HIMALAYAN BALSAM REMOVAL
Our rivers serve as vital wildlife corridors for a diverse array of animals, birds, and plants. They offer free movement between habitats, safe refuge, abundant food supplies, and support the completion of many species' lifecycles. However, invasive non-native species (INNS) frequently become part of our river ecosystems. These plants and animals can outcompete native species, spread disease, cause habitat loss, damage riverbanks, and prey on native wildlife.
Himalayan balsam (Impatiens glandulifera) has quickly become one of the UK's most invasive weed species, spreading across riverbanks, waste ground, and damp woodlands. It outcompetes native plants for space, light, nutrients, and pollinators, often displacing other species and reducing native biodiversity.
The Essex and Suffolk Rivers Trust conducts seasonal Himalayan balsam clearance in two catchment areas. The first area includes the River Stour and its tributaries, the Rivers Box and Brett, along with the Brett's tributaries, Lavenham Brook and Bildeston Brook. The second area focuses on the River Fynn, located north of Ipswich.
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What is Himalayan Balsam?
As its name suggests, Himalayan balsam originates from the Himalayas north of Pakistan and India and was originally introduced to the UK in 1839 as an ornamental garden plant. However, it quickly spread beyond gardens and became an invasive weed along riverbanks and ditches, especially close to towns.
Himalayan balsam is fast-growing and spreads quickly, invading wet habitat at the expense of other, native flowers. A distinctive plant with reddish jointed stems and long, green, oval-shaped leaves, the flowers range from fuchsia to pale pink in colour and tend to appear between June and October. Its explosive seed pods aid its spread by sending the seeds into the river, causing further dispersal downstream.
Download the full ID Sheet or visit www.nonnativespecies.org for more information.
If you find Himalayan balsam, you can report your siting through the INNS mapper project.
Stour Catchment Project
We have partnered with Essex and Suffolk Water on Himalayan Balsam removal projects focusing on the Rivers of the Stour catchment, the Stour, Box, Brett and its tributaries. This projects have run from 2021-2026 and the ESRT are hopeful that a new round of work can be funded and scheduled for 2027 and beyond.
This project is funded by the Essex and Suffolk Water Branch Out Invasive Non-Native Species (INNS) fund. In 2025 we secured additional funding from the Dedham Vale National Landscape & Stour Valley Sustainable Development Fund and in 2026 additional funding has been provided through the Affinity Water INNS Out scheme.
In 2025 our team and volunteers cleared 1.1km of the River Box, 1.4km of the River Stour, 2.9km of the River Brett and over 500m of other tributaries in the catchment. In the future this can be extended with additional partnership working and volunteer hours.
River Fynn Project
We began our work on the river Fynn in 2024. In both 2024 and 2025, 6km of Himalayan balsam was cleared from Tuddenham St. Martin to beyond Little Bealings, just upstream of the confluence with the River Lark. Work in 2025 has shown our efforts have greatly reduced balsam in this area. A small amount of work will be completed here in 2026, with funding provided by Essex and Suffolk Water's Branch Out Scheme. The ESRT are currently evaluating the best strategy for this river for 2027 and beyond.
This project was funded by the Anglian Water Invasive Species Fund, the grant being administered by the Cambridgeshire Community Foundation during the period 2024-2025.
River Pant Project
Following investigations, both during the 2024 surveying for the Pant and Blackwater plan and some work during the 2025 balsam season, the river Pant has been selected as the next river for targeted action by the ESRT. Around 300m was cleared in 2025 with aims to clear several kilometers in 2026. We are seeking willing volunteers in this area to assist with clearance.
Funding for this work has been provided through Essex and Suffolk Water's Branch Out programme as well as well as the Environment Agency's LWEG programme.
Further Work
In 2026 we hope to expand into new river catchments, offer additional volunteering opportunities and experiment with new techniques. If you are a riparian landowner in Essex or Suffolk and have Himalayan balsam on your watercourse then contact our team for help and advice. We are also always in need of further funding to continue our work improving our rivers. If you feel you can contribute, check our donations page for more information.