Going into the store to buy some vegetables, I pause in front of the red cabbages, attracted by their gleaming deep red color. I notice they are separated into two sections, with different price tags. One is labelled certified organic, and it’s more expensive.

Taking an informal survey of the produce section reveals that most of the organic fruits and vegetables are more expensive than the conventionally grown produce, ranging from differences of ten to thirty cents in the case of carrots, green onions, tomatoes, and celery to an extreme difference involving Bartlett pears of over a dollar and a half. In most cases, organic and non-organic look pretty much the same. Yet I notice several people happily loading up on organic peaches and lettuce.

“Organic produce makes up more than half of our produce sales,” says Ken Allison, produce merchandiser for Puget Consumers’ Co-op, which runs several natural-food grocery stores in the Seattle area. “It’s a growing business for us, and other stores are carrying more and more organic produce, too.”

So what entitles a peach to a little yellow sticker proclaiming its organic status and a higher price?

“Organic produce is grown without synthetically produced fertilizers or pesticides or fungicides or herbicides,” says Allison. “It is a certifiable system that is meant to make a sustainable agriculture. Organic means there’s a published set of guidelines you as a consumer can consider. And you can follow a paper trail back to the person who grew the product. You can trace your tomato back to the grower. You don’t get that with conventional agriculture.”

Organic farmers are certified by the Washington State Department of Agriculture. To be certified as organic involves several steps. A grower must fill out an application that documents the history of the land and the growing practices that have been used there. The grower must also develop a farm management plan that documents the practices and soil amendments currently being used. An inspector from the Department of Agriculture inspects the site, interviews the grower, and writes a report. In addition, there’s a minimum annual fee of $150. If the grower is in compliance with organic guidelines for two years, a certificate is issued. A grower can therefore be certified organic in three years, and must renew the certification each year.

Miles McEvoy, organic program manager for the Washington State Department of Agriculture, succinctly explains the requirements. “No synthetic pesticides or fertilizers, and a soil-building program has to be in place. It’s not just the absence of certain materials. The grower must have other procedures and materials in place for soil fertility and pest management. We verify that people that are making organic claims are making true claims, so that consumers that are buying organic products are getting what they’re paying for.”

Part of what they’re paying for is quality. But a big part of it also has to do with sustainability. When you buy organic, you’re supporting a biologically based farming system that can sustain itself without adding to the burden of pollution on the environment.

“Many pesticides are very disruptive to biological systems,” says Anne Schwartz, president of Tilth Producers, a nonprofit cooperative for organic agricultural growers. “We believe that when there is a high level of biological activity going on, we are closer in balance with what plants and animals need to thrive. We try to enhance the biological systems, to minimize the negative impact. There’s a problem with synthetic pesticides and fertilizers because their by-products can be toxic to the whole web of biological systems that support life. Organics tend to be short in duration and to break down into products that natural processes can break down further. That’s not the case with synthetics. Food safety is an issue for us, but it’s more what we’re doing to the soil. Soil health is the foundation.”

Soil health increases with the level of organic matter in the soil. This quality is called tilth, and means that the ground can be easily worked and has increased nutrient availability and water retention. In contrast, land pumped up with chemical fertilizers can grow good crops but may not be as resistant to drought, pests, diseases, and erosion. The soil may become compacted, requiring heavier machinery to work.

Organic growers use natural methods to increase fertility and organic matter. They may grow a green manure crop that adds nutrients to the soil, and plow it right in. They may apply compost or animal manure. Karen Mallin, who runs a small organic vegetable-growing operation in West Seattle descriptively called the Backyard Greenhouse, uses Zoo Doo, steer manure, liquid fish fertilizer, greensand, bone meal, and kelp meal, among other things.

“I don’t use any chemicals at all,” she says. “I work on my soil. Every year, as my soil gets better, my garden gets better. I’m finding that the healthier my soil is, the healthier my plants are, and the fewer bugs they have.”

Schwartz owns and runs a diversified small farm in the upper Skagit Valley, growing raspberries, blueberries, potatoes, carrots, winter squash, and ornamental nursery crops. Her blueberries provide an excellent example of why organic produce costs more. Blueberries can be attacked by a fungus called mummy berry that prevents berries from developing. The berry remains on the bush, but turns gray and dry.

The organic control is to physically disturb the soil under the plants. A conventional grower might apply a fungicide spray. But an organic grower has to have people out there with rakes once a week over perhaps a five-week period, incurring labor costs which are more than the cost of fungicide.

“Production costs of organic produce tend to be higher,” says Allison. Another example is weed control. For large-scale weed control, an organic grower tills a field, waits three weeks for the weeds to sprout, tills them under, and then repeats the process. This provides good weed control, but the grower has six weeks of bills and the cost of tractor work with no money coming in. A conventional grower may already have a lettuce crop in that time.

The choice to buy organic produce is not solely adjudged on the issue of chemicals or no chemicals. And conversely, conventionally grown produce is not necessarily loaded with chemical residues that threaten human health.

“Organic produce is not completely free of chemicals,” says McEvoy. “Earth is a closed system. Using sophisticated enough equipment, you can detect low levels of chemical residue everywhere. In general, we don’t find many residues in organic products, and when we do, they’re at extremely low levels, barely detectable. Ninety-nine percent of conventional products have residues below EPA tolerance levels.”

However, many environmental groups are concerned about produce from foreign countries that may have been treated with pesticides banned in the United States, according to Schwartz. Some of these chemicals are actually produced here and shipped to other countries, only to return as residues in produce. Consumers who buy produce labelled certified organic have the reassurance of knowing where and how it was grown.