One thing that all gardeners admire is a nicely-turned plot of soil. They yearn to plunge their fingers into fluffy loam; they love to scratch long, straight furrows through pulverised dirt so they can plant all those seeds they purchased from their favourite catalogs. Truth be told, most gardeners (if they were certain no one was watching) would probably shed their clothes and wallow in the stuff.
A tilled garden is a badge of accomplishment. That patch of dark, raw earth shows the neighbors that an expert is at work. Every time a new year comes around, gardeners can hardly wait until the snow retreats so they can fire up their multi-tined mechanical beasts and roll the soil over.
But they may be doing more harm than good.
While it is probably worth cultivating those specific areas where crops will be sown, there are some good reasons to limit the amount of soil one disturbs in the zeal to dig from horizon to horizon:
Tilling may actually encourage the growth of weeds in a garden
Weed seeds in deeply-worked soils survive longer than those in shallowly-worked plots. The more soil that gets turned upside down, the larger the number of dormant weed seeds that rise to the surface…where they germinate and grow. Some weed seeds can survive for decades—and possibly centuries—under the soil. It’s reasonable to leave them there.
Soil is a complex, multi-layered ecosystem
Soil is an interdependent blend of living and non-living matter. Mixing it up is akin to sending a fleet of bulldozers through a rainforest; it takes a long time for natural processes to reestablish some semblance of order.
Deep tilling can spread pathogens and pests
Symphylans, small soil arthropods that feed on and injure the roots of many crops, get distributed more deeply in tilled soil, thus expanding their potential range for damage. While some scientists feel tilling reduces the numbers of symphylans, newer studies show that these pests feed on fungal strands in soil (as well as the roots of plants); tilling destroys those fungal strands. Without the fungi to eat, symphylans turn to crops’ roots instead. Why not hedge one’s bets, and till only those areas that will be planted?
Roto-tilling is not a green practice
Lawnmower and roto-tiller engines are notorious air polluters (and they’re usually pretty noisy, too). The longer they spend sputtering around in yards and gardens, the more obnoxious belching they do. And, with the price of gasoline reaching astronomical heights, why would anyone want to burn a single teaspoon more fuel than is absolutely necessary?
Roto-tillers are not user-friendly
Even the best-designed tiller is going to grab some rocks and roots along the way. Anyone who has been dragged behind a tiller when it encounters an immovable part of the planet knows the sensation of suddenly parting with their upper extremities. Add to that the numbness that persists in one’s hands after a few hours of chasing a tiller around a large garden, and a sensible person gets the message: The less time spent attached to a tiller, the better.
As more Americans strive to augment their menus with home gardens, and as experienced gardeners become more responsible stewards of the earth beneath their feet, they might all do well to consider this advice:
Thinking of tilling your whole garden again this year? Don’t do it!