We’ve all heard the horror stories of gardens invaded by Japanese knotweed, ground elder and bindweed.

And over the last year giant hogweed as hit the headlines as a nasty invasive plant that is spreading through the country "burning’ children and dogs in its wake. But with all the focus on the usual suspects and this big meanie, many people are unawares of a growing threat

to our wildflowers and gardens, quietly spreading across the country.

Himalayan balsalm, Impatiens glandulifera, is a close relative of the much loved busy lizzie. This non-native invader produces pretty pink flowers from June to October, and is the tallest annual plant in the country, easily reaching a height of 2-3 metres in one season. It is commonly found along waterways, canals and rivers, but I’ve started to see it increasingly appearing in gardens.

The reason for its success is its explosive means of distributing its seed. According to the RHS, each plant is capable of producing up to 800 seeds in seed pods that when ripe, burst open with the ferocity of a mouse triggering a mousetrap, shooting the seeds up to a distance of 7 metres from the parent plant. The seeds are then carried by water, humans (on clothing and shoes) or animals (on their fur) to new locations, including your own garden.

The (sort of) good news is that it's an annual. This means if you can get it out before it sets seed, you have a good chance of eliminating it. Despite its size, it's surprisingly easy to pull out of the ground by hand with a root system far smaller than you’d expect for such a towering plant. In large areas if you don't have the time to dig out all the plants before they set seed, cut off the tops of the plants when they are flowering to stop them setting seed. You can then deal with the stumps at your convenience.

The main problem in the countryside is with plants eroding river banks, clogging up rivers and streams leading to flooding and crowding out native species.

As a result councils across the country have been encouraging the "off with their heads" approach when you come across the plant in the wild to keep populations down. Originally confined to wet areas, it seems the plant is adapting to cope with drier soils such as gardens and roadside verges. Not good.

Beautiful flowers, quick to establish and affordable to all, Himalayan balsam was introduced to the UK as an ornamental in the 1800s. We’ve also got that century to thank for the aforementioned nasties too – bindweed, giant hogweed, ground elder and Japanese knotweed.

They’ve got a lot to answer for those Victorians.