A Mountain To Climb
Frequently, a vibrant splash of pink-purple will greet your eyes on a summer walk; Himalayan balsam is a delightful plant, with its lustrous flowers and exploding seed pods. Yet, under the façade of simple aesthetic appeal, these pretty flowers hold dark secrets.
Victorian’s endless desire to show off their riches saw an influx of exotic and exciting plants into British gardens. Of course, the more luxurious your garden, the more fashionable. Thoughtless of anything but their pride, they planted swathes of Himalayan balsam, the seeds of which then infected our countryside. The epidemic had begun.
Himalayan balsam grows very tall, (up to several metres), towering over other plants, therefore covering them in shade. Consequently, many of our native flowers cannot compete for light and space against these looming giants.
Bees are often more attracted to the flowers of this invasive plant due to their high-sugar nectar, meaning that our native blossoms have taken a double blow from these mighty foreigners. Not only are they being cramped and shaded, but bees are favouring and pollinating Himalayan balsam flowers. Plants form the basis of the food chain, so the vast array of species that rely on Britain’s natural plants are suffering from the sudden loss of their food source, such as plant-specific butterfly caterpillars.
Impatiens glandulifera, the Latin name of this invasive plant, is often seen growing on banks, as the seeds are easily transported through water. As Himalayan balsam is an annual, it will die in the winter, leaving the river bank as a pile of bare mud, with no roots to hold it together. Erosion of the riverbank is likely to occur and the increased sediment from the bankside can suffocate fish spawning beds. The loss of native flowers and plants on the bankside in winter negatively impacts upon the wildlife that lives there, such as water voles, which wildlife charities are desperately attempting to reintroduce.
A potential solution is to release a plant specific rust fungus, a natural enemy of Himalayan balsam. Over time, this would reduce the species to a controllable level. However, biological controls such as this one often take around ten years to see a marked improvement. Another solution is to simply pick the plant before the seeds develop.
It makes us redefine what a ‘weed’ really is. Rich Victorians, when they planted this in their gardens, were only thinking about having an exotic garden to show off, and perhaps they wanted it for its picturesque loveliness.
However, we are no longer in the scientific dark-ages. Any gardener or walker has access to a whole world of botanical knowledge at the mere press of a button. It is time we grew away from the need for our gardens to be full of eye-catching, yet harmful invaders such as Himalayan balsam, and started thinking about the impacts that our emotional whims can have on an entire ecosystem.
Words by Jo Cutler
Jo loves the natural world as she finds it magical and fascinating. She is a passionate beach cleaner and wants to teach people about the amazing creatures we share the planet with, in order to protect them.
First published September 1st 2018.