Posted 28th Jun 2018 by Peter Byrne
Volunteers are being called on to help to tackle Himalayan Balsam, a non-native invasive species
The Wildlife Trust of South and West Wales have been tackling Himalayan Balsam Impatiens glandulifera, a non-native invasive species. It was introduced to Kew Gardens in London in 1839 as an exotic flower, and then spread as a colourful garden species, doing particularly well in wet areas.
Despite being an annual, the pretty, yet ecologically damaging flower can grow up to 10 feet tall in one spring and summer season. It also has the ability to fling up to 800 seeds as far as 13 feet from each plant. This is in comparison to native plants, which will either grow quickly to a short height or tall slowly. With the seeds floating very well, they spread rapidly down the water courses, meaning that if it isn't controlled or eradicated, it can quickly spread to out compete our native wildflowers, as it puts them in the shade and steals nutrients too.
The attractive flowers are also likely to distract pollinating insects from fertilizing our declining native wild flowers - since it is a non-native plant from a distant part of the globe, there are no natural predators, there are no natural predators. As a result, balsam is mainly untouched by herbivorous mammals, birds, reptiles and invertebrates. This allows balsam uninhibited growth and colonisation too.
The Wildlife Trust is aiming to get the upper hand against invasive species on their reserves, including other Himalayan balsam.
In Gelli Hir, a reserve on Gower near Three Crosses, there has been a consistent effort over several years from a team of volunteers who are looking to beat the plant. It can be hard to access much of the affected areas there, with plants found between trees, in bramble thickets and in wet/boggy ground. However, there's no need to fear, as it's easy to pull out. The most effective way to get rid of it is to pull it up by the roots and leave it to rot in heaps or strategically placed builder’s sacks so it's easy to access and cannot spread further.
Once it has been pulled, the bottom node (fat joint part) should be squished, with plants hung up in trees so the roots dry out, cannot touch the ground, or any moisture giving the branch time to regrow.
Volunteers were able to make significant progress last summer, clearing the entire area from the stream's entrance to the reserve all the way down to the pond, in the process making a trip to the island to pull out every plant they could find.
In the last year, there were three tonnes that were collected, bagged, and left to rot down. If you would like to collect more, you can find out more here: www.welshwildlife.org/things-to-do/volunteering/