Himalayan Balsam

Introducing Himalayan Balsam

Invasive Non-Native Species on the Wye

Himalayan Balsam (Impatiens glanulifera) AKA: Policeman’s Helmet, Indian Balsam, Jac y Neidiwr (Welsh). Colloquially known as Bee-bums, Poor Man’s orchid, Jumping Jacks and Stinky Pops.

Himalayan balsam ID Sheet

Himalayan balsam Good Practice Management Guide (RAPID)

Himalayan balsam is an attractive looking plant, with a stout, hollow stem, trumpet shaped pink/white flowers and elliptical shaped green leaves.

Introduced to Kew Gardens from Kashmir in 1839, it spread via its seeds – both individuals passing the seed on to other gardeners or beekeepers and seeds floating down rivers, lodging in muddy banks and germinating. It is now widespread across the UK’s lowlands and is ranked high on the list of Europe’s worst invasive plants.

A relative of the Busy Lizzie, this is our tallest annual at 2-3 metres (6-10ft) in height, with masses of sweet smelling pink/purple flowers (July – Oct). Its explosive seedpods fire hundreds of viable seeds up to 7 metres away, enabling it to colonise new areas of countryside incredibly quickly. Its seeds are easily transported via water, but also by animals and humans.

It has the highest growth rate of any plant in the herb layer, tolerating a wide range of conditions and growing to dominate an area in just one season. It particularly thrives in moist, semi-shaded damp places such as banksides by slow-moving watercourses.

Himalayan balsam is listed under Schedule 9 to the Wildlife and Countryside Act 1981 with respect to England and Wales. As such, it is an offence to plant or allow this species to grow in the wild.

The Issues

Himalayan balsam is our most dominant invasive in the Wye Valley AONB. It has taken over long stretches of the River Wye and tributary banks – our most ecologically sensitive areas. It is also establishing itself in gardens, fields and woodlands, growing along culverts, footpaths and roads. The list of negative impacts is lengthy and serious:

  • Against the shading effects of Himalayan balsam, our native wildflowers such as purple loosestrife, great willow herb, meadowsweet and marsh woundwort stand little chance of survival. 
  • When the balsam dies back every winter it leaves bare earth that is vulnerable to erosion, especially as our climate becomes wetter and stormier. Without stabilising vegetation we’re losing more stream bank and river bank, including the wildlife that lives within it, such as water voles and kingfishers.
  • The increasing soil and silt in the rivers and streams is reducing water quality and smothering aquatic life, including fish spawning grounds and vital water crowfoot beds.
  • The balsam produces a bonanza of nectar through the summer and into autumn, but has been shown to monopolise insect pollinators to the detriment of native flowering plants.
  • There are also studies showing that balsam may deplete mycorrhizal soil fungi, preventing the regrowth of native plants. 
  • And of course the balsam impacts on our own enjoyment of these special places. Growing so tall and densely along riverbanks it can impede visibility and access and alter the appearance of our landscapes and riverscapes.
  • Back in 2003 the Environment Agency estimated that total eradication from the UK could cost as much as £300 million. That cost is obviously far higher now as it has colonised much more of our countryside in subsequent years. To give you an idea of the rate of spread, in the 50 years after being introduced (1839 -1890) it was estimated to have spread at a rate of 645 square kilometres every year.

We regularly hear ‘it’s not that problematic is it?’, illustrating that many people still don’t know about the damage Himalayan balsam can cause. It is gradually filtering through the public consciousness, and social media is helping, but we seriously need to up our game here. We all need to get talking about it and encouraging everyone to ‘do their bit.’ 

Managing Himalayan Balsam

AONB Volunteers

Check, Clean, Dry Logo

What we’re doing

The key with balsam is to reduce the risk of re-infestation and because the seeds are readily carried by water, this requires a river catchment approach, working from the headwaters to the sea. Since the AONB team is unable to coordinate at the full Wye catchment scale (the AONB boundary lies south of Hereford), we’re focusing on our local, sub-catchments, controlling it from the headwaters down towards the main river. We know this is achievable. 

Piloting this approach for us is the brilliant volunteer group, The Narth & District Footpath Group. In 2018 they mapped the balsam across the Manor Brook catchment (Whitebrook) and they’ve strategically removed the balsam, working from the headwaters down stream. Their work through 2019 is estimated to have removed up to 90% of the balsam at 9 sites. In 2020 the group removed the remaining 10% and they’ve tackled a new area, removing over 5,500 plants! It certainly proves ‘where there is a will, there is a way’. We will continue to support The Narth & District Footpath Group, and we are looking to extend this proven, community-led approach to further sub-catchments.

At Brockweir this August we invited willing volunteers to join us in Operation WISPER to help pull balsam up along the main river and adjacent woodlands between Brockweir and Bigsweir and map the extent of balsam and other species in the upper reaches of the local sub-catchments. This was a resounding success, clearing a wide area of balsam, helping to raise awareness of this problem species and locate new sites to add to our action plan. Keep an eye on Dates for your Diary for 2022 events.

We’re currently working with The Narth Volunteers and partners to develop a Community Toolkit to help answer all those questions posted across social media every summer – what can we do, where can we do it, what is the best method? This kit will help those individuals and community groups who want to take action take action. We will be launching this well in advance of next year’s balsam pulling season – so watch this space! 

What you can do
It’s all in the timing!

The good news is that Himalayan balsam is very easy to pull up. Its stout, reddish-translucent hollow stems rarely have roots more than a few centimetres deep and can be lifted out with a satisfying tug. Take care to pull the roots out i.e. if the stem snaps try again! Once pulled, leave the plants spread out on the ground, ideally with roots not touching soil, so they can dry out and rot down. Stamping on the stems also helps to ensure they wont re-root.

It’s critical pulling is done before the seed pods are ripe, and ideally before they start to flower – so May, June, July is the optimal time. Bear in mind, some follow up work might be needed as the change in light levels is likely to stimulate seedlings to sprout up.

Try not to get dismayed! Remember, every single plant pulled up means there’s between 500-2,500 less seeds germinating next year. 

Where can I pull it?

If you see Himalayan balsam in your garden or along Public Rights of Way – May, June and July (even into early August depending on the growing rate) – get pulling up those plants! If you see it growing in a neighbour’s garden, gently point it out to them and offer to help them remove it. If you know a local landowner who’s struggling with controlling it, mobilise your friends and neighbours to help them tackle it. Undoubtedly, community spirit will be the key to getting this species under control. 

If you fancy bringing together your neighbours to balsam-pull along your local paths or at a local site, or forming a group to tackle balsam at community-scale then do get in touch with us. 

Don’t be a carrier!

Later in the season – August onwards – do think about those exploding seed pods. If you’re walking, running or biking through balsam-infested areas please brush off your shoes and tyres before entering an area that is balsam-free. The seeds readily stick to boot soles, bike tyres etc. and wouldn’t it be awful if we as individuals were helping to perpetuate the problem!

Remember the mantra: Check, Clean, Dry

 

Photos courtesy of NNSS Home – GB non-native species secretariat (nonnativespecies.org)

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