Botanical Exuberance: On Himalayan Balsam


Through the summer, when walking through the woods and beside roads, I find my fingers extending out to touch a green and leathery seed pod. In response, the ovary wall curls back, and with a pop sends a shower of seeds to the ground. It is a compulsive and absent-minded habit which I’ve had since childhood, a botanical equivalent of popping bubble wrap. It’s generic name is a come-on, Impatiens, it says; go on, pop me, now. I often find little groups of children standing around patches of balsam in the summer, most of them attending to nature more closely than they would otherwise. It is a purely visceral way to relate to nature, and one which even the most nature-alienated child understands. Even if they don’t know what berries are safe to eat, they know what happens when they touch those musty smelling plants. Pop, whizz. Whereas to them the rest of nature might seem like a uniform green swathe, these plants are bursts of fireworks.
Himalayan Balsam is a widely reviled alien weed, but as with many hated plants it is difficult to distinguish the actual ecological harm it does in a specific case from general displeasure at its presence. It is not a native (whatever that means) of Britain, having been introduced from India around 1839. They had the tenacity to escape from cultivation, establish themselves in the wild and be so conspicuous there; a foreign threat in English soil. It is widely claimed that balsam smothers native vegetation, blocks waterways and then leaves the bank bare to erosion in the winter, and therefore should be eradicated. However, is it is difficult to distinguish whether the presence of the balsam causes the ecological damage, or whether balsam is taking up the opportunities opened up to it by the ecological damage that we have caused.
Balsam thrives on disturbed ground with a rich soil, such as the banks of eutrophicated waterways, the habitats a diverse native floral community abhors. Furthermore, balsam has it’s greatest coverage in August and is inconspicuous before July. By the time of it’s ecological dominance in a site, most of the delicate native species have finished flowering and have paid in this year’s contribution to the seed bank. Given the conditions of habitat and timing, it is in many cases difficult to imagine what else would be able to grow there. The most robust argument put forth against balsam is that by dominating river banks in summer bank then dying back in the winter, they do not give a thick vegetative covering to the soil, which then washes away in the winter storms. Annual plants do certainly cause problems by withdrawing their soil support every winter, but it is a problem of all annual plants, both treasured native and imported villains. Balsam certainly causes a problem if it replaces perennial plants, but the real problem lies in what caused the perennials to disappear rather than the presence of a particular sort of annual plant.

These lines of evidence point to balsam’s success being due not to some innate marauding nature, but rather to its ability to thrive in habitats of our making. Every site does have a different history, but balsam tends to step in when delicate natives begin to disappear due to a sickness in the ecosystem. In cases like this, balsam may be the sticking plaster, barely managing to maintain the ecosystem in the face of collapse. To then come back in and try to remove a thriving community of balsam would be to invite the true villains, such as Japanese knotweed, to twist the system into their own reign of tyranny. Or even worse, maybe nothing would come after the balsam, and the soil would slip off into the river. We cannot recreate Eden once we have fallen, Biblically and ecologically speaking, therefore we should work with the world as it is now, and try to preserve its ecological exuberance.
Balsam is an exuberant plant, attracting inquisitive human hands and bees alike. Richard Mabey in his book Weeds makes reference to balsam’s vernacular name “bee bums”, and it is very apt. In a particularly musky patch opposite a casino on waste land in the centre of an English town I have seen almost every flower occupied by a bee at one time. They emerge from the jarringly orchid-like flowers whitened with the sheer weight of pollen they have picked up, as if they had lain out in snow fall. It is a sight of bold fecundity; nature decadent in it’s reproduction. It is hard to condemn something that so visibly thrums with life. It has been argued that the rich nectaries of balsam are a vulgar sideshow distracting the pollinators from native plants. But as the plant blooms after most of the precious wildflowers have already been pollinated, balsam may not reduce the fecundity of native populations significantly in much of it’s range. The bees clearly adore it’s nectar, and it is difficult to deny them this. It may be a much needed source of nectar when stocks begin to flag in the lead up to winter. And given current anxieties about the extinction of honey bees, it can only be hypocritical to condemn a plant for giving pollinators too much of a good thing.
I could never say I liked balsam. It is too much, too big and quick and smelly. It’s scent is like dried sweat on a t-shirt left out to dry into the sun, there is nothing floral in it. It is both imposingly large and paper-thin. It’s thin walled bamboo-like stem gives it a sense of effemerality, which is corroborated when the stems break and crash to the floor in the autumn, turning a once jungle-like thicket into a landscape like a village razed to the ground. But I have a respect of an opportunist, as in dire situations the alternative to an opportunist is not it’s fragile replacement but rather an vacuum, alien and detestable.