The deeper into gardening you get, the more you see that you are really growing soil — which is a crucial carbon reservoir.
By Leah C. Stokes – December 27, 2020
Between the coronavirus and the election, 2020 blurred together in a haze of stress. But for the huge number of people who took up gardening this year, the seasons did not just slip by: They were measured in inches of plant growth.
In the spring, some seed companies saw sales spike up to 10 times normal. The 144-year-old company Burpee had a record year. Like weeds growing up through cracks in pavement, this trend was a reminder of all the ways life continues.
People used whatever materials and space they had to spare: old drawers for planter boxes, narrow balconies for salad crops. Others went beyond their backyards, setting up garden plots for their neighbors or doing their own gardening elsewhere in their community. Some made homes for pollinators, to support their other neighbors: bees, birds, and yes, even those dreaded squirrels and gophers.
Gardening gives us another way of living with the earth. Robin Wall Kimmerer — an indigenous ecologist whose books sold almost as well as seeds this year — writes beautifully about the potential for people to contribute to, rather than only damage, ecosystems. When she asked her students to describe a positive relationship people have with the planet, a majority could not think of any example. Whether it’s climate change, plastic pollution, or the biodiversity crisis, it’s easy to feel as if we humans are all harm and no healing.RELATED: Ideas: The power of urban farming
But for those who took to the garden this year, we saw that another world is possible. And it starts with the soil.
That’s the first thing any budding gardener hears: Pay attention to the soil. It feels like a koan. For a while, most will fail to grasp its meaning. And with guides full of to-do lists, it may seem like just another thing to think about.
Many books will tell you all about “double digging” — the practice of digging a garden bed several feet deep, to loosen the soil. I tried this method at first: raising the soil up and turning it over to break up the hard clay. Mostly it will break your back. It reminded me of the young adult novel “Holes,” in which kids dig a hole every day as punishment. This approach makes gardening more like army training than the light exercise you’re probably looking for.
But the deeper into gardening you get, the more you see that you are growing soil more than plants. Like feeding your gut to feed your body, adding compost on top of your garden feeds the land. In most cases, there’s no need to dig.
Recently, I started following the work of Charles Dowding, a British gardener who advocates for “no dig.” At his plot called Homeacres, he has run experiments that demonstrate that adding compost on top of soil, rather than digging it in, leads to higher yields. The approach involves laying down flattened cardboard boxes, to suppress the weeds, and adding generous amounts of compost on top. Your goal is to feed the soil under the cardboard without disrupting its structure — over time, your patch of dirt will spring to life, drawing nutrients downward from the compost. This also gives you something useful to do with the boxes you’ve accumulated from home delivery. All that cardboard? It’s made out of carbon, which you might be able to store in the soil.
I began my gardening year with a city mulch delivery to my community garden plot and many trips to a nearby horse stable. I was already a gardener and composter, but I too found my ambitions growing under quarantine and wanted to try large-scale composting. Using leaves, mulch, manure, and a touch of seaweed, I turned three-foot piles weekly. In a couple of months, I had homemade compost, which I used both to fill new beds and to add on top of my existing garden. The results were astounding. In just a month, my seedlings exploded.
This fall, I took over a second, neglected community garden plot. This time, digging was necessary because a healthy gopher population required me to lay down wire. So I tried hügelkultur: the practice of burying wood, leaves, and other biomass in the soil, where it slowly decomposes over years. In addition to storing carbon, the sticks and logs also store water: as they break down, they become sponges. For the regions of the country becoming more drought-prone due to climate change, this approach could be transformative.
These practices are the backyard versions of a broader movement: regenerative agriculture. The idea is to improve landscapes by trapping carbon in the topsoil, holding water, and increasing biodiversity. When plants grow in healthy soils, their roots work with microbes to bury carbon. If this soil is left undisturbed — for example, if it is not tilled — it can hold more carbon. Increasing these practices could, optimistically, compensate for 10 percent of the United States’ annual carbon emissions.
That said, this is not a silver bullet for the climate crisis. Scaling up these practices in farms and backyards across the country will be challenging. And it’s important to remember that soil carbon storage is not the same thing as geological storage. When we dig up fossil fuels, we are bringing carbon up from deep underground. If we put it back in topsoils, it can easily escape to the atmosphere if the soil is disturbed through tillage or wildfires. Putting carbon in the soil is like putting a box of money under your bed, rather than in a bank vault: it’s much more likely to disappear.
Gardening can even exacerbate our carbon problems. Right now, many Americans are buying bagged soil mixes that contain peat moss. Sphagnum peat moss grows in giant bogs in Canada and other parts of the world. These peatlands are carbon storage engines: They cover just 3 percent of the earth’s surface, yet they store 30 percent of our soil carbon. That’s twice as much as all our forests. The plants grow very slowly, making them more like a fossil fuel than a renewable resource. Yet we are harvesting these carbon sinks to fluff up our garden soils.
In the United Kingdom, there is a well-established movement to boycott peat moss. But in the United States, it’s still in most soil mixes. Buying peat is like digging up coal to put it in your garden. For my part, I’ve started scouring potting-mix labels to find options without peat and mixing compost with rice hulls to start my seeds.
This year’s gardening trend could be like a seed: the beginning of something much bigger.
Stuck at home, so many people have changed how they live: spending more time in nature, more time on a bicycle, more time in the garden. The few times I met up with friends this year, we went to gardens and parks. If this increasing connection with our environment continues, it might help wake people up to the climate crisis on our doorstep.
This dark year is now drawing to a close. As gardeners know, the season of New Year’s resolutions is also seed catalog season. So if you missed the 2020 gardening blitz, now is the perfect time to set an intention for 2021. Your soil and our planet will thank you.
Leah C. Stokes, an assistant professor of political science at the University of California, Santa Barbara, is the author of “Short Circuiting Policy,” a contributor to the essay collection “All We Can Save,” and co-host of the podcast “A Matter of Degrees.” Follow her on Twitter @leahstokes.