By Marty Ross
Our plants have one great advantage: Midwestern soil is terrific. But there are lots of things we can do to make the soil in our gardens even better—and that’s what I do in my own backyard. There's nothing much to it: I improve the soil in my garden one shovelful at a time.
Native prairie grasses, with their deep root systems, built up Midwestern soils. When settlers broke up the prairie sod and planted grains, the region became the breadbasket of America. Our soils are full of organic matter, and are dark and fertile. But generations of use and development have changed our soils, and not for the better.
As every gardener knows, the soil in your garden may be quite different from the soil in a friend’s garden across town. In fact one neighborhood can have many kinds of soil.
You don’t need a soil test to find out what kind of soil you have; you need a shovel test, says Ben Sharda, director of Kansas City Community Gardens. Take a shovel and dig a hole. Look for a dark color and loose texture in the soil. That’s the rich loam topsoil that everyone loves.
Then check the drainage. Pour a watering can full of water into the hole and see what happens. It's best if the water drains through fairly quickly. “You don’t want a soupy bottom,” Sharda says.
In my own backyard in Kansas City, the soil is rather heavy clay. Clay soil teems with minerals, supports extensive root systems, and holds plants firmly up. It retains moisture well—sometimes too well. I add compost to improve drainage, make it easier to work, and complement with nutrients and micronutrients. Compost improves all soil, lightening clay soil and adding organic matter to sandy soil.
Compost—from a bag or from your own backyard compost heap—helps improve moisture retention and also makes heavy soil drain better. Beneficial bacteria and microbes thrive in compost, and in healthy soil full of organic matter. So do earthworms. They’re “the most recognizable of all animals in the soil food web,” says Jeff Lowenfels, author of Teeming with Microbes, “and, as it turns out, one of the most important to gardening.”
Whenever I plant I keep a bucket or a wheelbarrow full of compost nearby so I can add a shovelful to the soil in each hole. Then I mulch around the new plants with compost.
Mulching is another great way to improve any soil. A layer of organic mulch—such as autumn leaves, compost, or mulch from a bag—helps preserve moisture, limit weeds, and, as the mulch breaks down, improves the quality of your soil.
Healthy soil supports healthy plants. Improving the soil in your garden helps plants grow vigorously. Healthy plants resist bugs and blights, and stand up better to extreme weather.
“We live in an area that has the best soil on earth,” says Alan Branhagen, horticulture director of Powell Gardens, the botanic gardens just east of Kansas City in Kingsville, Missouri. But even the best garden soil can do with a little help to keep it that way.