It used to be an article of faith in gardening that you must begin the whole enterprise by turning the soil, either with a shovel, spade or the frenzied paddling of the rototiller.
The rationale was that this laborious spadework brought loamy topsoil down to subsoil level to promote deep rooting, relieved soil compaction and allowed the gardener to improve sandy and clay soils by adding compost.
Garden manuals entreated beginners to "double dig," a wearying technique of inverting layers of topsoil and subsoil while amending both with organic matter. I don't know anyone who did this — double digging emanated from old English estate gardens with armies of low-paid gardeners — but the concept reminded us of our sacred duty to dig those beds.
These days, the value and orthodoxy of digging the soil is undergoing a profound re-evaluation.
Many gardeners have discovered that, by not disturbing the soil, they can grow vigorous vegetables and other plants with fewer fertilizers and a reduced need for watering and weeding. But this "no-till" gardening is not no-maintenance. It requires a continual application of organic mulch, the occasional spearing of the soil with a fork and a capacity for patience. It can take three or four years for the microbial life to build up in the soil and the worms and other creatures to incorporate the organic matter and airways into the subsoil.
I am a traditionalist and am wary of no-till practices, but I'm coming around to the advantages, particularly the capacity to break the cycle of weed growth. Gazillions of weed seeds lie dormant or are ready to waft in, so anytime you disturb the soil, the weeds germinate and take over. The warmth and moisture of the Mid-Atlantic have made this region weed central, so weeding here is an eternal chore.
NO-TILL GAINS TRACTION
From my own plot at the Glover Park Community Garden in Washington, I have observed Teresa Savarino, her husband, Omar Hopkins, and their daughter, Sylvia, 14, fully embrace the no-till approach over the past few years. They have cranked it up to a level called permaculture, where the soil fertility is maintained without any feeds, even organic ones. Much of their seed comes from their own plants, as they seek to "close the loop."
Soil fertility is achieved by burying shredded kitchen scraps under thick blankets of straw to compost in place. This can be a tricky approach in the city, where rodents are abundant, but the family is vegetarian bordering on vegan, so the scraps contain no meat, eggs, dairy or oils, and they are finely chopped and deeply buried under the straw.
A typical gardener here is hard-pressed to use up a single bale of straw each growing season. Savarino, by contrast, goes through about 20 bales a year. She constantly spreads it on growing beds and paths alike, and she plants or sows through it with minimal soil disturbance.
With summer in full swing, the garden looks replete, healthy and fruitful, displaying a convergence of spring and summer crops: cabbage, kale, summer and winter squash, and plenty of tomato plants, peppers and eggplants. Savarino showed me a fennel plant that had produced a broad, white bulb; this is hard to achieve in warm climates such as ours, and you have to wonder whether this is a product of no-till practices.
The family has had the plot since 2005, but they switched to no-till gardening five years ago. "It's supposed to come into its own in the fourth year, and that seemed to be the case for us last year," Savarino said. "We just had wild growth."
Over time, the worms and other soil creatures draw down the organic matter, and their tunnels aerate the soil (along with the regular subterranean forking). This and the thick straw layer mitigate the compacting action of rain and snow. No-till advocates say another plus is that the strands of beneficial fungal mycelium are left intact. These fungi have a symbiotic relationship with plants, extending their nutrient uptake and disease resistance.
INSPIRED BY RUTH
Savarino was inspired by Ruth Stout (1884-1980), a Connecticut gardener who popularized no-till gardening in several books. She used hay as her mulch, but it can come with weed seeds. Straw is cheaper and more available, and it takes a little longer to break down. Savarino said she contacted the grower of the straw she uses, and he assured her that he had not used pesticides on the wheat it came from.
If you want your vegetable garden to resemble the groomed potager of a French chateau, no-till probably isn't for you. This is because beds are not cleared, turned and planted with discrete crops. Rather, new seed is sown or transplants are inserted as plants are harvested, so the effect is much more integrated — or chaotic, depending on your viewpoint. "It's a jumble," Hopkins said. Navigating path and bed "is like a game of Twister," Savarino said.
The couple said that, since they have switched to no-till, they have grown more food with fewer insect pests, and have had less need to water and less weed pressure. Most of their weeding is for wiregrass and a bulbing aroid named pinellia, which can double its number every year.
Overall, the no-till approach means thinking anew about how to garden. This is not necessarily easy for a seasoned, orthodox gardener, but the reward is a system that, once established, requires less work. After heavy rains, for example, my soil crusts, and I have to break it up with a cultivator or knife while avoiding seedlings. In permaculture, though, the thick layer of mulch negates this need. Sylvia has picked up on this distinction. "For me, it's been less about the work aspect and more about how different it is from the gardens around us," she said.
The family said the amount of its kitchen scraps going into the garbage is now a third of what it once was.
PROPAGATING PERENNIALS
About a mile to the north, in the Newark Street Community Garden, I met Marguerite Pridgen at her no-till plot. Looking at her garden sage amid summer vegetables, it became clear that, in this system, you can grow perennials cheek by jowl with annuals in a way you can't in a garden where the beds are continually disturbed. "I have more and more herbs that are perennial," she said. This palette of perennials might also extend to strawberries, horseradish, lovage and asparagus.
"For the first two years, I struggled with getting it where I wanted," she said. But now, 10 years on, "the soil is so fluffy, I really don't have to add anything to it."
New gardeners arrive and become overwhelmed by the relentlessness of weeds, she said, especially after a summer vacation or longer hiatus. "It's one of the main reasons for the turnover" of gardeners, she said. Pridgen uses cover crops to block weeds and feed the soil; daikon radishes work to open up the soil without digging, and legumes, such as vetch and clover, add nitrogen to the soil. "I have had a lot of good harvests over the years," she said.
At Lederer Gardens, a communal farm and community garden in Northeast Washington, the gardeners have initiated a no-till system this year. Rows 100 feet long and more than three feet wide rise amid earthen aisles, and the beds are now full of tomatoes, winter squash, corn, okra and bush beans. In one stretch, strawberry plants act as a ground cover between collard greens.
To create the garden, the old beds were cultivated down 12 inches with a heavy steel tool named a broadfork — essentially an implement with curving tines between two tall handles. The tool is pressed into the ground with your foot, then rocked back and forth, opening the soil without disturbing the surface. The beds were then raised another 12 inches with a mix of topsoil and compost.
Before the new system was put in place, the garden had a problem with chronic flooding, which ruined crops. New drains have helped fix that, but so, too, has the switch to a no-till system, said Josh Singer, community garden specialist with D.C.'s Department of Parks and Recreation.
Previously, gardeners used rototillers, which would produce a fluffy soil on top but, after 50 years of tilling, created a hardpan clay beneath. "Getting away from tilling has done so much to absorb the water," he said.