Himalayan Balsam (Impatiens glandulifera) is an appealing plant for foragers. Not only are most parts edible but its attractive pink orchid-like flowers make it an easy spot, while its violently exploding seed pods create a curious addition to the UK’s river corridors.
Himalayan Balsam is a relative of the Busy Lizzie and was first introduced to the UK as a cheap garden plant in 1839 (CABI.org). At one time, it was even marketed as “Mr Noisy’s Exploding Plant”, a novelty plant for children (The Independent, 2013). However, it is a successful invasive and has gone on to colonise 23 European countries, as well as being found in the US and New Zealand.
In the UK, it is now naturalised and is a rapid coloniser of river banks. It crowds out native species and causes erosion, as every year its root stock rots once the adult plant is killed by the first Autumn frosts.
It is not hard to identify once fully grown. Its red-tinged stems can grow to over 2m and are found along the bank of water courses, ditches and steams. Those stems bear a passing resemblance to that other much-maligned invasive Japanese Knotweed. Both plants are on the Schedule 9 list of The Wildlife and Countryside Act (WCA) 1981, Section 14(2), which makes it an offence to plant or cause them to grow in the wild.
The hooded pink or white flowers, which appear in the summer months, make this plant difficult to confuse with anything else. They are shaped like an old Policeman's helmet or, when turned upside down, a Persian slipper. Which is where some of its other common names originate.