In the pursuit of pretty, there are two kinds of gardener who wilfully apportion several weekend evening hours to hosing down their lawn, in a heavy storm, on the darker side of dusk. There are those with a severe subterranean pest problem and those who are plain and simple bat-shit crazy, though the two are not mutually exclusive.

There are many more kinds of nematode worm, though none are true, wriggling, segmented worms at all. Close to half a million taxonomically contentious species, from the very short to the very long, inhabit almost every conceivable ecosystem on this planet, including, on occasion, the human body.

Measuring a mere millimetre in length and quietly making its benign living feeding on the microbes it finds in soil detritus the world over, the innocuous, if incredibly numerous, Caenorhabditis elegans species of tube worm is an almost entirely unremarkable example of type, excepting its unwittingly intrepid, death-defying sortie into astronomical and astrobiological history.

In February 2003, nearing the end of its 28th mission, NASA’s space shuttle, Columbia, disintegrated upon re-entry to the Earth’s atmosphere, tragically killing all seven human astronauts. Amongst the debris later recovered was a live laboratory population of C. elegans nematodes, suddenly catapulted to scientific importance on a Darwinian scale by virtue of being the first members of Kingdom Animalia to survive an unprotected and uncontrolled critical re-entry and dense atmospheric descent back to Earth from space. Eight years later, an Endeavour mission flew those pioneer worms’ direct descendants up to the extreme ecological niche of the international space station to resume the trail blazing work of their ancestors.

Four hundred million microscopic individuals, belonging to just two species: Steinernema kraussei and Heterohabditis bacteriophora, took up temporary ‘in-stasis’ residence in our kitchen fridge, between the beetroot burgers and the apple juice, until external conditions were optimum for their staggered transmission into the shallow subsurface of the garden soil. Their terrestrial mission? Not to glide an experimental cutting edge in order to further the advancement of human knowledge but to wage flat out biological warfare. To reset the scales of depredation. To halt the rapacious hostile strikes upon all that would and should be green, lush and beautiful.

Otiorhynchus sulcatus and Phyllopertha horticola: Cease and Desist! Or, more bluntly, vine weevils and garden chafers: Piss off! And take the crane flies and their freshly laid eggs of leatherjacket larvae with you!

The ubiquitous chafers were unearthed the first time I ever stamped blade to turf in this garden. The incipient weevils, however, clandestinely holed themselves up in the safety of the space I was least likely ever to dig through: the delicate root ball of Cornus controversa variegata, the wedding cake tree, whose steady demise I had been lamenting and frustratingly failing to reverse all Spring. I had misdiagnosed underground salt toxicity and/or a related pH problem. Scorching can be remedied but no amount of root washing was going to repair the devastation caused by this sprawling, crawling, voracious infantry.

The recent, almost daily, wet weather has proffered the perfect conduit through thatch and mulch for those worms whose primary means of movement is most akin to swimming. The nematodes operate as species-specific vectors, boring holes into their target grubs’ soft bodies through which they deliver bacterial pathogens, the real germs assigned to do the dirty, deadly deed.

As this entire sordid drama plays itself out at the microscopic level, invisible to the naked human eye, a certain leap of faith is required on the part of the gardener, that the soluble, spongy medium, purchased at not insignificant financial cost over the internet, does in fact yield a viable suspension of organic pest control and not just a worthless, time consuming, crock of gunk. Taking anything on trust is not an easy ask of a long-confirmed, cynical atheist but the stoic in me hopes and wants to believe that this might just work because if it doesn’t I’ll have no strawberry patch left.

There exists no bias-free analysis in judging the kinds of life form we label as pests. We each mark our own lines and smudge them to suit. For this gardener, whole strawberry plants lost to root-decimating vine weevil larvae is crime enough to send in the coup-de-cavalry.

Strawberries, blueberries, blackberries and any other kind of berry lost to the birds, on the other hand, I deem absolutely fair play. A shiny, jet blackbird, hopping to meet his mate, through the alpines, with his juicy, multi-seeded prize held high, is a perfect joy to behold. And I marvel almost incredulously that the seed-sated, plump pigeon dozing off in the bird bath owes his precarious existence to adaptively shrinking, Cretaceous therapods that somehow survived the meteoric devastation of the fifth extinction. How on Earth?

Gardening, at root, is an aesthetic – and therefore largely subjective – endeavour. The irony of the atheist playing God in her own slice of Earthly paradise is not lost on me and the pest paradox is certainly a troublesome one. The trap of self-righteousness is one the organic gardener can easily slip into, albeit with a bucketful of best intentions, because it’s more than a little disquieting to have to honestly admit to oneself that fundamental ethical questions pertaining to life and death in the garden are still ultimately answered by personal predilections as to what is – or isn’t – pretty.