This has been an ongoing, fun argument for years, amongst various friends of mine.
NYC's greenmarket program has rules. Like these:
Quote
REGION 1. The Region is defined by a circle, extending 120 miles to the south, 170 miles east and west, and 250 miles north of New York City. (See map in Appendix B.) 2. Producers from outside the Region are not eligible. The restriction to the Region does not apply to Producers who attended Greenmarket prior to 1998 and who have continuously attended each year since and including the 2005-06 market year. 3. Ocean Fishers must dock within the Region and catch fish from Mid-Atlantic waters. (Mid-Atlantic as defined by the Magnuson-Stevens Act of 1976.)
LAND and PLACES of PRODUCTION 1. Land. a) All land used for production must be within the Region. b) Producers must own or lease land they use for production. c) Producers that choose to lease land are encouraged to secure written long-term lease agreements, written with provisions that are beneficial to the Producer, and that provide protection for the Producer’s improvements.
So anything bought at the greenmarkets here is, in essence, "local." Don't look for oranges, lemons, limes (sorry, @JoNorvelleWalker), pineapples, etc. They're not available. Nor is salmon from Alaska (or anywhere, for that matter - I've certainly never seen salmon).
Does that mean everything is in season? Of course not; the growing season here is not as long as California's (which, for some vegetables, in some locations, is year round).
So I know that the potato or onion or apple I buy at the greenmarket in January wasn't harvested yesterday; it came from storage. I also know it didn't come from California.
Farm stands (which I believe @gfweb is referring to in the preceding post) are totally different animals. I used to stop at a farm stand on my weekly drives to DC, on the DelMarva peninsula. In summer, from their fields, great corn, tomatoes, etc. But they were also selling, you guessed it, lemons and limes and bananas and...
As with most consumer purchases, caveat emptor.