Farming is making headlines as a tool for mitigating climate change. By using farming practices that restore and rebuild soil, farmers can draw down excess carbon from the atmosphere and sequester it in the soil.
But what about those of us who live in urban or suburban areas? Are we once again just bystanders to a promising climate solution?
Of course not! We can become urban carbon farmers!
Even if you only have access to land in the form of a postage stamp-sized backyard, you can start caring for that land in a way that stores more carbon in the soil. If you live in an apartment and have no yard, you can join a community garden or participate in creating urban food forests in your community.
True, urban and suburban folks can’t implement large-scale carbon farming projects of hundreds or thousands of acres. But the cumulative impact could be huge. In the US alone, we have over 40 million acres of lawn, and who knows how many more acres of home vegetable gardens and landscaped yards. Add to that the conventionally landscaped public parks and green spaces. Imagine the potential if we could transform how all of that land is managed!
Here are some tips for starting to “farm” carbon in your own garden. Contrary to what you may think, some of these gardening techniques may actually be a lot less work: no-till gardening is sometimes called “gardening for lazy people.”
1. Minimize tilling and digging
We dig this method — metaphorically, of course. Heavy tilling destroys the soil’s structure and the soil biology that feeds plants, and contributes to erosion. Many of us imagine that you have to till in order to grow plants. But that’s not the case: check out this inspiring video of an abundant no-till garden!
If you follow the steps below, you’re giving soil fertility a continuous boost without tilling. The more you can avoid disturbing the soil and the natural layering that occurs, the better. As for aerating and loosening the soil, the broadfork is a fantastic tool for doing so without turning the soil over.
2. Heavy mulches
One of the most climate-friendly things you can do in your garden is never leave your soil bare. Mulching protects the soil, suppresses weeds, and invites in tiny gardeners’ assistants such as earthworms. Mulching materials slowly break down to create topsoil with a lot of organic matter (and that means: a lot of carbon).
You can use organic materials such as straw, wood chips, and compost to create a thick mulch, and plant right through the mulch. If starting a garden from scratch, sheet mulching is a great way to suppress weeds, invite in a lot of earthworms, and build carbon.
3. Cover crops
Another good principle: always keep a living root in the soil. In your vegetable rotations, rather than letting a garden bed lie fallow, use this time to grow a cover crop. Cover crops are crops planted primarily to suppress weeds and add more nutrients into the soil. They are also great for sequestering more carbon. Any small annual grains (wheat, rye, oats, or buckwheat) or legumes like hairy vetch, winter peas, and crimson clover will do well.
After blooming, but before it goes to seed, the cover crop is cut down or rolled down and becomes a mulch. If your garden plot is small, you can hoe down the cover crop using hand tools. If you have more land, check out this article on tools. And this great video shows a DIY, low-tech method for rolling down cover crops.
You can then plant the next crop directly into the cut-down cover crop mulch. You can plant as seeds any plants that send up strong, sturdy seedlings (think corn, squash, beans, cucumbers or melons). With flimsier plants, you’ll have better success if you transplant them as seedlings.
Compost all your food scraps and garden waste. You will not only reduce the greenhouse-gas emitting waste that ends up in the landfill, but also provide food and habitat for the bacteria, fungi and tiny critters that healthy soil needs.
6. Integrate perennials into your garden
With perennial plants such as trees and shrubs, you really don’t need to till or dig the soil. Once established, they require much less care than annuals, and all those big roots going deep into the ground and creating more forest-like habitat means greater biodiversity in your garden… and more carbon stored in the soil. The options are endless: fruit trees, berry shrubs, nut trees or shrubs, rhubarb, artichoke…
As Eric Toensmeier points out, berry shrubs are the perfect gateway plant to perennials: they’re delicious, they’re really good for you, and they’re easy to grow – many of them thrive even in shady areas. Integrate perennials and annuals within the same growing area into a multi-story, multi-species “food forest” that makes for an incredible urban carbon pump. Don’t let the word “forest” throw you off: this can be done on a small scale even on a small urban lot, with a single dwarf variety fruit tree as the centerpiece.
7. Drop all pesticides and synthetic fertilizers (if you haven’t already)
They kill soil biology. They’re harmful to your health, too. Need we say more?
8. If you insist on a lawn:
We think there are a lot more exciting things to do with your yard than a lawn: turning your lawn into food, planting a garden prettier than a lawn, or having a “natural yard” with tall, meadow-like grasses.
But if you’re one of those people who must have a lawn, follow these key principles of climate-friendly lawn care:
- Start phasing out all chemical fertilizers.
- Include non-grass plants, like clover, in your planting mix.
- When you do mow, set your mower height to at least 3” and leave the grass clippings on the lawn.