Duane Hovorka, Agriculture Program Director
Bare soil should be the bane of every gardener. Unprotected by mulch or growing plants, naked soil is much more prone to erosion. It also absorbs heat faster in the summer, baking the plants gardeners are trying to grow. While mulch helps protect soil from rain and heat, living mulch – that is, a dense covering of live plants – does even more to protect and feed the soil.
Healthy soil is teeming with life. Beneficial bacteria, fungi, worms, and other critters in the soil provide nutrients for garden plants and help them access water. These tiny organisms aerate soil, hold soil particles together, and help store water plants need.
Those critters need food. In many cases, growing plants provide this food by pumping carbohydrates through their roots and into the soil. But annual garden plants like tomatoes, squash, and peppers only grow a few months of the year, leaving beneficial microbes to go hungry in the winter.
That’s where cover crops come in. Planted in the early spring (and cleared away a month or two later), cover crops can improve the soil for summer vegetables. Planted after the last frost, they can prepare the soil for late summer or fall crops. Planted in the early fall, cover crops can provide protection and feed microbes over the winter and into spring.
Cover crops can boost soil health by feeding microbes, but they can also smother weeds, shade soil from the hot summer sun, and shelter and nourish pollinators and other beneficial insects.
What kinds of plants make good cover crops? The Rodale Institute suggests a combination of legumes – like clover, vetch, or peas – to fix nitrogen in the soil, alongside annual grasses or grains like rye, oats, or buckwheat. Visit the Rodale Institute to learn about many cover crop options.
Bare soil in a yard can be a sign of unhealthy soil beneath, or too much wear and tear on the soil’s surface. Planting a mix of legumes and lawn grasses, and protecting the area from over-use, will help rebuild the health of the soil.
This summer, don’t garden naked. Cover up! Continuous living cover is one part of the recipe for healthy soils.