“You have to be a scientist!” the woman at the garden centre exclaimed on learning how to apply nematodes to control white grubs on the lawn.
Most gardeners, as opposed to garden-owning householders, consider themselves something of naturalists also. But scientists, let alone ecologists, biologists, entomologists, mycologists, pathologists, climatologists and numerous other exotic experts?
Yet it is rapidly becoming necessary to have at least a smattering of these sciences to undertake pest, disease and weed control in the home garden, particularly now many jurisdictions have banned the dreaded “cosmetic” chemicals of days gone by.
The temptation to substitute a homemade solution to an immediate problem is almost overwhelmingly tempting. But hold on a moment there before launching your own personal
blitzkrieg.
Most home brews are, like their now banned chemical counterparts, broad-spectrum eradicators. That is, they wipe out almost all insect and other arthropod life, friend and foe alike. Often when an insect pest is first noticed, its nemesis is not far behind, unnoticed to the untrained eye. And it is often another bug.
Although not an insect, but an arachnid, spider mites are the bane of gardeners outside and indoors. Under warm dry conditions these minute pests cause leaves to take on a dusty appearance, fine webs appear in the axils, and the foliage yellows and falls. Eventually the plants succumb. Some control may be gained with insecticidal soap. Unfortunately this also kills the spider mites’ principle predator, another spider mite only slightly larger than its prey.
How about beetles, ants, snails and other creepy-crawlies? Something called diatomaceous earth is often recommended. The fossilized skeletons of marine and freshwater diatoms, it feels like talcum powder to human hands. Under the microscope, it is revealed to have jagged edges to rip and tear at any bug unfortunate enough to crawl through it. And that’s the problem:
any bug, bad and good alike. Diatomaceous earth will take care of ants, snails, cockroaches – along with ladybugs and centipedes. But it won’t state that on the container.
Wasp traps that drown the buzzing beasts work just fine. Yellow jackets arrived here from Europe in the 1920s. Unlike their cousins the honeybee, they can sting repeatedly. They need this power to subdue the insects they feast on in late spring through until midsummer. Then they start stoking up on sugars from fruit and, inevitably, drinks left lying around. So these hawks of the insect world are both good and bad guys depending on the time of year.
Other much more minute wasps parasitize caterpillars, aphids and other pests by laying their eggs on or in them. When the larvae hatch, they commence to gruesomely feast on their host, eventually killing it. Spray with a home brew insecticide and, again you’ll likely kill such beneficial insects.
You may not have to be a scientist but the lesson from all this is not to reach for a handy spray, chemical or organic, at the first sight of an intruder. In days gone by before pesticides proliferated, older gardeners tell tales of a remarkable pair of pest control devices. Located at the ends of the hands they are called fingers. A pinch, a squelch – no more bug. Better yet, in its demise many a bug releases an odour warning its relations to scram.
Anything else? If you can’t beat them, eat them suggest some gardeners. Pluck the pest and . . . munch, munch, munch. Oops, don’t let PETA catch you, though; they oppose noshing on live insects. “Insects do not deserve to be eaten alive especially for a gratuitous marketing gimmick,” says PETA spokeswoman Jackie Vergerio.
