Himalayan Balsam is common beside UK rivers
Himalayan balsam was introduced as an ornamental plant in the 19th century but has since grown rapidly and infested the UK, mostly over riverbanks. It is classed as a non-native invasive species as it was introduced from the Himalayas region to the UK and has since dominated many ecosystems, threatening native species as it out competes them for light and nutrients. The plants are also capable of producing an incredible amount of pollen, therefore attracting much of the local wildlife to the detriment of many other plant species that rely on wasps and bees for pollination.
Himalayan balsam has almost been completely removed from the River Alyn because of the efforts of the North East Wales Wildlife Trust, who have been uprooting the plants on the riverbanks since 2009. Himalayan balsam is a shallow rooting plant, unlike Japanese knotweed, and can easily be taken from the ground without much effort or damage to the ecosystem. When the infestation dies away in the winter and leaves the riverbank barren, there is then a greater threat of soil erosion. There are, however, ways to control Himalayan balsam whilst reducing the threat of soil erosion.
The North East Wales Wildlife Trust believed the Himalayan balsam on the banks of the River Alyn was becoming a problem and over a number of years they removed prior to seeding all juvenile plants from the riverbank to reduce the risk of further infestation. The River Alyn is a feeder to the River Dee, which is a protected site so it was important to limit the spread of the infestation. The North East Wales Wildlife Trust felt that with enough volunteers they could efficiently clear the riverbank and eradicate the weeds from the area before they infested the protected area. After many years of hard work on the riverbanks, the Himalayan balsam has been 98% eradicated.
For further advice on Himalayan balsam control strategies and help with any other invasive weeds (Japanese knotweed, Giant hogweed etc.) call Invasive Weeds Agency on 08457 676 9252 or contact us here.
IWA. Getting to the root of the problem.