On consideration of dirt

I’ve been doing a lot of gardening recently, probably more than at any other time of my life except when my spouse and I bought our first house nearly twenty years ago and thought we’d become avid gardeners like both of our mothers. Between the heavy clay soil, ubiquitous thistles, poison ivy, and—once a friend of ours trained her lawnmowing goats in our yard and brought her horses by a few times—mile-a-minute vine, it was far more laborious and less fruitful than we’d hoped. Later, when we’d scaled back our ambition and built a few raised boxes filled with bags of soil purchased from Home Depot, the seeds of a perennial sunflower we’d planted took over and made itself into an impenetrable (if pretty) autumn jungle; aside from a small effort at tomatoes every year we gave up. I probably could have handled the labor but the heat and humidity of upstate New York did me in.

I’ve been promising our kids a garden ever since we moved back to Montana, somewhere they could grow carrots, berries, and pumpkins, but gardens are work, our summers are short, and the soil of our yard turned out to be a thick gumbo-like substance similar to the clay we had in New York. I was digging rows for potatoes last weekend and each forkful brought up a heavy mass that was less “dirt” and more a soil-like clod of slick glue riddled with thistle roots and (thankfully) worms. Breaking each chunk apart by hand showed strata and fracture lines that reminded me of shearing lava rocks when I was little. Left long enough, this soil, too, might eventually compress into solid rock.

A neighbor friend was working at a tree trimming service last year, and dumped truckloads of mulch on the garden throughout the summer, which seemed like a useful thing until a friend pointed out that most of the trimmings were cedar, and cedar leaches nitrogen from soil. Which meant we’d have to add nitrogen in the form of other soil, compost, and, in the long term, nitrogen-fixing plants like lentils or vetch.

Gardening seems to require purchasing soil or compost anyway, which was really odd to me once I started thinking about it. My mother never bought soil when I was growing up, and she cultivated bountiful gardens in nearly every house we lived in, even ones we only rented for a year. In one, we spent only one summer but had the largest, sweetest strawberries in my memory. The house was in a sheltered hollow an hour or so south of where I live now, and the soil, as I planted carrot and pea seeds under her instruction, was loamy and soft, at least eight inches of enriched glacial silt.

It’s hard to grow things in clay soil. Fruit and vegetable roots struggle to wind through thick compacted dirt, no matter how much nutrition it holds. I dug a row to grow tomatoes and peppers last year, just to get something in the ground after we fenced in an area during lockdown, and they grew sparse and yellowish, producing very little. This year, my buddy who’s been gardening most of his life told us to go down to the place on the south end of Flathead Lake that sells peat mixed with compost to till through the soil, feeding it while breaking it up. I nixed the tilling part because every time I dig in this area of the yard I bring up some substantial object, like a hammer or a kitchen knife or a length of pipe or chunk of brick. I didn’t know what a previous owner used to do here but it wasn’t gardening. (Unless they were gardening snips of wiring because I’ve found hundreds of those.) In our last yard we’d used a tiller in the garden and ended up nearly wrecking it because the soil there had good-sized rocks seeded all throughout the clay, and sometimes a large one would get stuck in the tiller’s blades. It’s an expensive mistake to assume your dirt contains only dirt.

I haven’t gone to pick up a cube of peat because I have to get my truck’s oil leak fixed first, but the whole idea of it has given me pause—to enough to not do it, but I’ve been thinking a lot about peat and topsoil and where it all comes from. I’ve bought about twenty bags of gardening soil from the hardware store in the last month, piling beds on top of hand-dug clay, and each time I haul out and rip open that forty pounds of plastic-wrapped dirt, I have to wonder about its origins. Unlike, say, trees, soil isn’t precisely a renewable resource. It’s not something you can extract and then plant again. Pretty much all of our life depends on soil, yet it’s not something we’ve really learned to make. Make up for the lack of, yes, sometimes, but not make, at least not fast or at scale.

Making soil is in essence what compost is. We take organic materials—banana peels, chicken bones, supposedly compostable plastic bags or parchment paper—pile them up to promote the creation of heat, add worms or enzymes or nothing, and wait. Given enough heat and time, the materials turn into something that can then be used for the eventual creation of tomatoes. It’s rich and effective, but is it soil? Soil at its most unmolested contains worlds that we’ve barely begun to understand, microbes and bugs and interlocked roots and mycelial networks that leave researchers wondering where mushrooms end and fungi begin.

