Meet the plant
American skunk cabbage (Lysichiton americanus) has huge leathery leaves between 40cm – 1.5m, and bright yellow flowers up to 45cm, which resemble those of Lords and Ladies. Its seeds disperse via waterways but also probably by birds and animals.
It is found on pond margins, stream sides and wet woodlands.
It was widely planted as an ornamental plant besides ponds and in bog gardens and was still on sale as recently as 2009, it gradually escaped from gardens and into the wild.
Download the American skunk cabbage ID guide
Read more about American skunk cabbage
The large leaves and dense stands of the plant lead to it out-competing smaller plants due to its shading effect and can cause extensive damage locally to native flora including vascular plants and mosses. It can grow in shade or full-light and in a range of different soil conditions and thrives in disturbed environments.
Given the popularity of this plant in gardens and its continued introduction into the wild, the problems are likely to increase. Although initial invasions will expand slowly, once this plant takes hold it can spread rapidly and become a serious problem.
Management of American skunk cabbage
Chemical control is the recommended option, especially for dense stands, but as it grows usually in water only suitably qualified people can undertake this. We’ll be undertaking herbicide application by spraying and stem injection during the late summer months, July-Oct.
The plant can be dug out by hand, but this must include the main rhizomes from underground, and as it is thought that it is capable of establishing new plants from rhizome fragments. Care is needed to collect all plant matter if digging it up and plant material must be destroyed through burning, drying out (away from watercourses) or secure composting. There are mixed reports on the success of removal using this method.
A large seed bank can build up in the soil and can remain viable for around 8-9 years, so control is a lengthy and ongoing process. However the plant is slow growing and only plants of three years or older produce flowers and seeds.
The risk of spread of American skunk cabbage can be reduced in the short term by cutting the flower before it sets seed. It usually flowers in spring before leaves appear.
Read more about American skunk cabbage management and control
We want to create a network or local people who have their pesticide application qualifications who can treat American skunk cabbage in their local area, these might be individuals, students, estate workers, ghillies, rangers, wildlife groups, community groups.
Find out more about volunteering and getting qualified
Where is it?
American skunk cabbage is localised within our project area, and is found in patches in the River Spey, River Tay, River Dee, River Ness and River Conon catchments and at isolated sites within Wester Ross and West Sutherland.