Tackling invasive plants

Dartmoor is home to precious wildlife and habitats but invasive non-native plant species are a threat because they displace native plants and disrupt ecosystems.

Invasive non-native species can be extremely costly and difficult to manage if allowed to establish.

We’re working with the help of others to stop this from happening by finding out where the invasive plants are, and taking action to prevent their spread.

The scale of the problems means we have to prioritise where we work and which threats to tackle, but every one of us has a duty to not cause these invaders to spread from our own gardens or land, and with coordinated action we know we can make a difference where they have taken hold.

The invasive plants are harmful because they out-compete our native flora for light, space, oxygen and nutrients, something which impacts on animals and insects including dragonflies, birds and otters.

Research and monitoring has shown the biggest threats to Dartmoor’s habitats are the Himalayan Balsam and American Skunk Cabbage which is why we are focusing our efforts on these particular species.

What are we doing?

Volunteers clear Himalayan balsam plants

In 2019, 57 days of volunteer effort cleared these plants from an area of 8.6 hectares (mostly woodland) and an 8.4km length of river, stream, leat and ditch. This focused on watercourses around Princetown, South Brent and Lustleigh.

We can make a real difference for the whole of Devon by making a start on Dartmoor in the headwaters or the source of the original introduction, and working downstream. The aim is to make streams, rivers and wetlands better places for wildlife and people.

Get involved

You can help us safeguard the environment for the future by getting involved in our 2020 ‘balsam bashing' volunteer days.

We’d love to hear from people who can spare a few hours and who don’t mind rolling up their sleeves and helping!

We are following all government guidance to ensure we, and you, are Covid-19 secure.

Email invasives@dartmoor.gov.uk An image of Himalayan balsam

About the plants

Himalayan balsam: With its pink flowers and ‘exploding’ seed pods, this plant is a familiar sight on streams and rivers. The best way of managing it is to pull the plant up before the seed pod pops and spreads down the river, where it takes hold and dominates native plants.

This Natural Devon factsheet has lots more information.

American skunk cabbage: This giant yellow arum lily spreads rapidly. In 2015 we found that in one river valley it had spread 1.5km from the garden where it was first introduced, and was starting to invade important wetland habitats. There's more information in this factsheet.American skunk cabbage

Tackling non-native species

While it is recognised we may not entirely eradicate them, especially on rivers as large as the Dart or Tavy, we can still make a huge difference in the upper tributaries and help deal with the problem before it gets worse.

Here's more information how you can help dispose of these plants correctly if you're a gardener or retailer.


This important work is funded from our first Moor Otters arts trail and South West Water provided additional partnership funding.

It is supported by farmers, landowners, the Duchy of Cornwall, North Bovey Conservation Group, Moor than meets the eye landscape partnership and willing volunteers.

Learn more


Devon Invasive Species Initiative

GB non-native species Secretariat