Each plant can produce up to 800 seeds. These are dispersed widely as the ripe seedpods shoot their seeds up to 7m (22ft) away. It therefore spreads quickly and forms dense thickets, altering the ecological balance and character of woodland and wetland habitats. It produces a lot of pollen over a prolonged season and is attractive to pollinating insects. There is concern that its presence may therefore result in decreased pollination for other native plants.

Removing Himalayan balsam.

There have been a numbers of areas in Haw Park affected by Himalayan balsam and the Friends group have undertaken the eradication of this invasive weed in a series of ‘Balsam Bashes’. These ‘bashes’ involve getting through the dense growth of nettles and brambles, to attack the balsam by pulling the plants out of the ground. Fortunately the balsam is shallow rooted and can be pulled-up easily. The plants are then placed in black bin bags and disposed of by the rangers.