So, What is Himalayan Balsam?

The Himalayan Balsam (scientific name: Impatiens Glandulifera – or for Welsh readers: Jac y Neidiwr) is the most widespread non-native annual flowering plant in Britain.

It’s native to the Himalayas, hence its name, and despite it being a gorgeous flowering annual in its native habitat where it would normally be found growing on mountains, in Britain, it’s a weed! 

“a plant that is not valued where it is growing and is usually of vigorous growth

especially : one that tends to overgrow or choke out more desirable plants”

Source: Merriam-Webster 

 

How to Identify Himalayan Balsam

These are most prevalent in the spring and summer. They die back in winter.

The early stages of growth will be seen from March in any area where the ground is damp.

They won’t flower until after spring, so from March to June, these can be identified by the seedlings, the stem and the shape of the leaf. 

The seedlings are green with a reddish midrib, sometimes with the stem having a red tinge, too. That is also carried through on the slightly serrated leaf edges.

The leaves grow in whorls of 3 to 5 leaves (forming a star shape), shooting out from the stem and the reddish colouring can be around the leaf edges too.

July to September is when these bloom. That’s when they’re far more easy to identify!

You’ll see the same leaf structure and reddish tinge to the midrib and stems, but it’s the flowers that give the Himalayan Balsam its signature feature.

When in bloom, it has pink flowers in the shape of a trumpet, which is where it gets its nickname of the ’Policeman’s Helmet’. 

Himalayan Balsam in Pictures

 

The Seedling Stage 

Photo Credit: Rosser1954 | CC BY-SA 4.0, via Wikimedia Commons

Even from the cotyledon leaves, there’s a slightly red colouring where the first leaves emerge from the stem. 

Himalayan Balsam in Bloom

Photo Credit: Mick Garratt | CC BY-SA 2.0 | Himalayan Balsam by the River Leven

 

Notice the clusters of vibrant flowers and the star-shaped whorls of leaves protruding from the red stems. In full bloom, the flowers are 3 to 4 cm. 

Seed Pods after Flowering

Photo Credit: Phillip Halling | CC BY-SA 2.0 | Himalayan Balsam seed pods

 

As the season comes to an end, the flowers die back and the plant goes to seed. These pods hang from where the flowers were and inside each pod are  4 to 16  seeds. Once ripe, the seed pods burst open, distributing the seeds some distance. 

Is the Himalayan Balsam an Invasive Species

Not only is it an invasive species, it is among the MOST invasive species in the country.

A dangerous one at that, because it impedes biodiversity and once it dies back, it leaves bare soil at risk of erosion.

According to CABI (Centre for Agriculture and Bioscience International), the Himalayan Balsam has an annual spread rate of 645 km2. That’s nearly a 250-square-mile radius per plant. 

When each flower on the plant dies off at the end of its life cycle, it goes to seed. Each seed pod produces between 4 and 16 seeds. At the slightest touch, those pods explode open, catapulting the seeds a phenomenal distance.

It could be people pinching the seed pods, birds pecking at them or bees landing on them that cause the seed pod to open. When they do, each pod springs open with such velocity that it propels the seeds up to 7m in whichever direction the wind blows. 

Whilst each seed can reach a distance of 22ft (7m), when they’re near water, they can spread further because the seeds are buoyant, They’ll float in water and germinate at whichever part of the riverbank they reach further downstream, which is why these are often found along riverbanks and canals. 

Other Ways the Seeds of the Himalayan Balsam Gets Spread

Most waterways in Britain are beautiful nature walks.

Dog walkers frequent the areas, and that’s ample opportunity for the tiny seeds to be carried in a dog’s paw, or the treads of people’s shoes.

Wildlife can also disperse seeds including rabbits, hares, deer, sheep, cattle, and birds and bees that frequent the wildflowers near riverbanks.

For those living in rural areas where these are most often found, if you ever find these sprouting in your garden, you will need to get rid of Himalayan Balsam because it’s illegal to grow it in Britain or allow it to grow unchecked. 

Where Himalayan Balsam Commonly Grows in the UK

Wetlands, or any wild area with moist soil. In the UK, that’s mostly beside waterways like rivers, canals, and wetlands such as marshes, swamps and bogs. 

Is Himalayan Balsam Beneficial to Wildlife?

For the most part, no, and that’s because they reach massive heights. Himalayan Balsam can grow up to 10 feet tall. At that height, they’ll dwarf every other wildflower growing near it, starving them of sunlight and essential nutrients.

This, in turn, reduces biodiversity for wildlife. 

Along riverbanks where there are wild flora like hemlock water dropwort, Bulrush (reedmace), marsh bedstraw, and Purple loosestrife, they get choked out by the vigorous growth of Himalayan Balsam.

During the summer months when the plant is in bloom, it’s a godsend to honeybees, because each flower on the Himalayan Balsam can produce 19 microliters of nectar in 24 hours with 48% to 53% sugar content. 

The real issue is biodiversity, because while there’s an abundance of nectar and pollen for wildlife in the summer, in the winter when Himalayan Balsam dies back, it leaves the ground soil bare, putting it at risk of erosion.

Furthermore, where hemlock and other larger wildflowers could be used for wildlife to take shelter over winter, those won’t be of the size they usually are because they’ll have been choked out from the sheer size of the Himalayan Balsam. 

Himalayan Balsam gives wildlife an abundance of food in the summer at the cost of shelter in the winter. 

 

The Economic Impact of Himalayan Balsam

Himalayan Balsam costs the economy millions every year because of soil erosion contributing to river scour.

Road and rail bridges require higher maintenance, and flood prevention measures need to be put in place to mitigate the risk of flooding caused by riverbank subsidence.

A 2003 report by the Environment Agency on the cost of eradicating Himalayan Balsam from the UK was estimated to be between £150 to £300 million. Fast forward to 2022, and the British Geological Survey estimates the costs to the economy from river erosion is around £336 million annually! 

So, after wondering what exactly Himalayan Balsam is; In a nutshell, Himalayan Balsam is among the most dangerous weeds in Britain!