In this guest post, Fern Marshall Bradley, coeditor of Reader's Digest's All-New Illustrated Guide to Gardening, talks about a great technique for reviving sad garden soil.

 In the past two years, thousands of Americans have started growing fruits and vegetables in backyard and community gardens in a quest to provide fresh, nutritious food for themselves and their families. If you're one of those new gardeners, I hope you've had great success and discovered a fabulous variety of delicious tastes and healthful food. But if your garden hasn't been as productive as you'd like, perhaps you need to revitalize your soil by growing a cover crop.

What is a cover crop? It's a planting specifically intended to densely cover the soil surface and to add organic matter to the soil. The thick cover prevents erosion and keeps down weeds. And after the crop has grown for several weeks (or even a whole growing season), you'll cut it down and dig it into the topsoil. All that fresh green material provides a rich feast for earthworms and soil microorganisms that convert organic matter into nutrients that plant roots can absorb. The cover crop roots open up channels for air and water in the soil too. Cover-cropping is an all-around recovery program for sad soil!

 Two easy cover crops for home gardeners to manage are oats and buckwheat. You can buy the seed at some garden centers or from your favorite garden seed supplier (Johnny's Selected Seeds is one of my favorites). Here's how to plant a cover crop:

1. Clear away weeds and plant debris and loosen the top inch or two of soil.
2. Rake the soil surface smooth.
3. Watch the weather forecast, and when rain is predicted, sow the cover crop (for buckwheat, 3 to 5 ounces of seed per 100 square feet of garden; for oats, 5 to 6 1/2 ounces per 100 square feet). Scatter the seed by hand in sweeping arcs over the surface of the bed-oats and buckwheat are large seeds that are easy to sow this way.
4. Rake the soil again to cover the seed lightly. Firm the seeds into place by gently walking over the bed surface or tamping the soil surface with the back of a hoe.
5. Wait several days-you should see the crop sprouting! If rain doesn't materialize, you can set up a sprinkler to gently water the bed instead.
6. Let the crop grow for several weeks. If you notice weeds in the bed, you can pull them out, but the crop should quickly blanket the soil. (Note: once buckwheat starts to flower, it's time to end the crop.)
7. To finish out the process of cover cropping, you can use a tiller to turn under the crop, but I prefer a different method. I use my lawn mower or string trimmer to cut down the topgrowth, and I leave it in place to dry for a few days. I sometimes use the dried topgrowth as mulch in other parts of my garden, or I dig it right into the bed along with the roots and stubble.