You can find an organic option for almost anything these days -- food, shampoo, fabric, even toys. With so many different companies using -- and abusing -- the word, it can be difficult to figure out just what organic means.
Organic matters
Gardeners often talk about improving their soil. The best way to do that is not by fertilizing plants but by adding natural materials.
By JEFF GILLMAN, Contributing Writer
April 27, 2010 at 9:19PM
But if you're a gardener, organic isn't a gimmick: It's the heart of the soil from which your garden grows.
A little history
When chemists use the word "organic," they're referring to a chemical that contains carbon. In the early 1900s, an English researcher named Albert Howard began to use the term to refer to a system of agriculture in which chemicals containing carbon from natural sources -- such as manure and dead plants -- were turned into the soil to make it better able to grow healthy plants.
Later, J.I. Rodale, one of the most famous organic activists, latched onto the term and popularized it through his magazine, Organic Gardening, as well as a number of books such as "The Organic Front." Published in 1948, this not-so-lighthearted treatise on the evils of industrial farming focused on how synthetic fertilizers were damaging our soil.
Since Howard and Rodale's time, many different meanings have been assigned to the word organic. But for gardeners, the most important meaning is the one intended by these pioneers: Get carbon into your soil.
A little science
Many chemicals contain carbon, from carbon dioxide to pesticides and medicines. We gardeners are mostly concerned with sugars and other carbohydrates that are formed when plant material is broken down by microscopic creatures in the soil. This broken-down dead stuff, which gardeners call "organic matter," is a necessary constituent of healthy soil.
When grass clippings, a banana peel, a dead mouse or any other plant or animal dies and starts to rot, it begins to be degraded by bacteria and fungi. As it breaks down, it does two things to help the garden. First, it releases nutrients, such as nitrogen and phosphorus, into the soil. Plants then take up these nutrients through their roots.
Second, the carbon-containing organic compounds become incorporated into the soil, where they do lots of things that benefit your plants. They hold water and nutrients like a sponge, until a plant can use them. Organic matter also allows air into the soil so that the plant's roots can breathe. (Although we don't often think about it, plants need to breathe just as we do.)
Into the soil
There are two easy ways to deliver organic matter to your soil. One is to add compost.
If you till compost (from your back-yard bin or from a garden center) into your soil, it immediately increases the amount of organic material. If you prefer not to till, adding compost on top of the soil will allow organic matter to slowly work its way into the ground over a number of years. Whether you till or not, you'll need to add a 2- to 3-inch layer of compost every year.
Mulch made out of natural materials, such as untreated wood chips or straw, keeps the weeds around your vegetables, flowers and shrubs at bay. But over time it also breaks down into organic matter and helps build the soil. Over the years, natural mulches have gotten bad press for stealing nitrogen from plants. In reality, that rarely happens unless the mulch was mixed into the soil around very shallow-rooted annuals. Even then, it doesn't cause serious harm to plants.
By using organic material, you can ensure that your soil stays healthy and capable of supporting the plants you want to grow for years to come.
Jeff Gillman is an associate professor of horticulture at the University of Minnesota. He's also the author of three books, "How Trees Die," "The Truth About Garden Remedies" and "The Truth About Organic Gardening" (Timber Press, $12.95).
