The Big Balsam Bash at Blickling
Himalayan Balsam is an invasive plant species that is threatening our rivers and countryside. It grows along our river banks at Blickling, outcompeting native species and causing erosion.
What is Himalayan balsam?
Himalayan balsam (Impatiens glanduliflora) is a large plant native to the Himalayas. Its growth is widespread in the northern hemisphere, where it's largely considered an invasive species.
Himalayan balsam can grow to more than three metres in height in a year and each plant can produce 800 seeds. These seeds are dispersed up to seven metres away from the parent plant, most frequently by humans and animals brushing past the ripe seedpods.
If the seeds land in a stream or river they will be taken downstream, where they will start a new colony, which is one of the reasons why this plant is so difficult to control.
Why is balsam a threat to our rivers?
Whilst it may look pretty with its pink and white flowers, Himalayan balsam spreads rapidly forming dense colonies which crowd out native plant species.
In the winter it dies back exposing bare soil, which is vulnerable to erosion by weather or flood waters. This can allow harmful amounts of soil to enter our rivers, preventing sunlight from reaching river plants and reducing the amount of oxygen available for fish and river invertebrates. Himalayan balsam therefore damages the health of rivers and the plants and animals that depend on them.
The River Bure runs the entire length of Blickling’s northern boundary and is a rare and beautiful chalk stream. Every summer the Countryside team remove Himalayan balsam from the river’s banks. This work is part of our Riverlands programme, a five year project, where we're working with local communities, businesses and land owners to improve the health of the River Bure, and improve the way that people interact with their local rivers and streams.
How to identify Himalayan Balsam?
In the spring the hollow stems are pinky red with green shiny leaves. The flowers appear in June and continue until October. These are purplish pink to very pale pink (almost white) and are slipper shaped on long stalks.
A ‘Balsam Bash’, involves pulling up the Himalayan balsam, to prevent it from setting seed and spreading further along the riverbank. Clearing a site like this reduces the amount that will grow in the same place in future years. Our Countryside team pull plants throughout June and always clean and disinfect their boots before going to different river sites to prevent the seeds dispersing far and wide.
In past years, we've invited our supporters to help us on a Balsam Bash, and due to the shallow roots of the plant, pulling it out of the ground is surprisingly easy! However, this year with the pandemic, it isn't possible. We hope to be able to invite you back to get involved with this rather satisfying activity in 2022.