What is Himalayan Balsam?

History of an invasive

Himalayan balsam is an annual invasive species native to, as the name suggests, the Himalayan plateau. Introduced as an ornamental plant in 1839, the species propensity for excessive seeding allowed it to rapidly spread into the wild where it has been a problem ever since. Along with Japanese knotweed and giant hogweed, it is one of the most invasive species in the UK.

Balsam’s capacity to rapidly breed and create massive swathes of large (can be over 4m tall!) dense species means that all other plants lose the ability to grow. Even species like gorse or broom can be overwhelmed by balsam’s propensity to grow in a matter of months to such a height. This kills off all other plant life, and as a result all of the animal and plants that rely on those ecosystems are lost and starve.

Dying off in the winter, areas where this invasive plant was growing has no root network or plant life to hold banks together. This leads to increased erosion, increased sediment in the river and risks to the riverbank.