Building Great Soil
By: Warren Schultz
To paraphrase a famous campaign slogan: "It's the soil, stupid." Meaning, of course, that--no matter what varieties you plant, or how you stake, feed, water, and pamper them--it's all for naught if your soil is not in good condition. (And, even if your soil seems to be in prime condition, it can always stand improving from year to year.)
Know Your Soil
Fortunately, it's not too late to tend to the soil wherever you garden. We talked to several soil experts around the country, and though they all have their own preferred methods of soil improvement, they agree on one thing: start with a soil test. Otherwise you're flying blind. As John Dromgoole tells his customers, at Garden-Ville nursery in Austin, Texas, "If you want me to help you, I need a road map."
Not all soil tests are the same, however. Dromgoole recommends using a service that provides recommendations in terms of organic fertilizers. A complete test should also reveal the organic matter content of your soil. It's usually less than it should be. "Most of the soil tests that we do, we find about a 1 percent level of organic matter," says Denny Schrock, home horticulture specialist at the University of Illinois. "We'd like to see something closer to 5 percent, but if we get 3 percent, we're pretty happy."
Even more important than knowing the fertility of your soil is knowing its texture--whether it's sand, silt, clay, or something else--says Richard Merrill, director of the horticulture department at Cabrillo Community College in Aptos, California. Testing the texture is something that every gardener can do at home.
To get a general idea of your soil texture, you can perform the ribbon test. Take a handful of moist soil and roll it between your palms until it forms a ribbon. If it feels gritty and breaks apart immediately, the soil is predominately sand. If the soil feels smooth, and holds its shape for a short time before breaking apart, it's mostly silt. However, if it feels sticky and holds together in a ribbon, then it's clay.
Even without knowing the soil's exact texture, it's a safe bet that adding organic matter will help. The only question is how you're going to do it.