The health and vitality of soil everywhere, from the smallest backyard garden to the largest Midwestern farm, plays an integral role in food production – and it’s threatened by the climate crisis.
The story of climate change’s impact on soil health is really a tale of water. Extreme downpours can lead to runoff and erosion because the ground simply isn’t able to absorb the precipitation at the rate it’s falling, stripping healthy soil of key nutrients needed to sustain agriculture. On the other end of the spectrum, frequent droughts and enhanced evaporation from rising temperatures are not only killing off the vital living soil ecosystems necessary to grow healthy crops, they’re also leaving less water to dilute even relatively common pollutants in reservoirs, streams and rivers, lakes, and wells.
So what can you do about it? Plenty, it turns out – and you can get started without leaving your own backyard. By simply rethinking how you garden, you can do your part to fight the climate crisis.
Get your garden ready for spring the sustainable way by starting a raised lasagna garden instead of traditional in-the-ground bed.
But wait, what’s a “lasagna garden”? We’re glad you asked.
Lasagna gardening is a cold composting method where alternating layers of carbon and nitrogen materials are placed directly on the soil. With carbon materials, you want to think green, like vegetable scraps, peat moss, or fresh lawn clippings; while your nitrogen materials are going to skew brown, like straw, coffee grounds, or dry leaves.
It’s best to lay down the layers several months before you want to use the planting area, making fall an ideal time to get started. The materials break down slowly over the winter, so your garden will be ready for planting in the spring.
There are many benefits to sheet composting. It’s easy and uncomplicated, and can be done a little at a time on a large or small scale. It’s a great way to convert grass to vegetable beds or enlarge an existing garden with a minimum amount of equipment, material, and time. And best of all, it’s great for Mother Earth: By lasagna gardening, you’re improving soil and soil structure and recycling organic material, all while creating a carbon sink that works for you by producing nutrient-rich, healthy homegrown food.
Here’s how to get started:
1. Build a raised-bed frame (if you want): A frame is not essential to lasagna gardening, and may not be practical if you are planning on a building out very large vegetable bed. But it will help you manage a smaller plot – and add to the appearance of your garden. The dimensions can vary to fit your space, but the frame should be at least three feet high to provide the depth needed for the alternating layers. Be sure to use non-pressure-treated lumber.
2. Mark the length and width of your bed and mow the grass or other vegetation down to the lowest possible level.
3. Loosen (but do not till or overturn!) the soil underneath the bed with a spading fork or similar tool to make sure there is good drainage for your raised bed. And make sure you remove any pernicious weeds while you are at it.
4. Now, lay down your base. The Brooklyn Botanical Garden recommends beginning “with a layer of cardboard on the bottom of the bed, which will break down very slowly as it smothers weeds and soaks up moisture. Chop up some twigs, small branches, or hedge trimmings [carbon base layer] into one-inch pieces and layer them four inches thick over the cardboard—this will provide good drainage for the bed.”
5. Begin adding layers. From this point, alternate layers of nitrogen material and carbon material, watering the layers as you go. As with all compost, a lasagna garden needs a properly proportioned mix of carbon, nitrogen, oxygen, and water to break down the organic materials into a good growing medium.
6. Continue adding layers. Repeat the layers described above – nitrogen layers of material like used coffee grounds, straw, or compost, and carbon layers of material like leaves, peat moss, and fresh weeds – until the bed is full. Remember to always end with a carbon layer and thoroughly water a final time.
7. Leave it to decompose. Good compost takes time.
And that’s it!
Come spring, you’ll notice the bed will have shrunk down, so you may want to incorporate a four-to-six-inch layer of top soil before you start planting. After you’ve harvested the last of your vegetables in fall, prepare for the following year’s planting by simply adding additional, alternating carbon/nitrogen layers to the top of the bed. Taking climate action doesn’t get much simpler than that.
Learn more about the relationship between climate change and declining soil health, the threat it poses to food security around the world, and the potential climate solutions found in practices by downloading our free new e-book, Right Under Your Feet: Soil Health and the Climate Crisis.
A global challenge needs a global solution. Wherever you are, whatever you do, no matter the time you have, you can do something right now to bring us one step closer to a future without carbon pollution. One where we can provide our booming world population with fresh, healthy food grown in a sustainable soil ecosystem.