if fragments of rhizome remain, these can regenerate and form new plants with the potential of spreading the infestation further.

Chemical:

  • The leaves can be effectively treated with herbicide however there are limitations in what herbicides can be used near water courses.
  • Applications should be made June - October when the leaves are fully grown and when ground conditions are drier. Multiple applications may be required each growing season.

The use of herbicides near watercourses requires AqHerb01 approval from the Environment Agency.

If you have concerns over American skunk-cabbage species on your land, if you are unsure of your legal responsibilities, or, if you would like a quotation for control, please contact one of our specialist surveyors. Treatment costs start at £380.00 + VAT.