Scientific name: Impatiens glandulifera
As its name suggests, Himalayan balsam is from the Himalayas and was introduced here in 1839. It now an invasive weed of riverbanks and ditches, where it prevents native species from growing.
StatsHeight: up to 2m
Invasive, non-native species.
When to seeJuly to October
AboutHimalayan balsam was introduced as a garden plant in 1839, but soon escaped and became widely naturalised along riverbanks and ditches, especially close to towns. It is fast-growing and spreads quickly, invading wet habitat at the expense of other, native flowers. Its explosive seed pods aid its spread by sending the seeds into the river, causing further dispersal downstream.
Our largest annual plant, it flowers from July to October.