Himalayan balsam at Watermead

A couple of years ago I walking along the river Ribble in Lancashire and I was struck by the ubiquitous presence of an unfamiliar stinky pink flower. It was everywhere and in many places the only species present. It was Himalayan Balsam (Impatiens glandulifera), an invasive garden plant that escaped from Kew Gardens back in 1839. In growing by the river they have an efficient mechanism for seed dispersal and seem to appear at new spots along a river in an ever marching tide of pink stink. Earlier this year I spotted a single plant down at Watermead. I would now estimate that a significant fraction of the biomass down at Watermead is Himalayan Balsam. It lines the river from Watermead bridge all the way to King Lears lake. What a nightmare. There is only one effective way to kill off this plant, and that is pulling it up before it flowers. Most control measures are slightly reactionary in that people normally only notice it when it flowers and then start to pull it up. But pulling it up when it is flowering will trigger the release of its explosive seed pods and scatter thousands of seeds back into the river. What a crafty plant.