Is produce from a home garden safer than store bought? 'It depends'

Many consumers responded to this summer's record foodborne illness numbers by buying more produce from farmers markets or growing their own at home. A third of Americans — 44 million households — grow some type of fruits or vegetables, up about 4% every year for the past five years, according to the National Gardening Association. But is buying from small farms or growing your own safer?

"As with anything, it depends," says James Rogers, director of food safety for Consumer Reports, which regularly tests retail produce. What shapes safety is the farming practices, and has less to do with the operation's size, he says. On one hand, large operations are regulated by cleanliness standards, and can track produce using bar codes, which can help to quickly trace back contamination.

But co-mingling huge volumes of produce in washing and processing warehouses can also lead to big outbreaks "You can have a problem if you have one batch that's contaminated, it will contaminate the entire batch," Rogers says. Most small growers, he notes, are exempt from Food and Drug Administration rules, dealing with irrigation or testing for microorganisms. So their practices vary widely, which is how you end up with contrasting food-safety approaches like those of Phil Tocco and Dave Whitinger — both veteran gardeners growing lettuce in their own home gardens.

Tocco, who lives in Jackson, Mich., is a Michigan State University agricultural food-safety expert who advises farms of all sizes. He considers himself more fastidious than your average farmer: "Some backyard gardeners don't understand the risks – the fecal risks." Tocco's wife contracted amoebic dysentery — a painful intestinal parasite — from lettuce grown at a small farm 25 years ago. He says she still suffers from aftereffects of the infection.

So Tocco keeps his garden free of animals and small children, who might track feces and pathogens like salmonella, E.coli, or Cyclospora that may be in it. He won't, as some gardeners do, use water from barrels collecting rainwater in his garden, because they might harbor bacteria. Want the latest stories on the science of healthy living?

Subscribe to NPR's Health newsletter. "If then someone uses water from that rain barrel that's going to go into their mouth in a day, it's kind of like bacterial soup," he says. Tocco replicates what he can of the sanitary practices he preaches: He harvests with sanitized hands and buckets, won't harvest food near bird or other wild animal droppings, and uses a commercial form of hydroxyacetic acid to rid any pathogens on his leafy greens.