Raising soil

“To forget how to dig the earth and to tend the soil is to forget ourselves.”

— Mohandas Gandhi

For me, the most fulfilling part of organic gardening is creating soil that can produce fruitful harvests. Although I prefer tending to digging, gardening keeps me in touch with my physical dependence on soil as the source of almost all my food — and with nature’s mysterious cycles, in which life springs endlessly out of death.

My most intensive focus on soil comes in autumn, when I begin to clean up, shape up and fertilize my 350 square feet of raised garden plots. After gathering whatever soil has gravitated to the garden paths and shoveling it back onto the beds, I add composted leaf mulch and freshly harvested comfrey leaves. These I sprinkle generously with alfalfa meal (to supply nitrogen) and corn meal (as worm food) and, every few years, with a little rock phosphate. A hay mulch protects everything over the winter.

When spring arrives, I simply pull back what’s left of the mulch from a bed, shape it so the sides slope slightly, mulch the sides, flatten and smooth the top with a rake, let the sun warm and dry the soil for a few days, then pop in seeds or seedlings. Every one of my raised beds is also a nursery for baby worms and an incubator for microorganisms that I want to disturb as little as possible, in spring or any other time. This was a principal reason I chose the ancient “mound” style of gardening — as Chinese farmers call it — for my own garden.

Raised beds provide good drainage and superior aeration. And because the raised mound is constantly enriched with organic matter, it takes just a few years to produce soil the texture of cake flour. Raised beds save labor, space and money and result in better yields than flat-row planting. The only disadvantage I’ve ever heard about them is that they tend to dry out faster, but a year-round mulch easily takes care of that situation. It’s a perfect system for a small, organic home garden.

But the hardest thing I’ve ever done in my garden was to double-dig my first three raised beds — on 24-square-foot, never-before-tilled, weed-covered clay sites. All my research had recommended this as the ideal method for creating raised mounds. I got rid of the weeds, double-dug 2-foot-deep, rectangular holes 24 square feet in area, then filled the holes back up with peat, greensand, rock phosphate, leaf mulch and the various sized clods of clay that I’d just dug out! It was hard, heavy labor that took a long time, tortured my lower back, and diluted my initial attraction to raised-bed gardening. It seemed ironic that a system that sought to follow nature’s model of growing plants with minimal disturbance of the earth’s delicate ecosystems should begin with such an invasive procedure.

Creating my first compost pile also seemed to involve way too much hauling and turning for a small woman with limited upper-body strength and a full-time job that required being on her feet for prolonged periods of time. I even considered throwing in the trowel. Fortunately, that same year I met a veteran organic gardener who was successfully growing lettuce on top of half-composted hay bales covered with a few shovelfuls of good garden soil. This inspired me to forget double digging — to forget digging, period — and fired my imagination with visions of making modified compost mounds right where I wanted raised beds in the garden. For the past 15 years, I’ve added a mound a year — none contained in wood or stone. Packaging a bed is an unnecessary waste of money, resources and labor. For years, people used pressurized lumber to contain beds, because it resists rot. But that’s because it’s heavily treated with arsenic, which poisons both the soil and any food grown in it.

My mound building begins with measuring and staking out a bed. You won’t find many classic 4-by-8-foot rectangles in my garden. Some mounds are round; some curve this way and that. This year’s bed-in-progress is a good example. About 20 feet long and 2.5 feet wide, it parallels a rectangular mound and curves around one end of it. “More like a snake than a bed,” observes my gardener/granddaughter Ivy Rose. These days, the new mounds I make are about 8 square feet bigger than what I need for planting. I use this extra space to hold compost for covering broadcast seed and tossing into planting holes. Since I’m constantly adding organic material to the beds, my need for compost is minimal.

After outlining the bed with a few stakes, I dig up the weeds in the mound area with my grandmother-sized, lightweight pick, leaving this green manure where it falls. Ivy Rose especially approved of all the plantain I uprooted and left to decompose in the new bed this year. “It will add calcium and magnesium to the soil,” she informed me. “It’s a beneficial weed.”

Next I cover the weeds with 3 or 4 inches of well-composted leaf mulch from our local leaf dump, then sprinkle on organic corn meal to attract worms. The next layer is 3 or 4 inches of dried hay for a total of 6-8 inches of carbon. On top of all that I heap a similar amount of fresh, “hot” nitrogenous material: big, succulent comfrey leaves, kitchen garbage, alfalfa meal, and weeds with lots of dirt still clinging to their roots. Throughout the summer and fall, I repeat all these layers at a leisurely pace, sheeting each layer with good garden soil. And during this process, the mound never heats up: I don’t want to kill or drive away the decomposers living in it. For the same reason, I never turn the mound, though every now and then I poke a long, sharply pointed pole in here and there and rock it back and forth to aerate the pile.

By the time I shut down the garden for winter, the mound is at least 3 feet high and one-third composted. I finish it off with hay mulch and give the microorganisms, worms and weather five or six months to mellow and meld the organic materials.

Early the next summer, I rake off the hay and use a hoe and spade to shape the mound, making it about 6 inches high and about a foot wider at the bottom than the top, with gently sloping sides. I flatten and smooth the top. To add nitrogen to the bed, I plant beans in it the first year and fertilize them with wood ashes to raise the pH. After that, the new bed is treated like all the others.

The complex interactions of the minerals, dead stuff, water, solar energy, gases and multitudes of life forms (most of them invisible) that create fertile soil are mind-boggling. I feel privileged that organic, raised-bed gardening has helped me learn even a little bit about them. And deepening my understanding of the soil’s unending eco-dances keeps me connected with the primary energies of life: growth, death, decay and rebirth.