One might expect to drive out into the country to buy the freshest fruits and vegetables at a roadside stand.

But in Bob Pierson’s world, the best places to find local produce are at farmers’ markets in densely populated urban areas—like the northwest corner of Philadelphia City Hall. It’s best, he says, because local farmers—half of them grow crops in the urban setting—bring absolutely fresh, high-quality goods to a location where throngs of very appreciative consumers can’t wait to get their hands on the merchandise. (continued)