Botanical Xenophobia?

There’s a long-standing belief that dense riverbank stands of Himalayan balsam Impatiens glandulifera – like these plants flowering beside the river Tyne at Corbridge - represent a major threat to our native riverbank plants. The press loves a good ‘alien invader’ story that predicts the extermination of our native wildlife by some botanical ‘foreigner’, and it’s true that some introduced plant species that have escaped into the wild, like Japanese knotweed and Australian swamp stonecrop for example, have damaged natural habitats, but in the case of Himalayan balsam the threat is more imagined than real. Although it’s a tall, fast-growing and very conspicuous plant it’s an annual, and doesn’t compete very effectively with established riverbank perennial native plants that have dense root systems. Two recent research projects have demonstrated that it isn’t a dire threat to our flora and one very recent one has shown that it’s a positive asset as far as bees are concerned. It’s a rich source of nectar and pollen and bees visit it constantly. Sadly, once these 'alien invader' stories take root they tend persist, no matter how good the scientific evidence is that shows they are a myth. So I dare say well-meaning but misguided ‘conservationists’ will organise many more ‘balsam bashing’ events to tackle this imagined threat. Still, the plant is well established almost everywhere now, and its exploding seed pods disperse its seeds very effectively, so it will probably continue to provide a valuable food source for our hard-pressed bees for a long time to come.