Skunk cabbage: Physical removal

How is the evidence assessed?
  • Effectiveness
    65%
  • Certainty
    55%
  • Harms
    not assessed

Source countries

Key messages

  • A study in Switzerland found that annual physical removal of recently established skunk cabbage plants over five years removed the entire stock.
  • A study in the Netherlands found that manual removal of mature skunk cabbage plants was effective for a small outbreak of a small-growing plant.
  • A study in Germany reported that after the first four years of a twice yearly full removal programme of skunk cabbage, a large number of plants still needed to be removed each year.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A study in 2003-2008 in Switzerland (Buholzer pers. comm. (2009) In European and Mediterranean Plant Protection Organization 2009) found that annual physical removal of recently established skunk cabbage Lysichiton americanus plants over five years removed the entire stock. One hundred plants were removed in 2003, compared with 20 plants in 2004, and only a few individual plants in each of 2007 and 2008.  In 2007 and 2008, no more plants had germinated.  From 2003 to 2006, two people removed the plants by hand on an annual basis following which a monitoring programme was put in place to check for regrowth every second year.  Total costs to 2009 were reportedly around €1000, declining from €500 in 2003, to just monitoring costs from 2008 onwards.

    Study and other actions tested
  2. A study in 2005-2008 in the Netherlands (Rotteveel 2007) found that manual removal of mature skunk cabbage Lysichiton americanus was effective for a small outbreak of a small-growing plant.  In 2008, two plants of over one year old, and dozens of new seedlings were found and subsequently removed by volunteers.  This followed an annual inspection and removal programme which started in December 2005.  Following removal, skunk cabbage plants were dug up, and then buried deep in the ground.  No further information was available.

    Study and other actions tested
  3. A study in 2004-2008 in the Taunus region in Germany (Fuchs et al. 2003) reports that manually removing mature skunk cabbage Lysichiton americanus was not effective as plants build up a seed bank which lasts for at least eight years.  After the first four years of a twice yearly total removal programme, plants with leaf length in excess of 80cm were no longer found.  However, a large number of plants still needed to be removed each year.  In 2008, at least 3,773 skunk cabbage plants were removed in the Taunus region. The programme involved removal of all skunk cabbage stands twice each year.  No further information was available.

    Study and other actions tested
Please cite as:

Aldridge, D., Ockendon, N., Rocha, R., Smith, R.K. & Sutherland, W.J. (2020) Some Aspects of Control of Freshwater Invasive Species. Pages 555-87 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

Control of Freshwater Invasive Species

This Action forms part of the Action Synopsis:

Control of Freshwater Invasive Species
Control of Freshwater Invasive Species

Control of Freshwater Invasive Species - Published 2017

Control of Freshwater Invasive Species Synopsis

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, terrestrial mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 17

Go to the CE Journal

Subscribe to our newsletter

Please add your details if you are interested in receiving updates from the Conservation Evidence team about new papers, synopses and opportunities.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust