California is taking the lead in certifying where food is grown, but organizers of the effort said the issue is prevalent throughout the country. It may be even more common in cold-weather spots without California's long growing seasons, they said.

The number of farmers markets in the country increased by 16 percent in the last year, according to data released by the USDA. The current USDA Farmers Market Directory lists more than 6,100 farmers markets.

Please see the following L.A. Times article for more.