No-Dig Gardening

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By Charlie Nardozzi

One of my revelations as a gardener has been to pay more attention to the soil. I grew up in a shadow of my Italian grandfather's farm where tractors, tillers, and plows ruled the day. Turning and tilling the soil was just how farming was done. But as an adult I started questioning the need for all this tilling, especially on a home garden scale. I started learning the downsides of tilling. Tilling and turning the soil brings up weed seeds that germinate and make for more work during the growing season. Turning the soil also disrupts the natural layering of the soil where air and water spaces thrive along with soil microorganisms and creatures. These organisms and the soil structure are critical to growing healthy plants. If left in place the soil becomes more productive and less likely to erode from winds and rain. By simply adding organic materials each year on top of the garden you can build the fertility of the soil without having to dig the materials into the soil. Plus, no dig helps in a small way with reducing global warming. The less you dig, the slower the organic materials break down releasing carbon dioxide into the atmosphere.

Simple No-Dig Gardens

I've been no-dig gardening for awhile now and see how much less work it is and more productive my vegetables and flowers have become. Many gardeners already use no-dig techniques when building and planting raised beds. Gardeners know how to make wood, stone or free standing raised beds at least 10 inches deep right on top of the lawn or garden surface. Fill the bed with a 50:50 mix of topsoil and compost and you can plant right into the bed. It's that simple!

The main difference with no dig gardening comes in the maintenance of the beds. Maintain the bed by adding a 2- to 3-inch thick layer of compost before every planting, but don't dig it in. After the garden season is finished instead of pulling up the plants, chop and drop them. Use a hand pruner or hedge trimmer to cut off the plants at the ground level. Then chop them into smaller pieces and leave them in the garden to decompose. This adds organic matter that will break down into compost without disturbing the soil and provides some winter protection. Only remove plants if they were heavily diseased or insect ridden.

Multi-Layered No Dig Gardens

Another way to create a no-dig garden is to build layers of organic matter. This reduces the amount of compost and topsoil you need to bring in. If done properly you'll be able to plant in that bed while the organic materials are breaking down. There are many recipes to use in making a multi-layered bed. The simplest is to add 4 to 6 layers of wetted newspaper over your lawn or garden area to kill the grass and weeds, and preserve the rich soil underneath the lawn, before you start layering. If you have perennial weeds, such as brambles and quack grass, add a thick layer cardboard instead of newspaper. No dig methods eliminate the need for any digging so you save your back while building a healthy garden soil. Then add 6 to 8 inches of hay or straw mulch and 2 to 3 inches of compost. We've used this simple lasagna garden technique to expand and build new beds.

More involved recipes mix in a variety of materials. Add 3 to 4 inch thick layers of high carbon (brown) materials such as hay, straw or chopped leaves, with layers of high nitrogen (green) materials such as fresh grass clippings from untreated lawns, plants without seed heads or roots, seaweed, vegetable table scraps, and compost. I try to use materials that are naturally around my environment when creating layers. Keep layering until you reach the top of the bed and cap the bed with a layer of compost. If building the bed now for planting this year, shred the organic materials before layering so they break down faster and make the top compost layer 3 to 4 inches thick for planting. Otherwise, let the materials naturally decompose for a few months before planting.

Once built and growing, keep the soil mulched with grass clippings, straw or chopped leaves to preserve moisture, keep weeds away and continue building the organic matter in the soil. I've also been experimenting with living mulches around large vegetables such as tomatoes and squash. I sow mixed greens, such as lettuce, kale, Swiss chard, collards, bok choi and basil around the plants and let them fill in between the larger veggies. The idea is you'll get an extra harvest of greens, plus the greens will encourage more soil biological activity making it healthier for your plants. Some gardeners say this green cover crop reduces insect and disease problems as well. Stay tuned and I'll be giving you updates.

So give no-dig gardening a try. I've written a new book on the topic called The Complete Guide to No-Dig Gardening that offers lots of tips and techniques.