Himalayan Balsam – it’s an alien plant invasion

A Ranger pulling Himalayan Balsam in the Lake District

Himalayan Balsam is an invasive non-native plant so robust and vigorous that’s it’s become a real problem in the Lake District, smothering and pushing out other indigenous plants in vast swathes along riverbanks and lakeshores.

Himalayan Balsam was introduced to the UK in 1839 as a greenhouse and warm garden plant and, within a few years had escaped into the wild. Once growing, Himalayan Balsam can spread at a fearsome rate and the problem here is now so huge that in the central Lake District alone, our Rangers and volunteers spend at least 50 days between them tackling the plant every year.

What’s the problem?

It’s a cunning invader; each plant produces hundreds of seeds each year which it can project by up to 4 metres through an explosive release from the seed pod. This highly effective method of self-propagation creates dense thickets of Himalayan Balsam up to 2.5m high, leaving little or no space for other native species to compete.

It’s not all bad, it’s actually quite pretty with its pink orchid-like flowers, but aside from the obvious threat it poses to our biodiversity in the Lakes, it also poses a real threat to the stability of our riverbanks.  Himalayan Balsam is an annual plant which means that it dies back in winter, leaving riverbanks bear with no roots holding the soil together, leading to erosion and siltation of our rivers.

A Himalayan Balsam flower in the Lake District

Tackling it

June is usually the month that we ramp up our annual assault on the Himalayan Balsam around Langdale, Windermere and Ullswater. Our approach is not particularly technical; it’s simply takes lots of people getting stuck in to pull the plants out from the roots before they set seed. We are grateful for the support our Rangers receive from local volunteers and were also proud to assist the South Cumbria Rivers Trust with their annual Balsam Bashes.

What can you do?

Well actually, by being a member of the National Trust, visiting our places, cafes and carparks you are already supporting our work to tackle invasive plant species, every penny you spend with us helps us to look after the Lake District. So, thank you very much.

If you do feel compelled to do more we have many countryside conservation volunteering opportunities here in the Lakes, you can find out more here on our volunteering page.

Alternatively, you could keep an eye on the South Cumbria Rivers Trust webpage for upcoming Balsam bashing events, we will see you there!