(It’s all connected. Pause for a minute and really, truly think about that. Every single speck of existence, connected. I know it’s been said in numerous wonderful ways but it’s always worth letting yourself sink into the knowledge.)

I recently finished Charlotte Gill’s book Eating Dirt about her years working on a tree-planting crew. It came recommended from science writer and former Arctic researcher Sarah Boon, who shared enticing excerpts, but I wasn’t really sure what to expect. I’ve read so many books about trees!

Whatever I expected, Eating Dirt turned out to be different from that. More. Deeper. Fuller. I told Sarah and our little group of science writer friends that it had been a long time since a book actively felt like it was slowing my mind down. Pulling me down into the dirt and getting this jumpy, too-inattentive mind of mine to settle down and enrich itself with light but held attention. Despite the fact that Gill frequently describes the speed of the work itself, as the planters are paid so many cents per seedling in the ground, the effect of her language was exactly the drawdown I look for in mindfulness practices and bonfires and books and slow walks in the woods by myself.

It was like being furrowed by a gentle hand reminding me of the richness that each of us contains in our selfs. And at the same time she refocused me on the soil as I read, since Eating Dirt made me think about dirt and soil far more than it made me think about trees:

“Even now, old-growth soil is ancient and alchemical. A world beneath our feet that’s oceanic in its unknown fecundity. Crustaceans live in it. Out of this dark fundament, life is born of inert matter, from rocks and clay and sand. Trees germinate here: light-drinking organisms that suck molecules from the air and transform them into a wondrous polymer, which is both strong and flexible. And when they are done living they disassemble and return to the earth. Dust to dust.”

The area we lived in New York is a big agricultural region. We were surrounded by corn fields and apple orchards, and just a few miles away was some of the richest soil in America, hummus so deep that fully intact woolly mammoth fossils have been extracted from it. It’s called the Black Dirt Region, tens of thousands of acres of the remains left by the glacial lake of a previous ice age. It was until recently the source of nearly a quarter of the U.S.’s onions, and the soil is so treasured—between 30 and 90% organic matter when most soil has less than 10%—that it’s illegal to sell. (Why our yard was full of compacted clay instead is another question, though I think it had been a corn field for a long time.)

Which brings me back to the question of purchased soil, just a thing we do these days. Build some boxes, start some seeds, and go buy soil. I had a friend who ran a microgreen business for a few years, and she had to buy mountains of fresh soil for her seeds. It got reused in her larger farm, but still, she had to bring it in. And then there’s my friend’s advice to follow his lead and buy big cubes of peat to work into our clay.

Peat, as I learned when living in Scotland, is a huge carbon sink and grows at a rate of about a millimeter per year. It has to be mined or extracted and growing it back can take lifetimes. The bags of soil I buy at the hardware store are probably mixed with peat, and often with topsoil, which is also mined from somewhere else. The more I poked around in the question, the more the dependence on this shipped-in resource seemed odd, or at least odd in its inexplicability, its presentation of “here’s dirt!” without a mention of its origin, its homeland. And it’s weird that the backyard gardener even has to go looking for advice on “how do I grow vegetables just in my own dirt?”

I can make compost myself, which would feed and lighten the soil over the years, and we’re fortunate to have a composting business in the area, which picks up customers’ buckets of compostable materials and drops off bags of compost in the spring. And there’s a dairy farm a few miles away that sells the sawdust it uses in the cow stalls, which supposedly makes a good gardening addition once it’s composted itself, especially for this bulky clay soil. In other words, I have options other than cubes of peat moss or plastic bags of soil. 

Robert Macfarlane has a chapter in his book Underland in which he ventures for miles in tunnels built for the extraction of potash, an essential ingredient in agricultural fertilizer and of which there is, again, only a finite amount on the planet. I thought of that chapter, an eerie realization among many in Underland, as I was pouring soil on top of dirt over the last couple of weeks in order to plant onions and spinach, potatoes and peas, that everything we wish to do, even wholesome things, is part of a massive, often unseen, shifting of resources stripped away in one part of the planet, packaged and sent to another.

I think, maybe, while I’m trying to figure out how to eradicate thistles and knapweed and protect water and build resilient communities and narratives for an uncertain future, I’d better think more carefully about building this soil, too, without depending on extraction from elsewhere. To slow down and begin seeing dirt the way Charlotte Gill does, as something miraculous, precious, and absolutely necessary to our survival.


Bonus photo:

Hello thistles, my old friends. I’ve come to murder you again.