I'll make this short. I wish you could believe everything the folks at the market tell you, but you just can't. Unfortunately, we live in a world where too many folks are willing to exploit you and me. My last couple farmers market tips have been all about how to make your farmers market experience more meaningful in light of possible exploitation.
That brings me to Farmers Market Tip #3: Know The Rules. Hopefully the market you frequent has a set of policies for determining who can sell at the market and what they can sell. You should know these policies! If the market requires that the vendors at the market produce all of that which they sell, then you will know that you are not purchasing from "farmer pretenders". If your market requires all of its farmers to farm within 100 miles of the market, you will know you are purchasing local (or at least regional).
I would also like to encourage you to ask about and put some stock in third-party labels. Is the farmer at the market certified organic or carrying other state or national eco label? Whether you like these labels or not, they can assist you by doing some of the research on these farmers for you. Don't use labels alone, but they are yet another way to know what "rules" your farmer operates under.
While it is illegal to advertise yourself as organic without having certified, it does happen all of the time. Ask to see evidence of certification! Once you have established that the farmer you are getting to know at the market carries a third-party certification, get to know the rules behind that certification. USDA organic is one of many certifications out there and I have already produced a short description of what it means, but there are others out there.
The point is you should know the rules governing who is selling at the market and how they are farming. It is just one more way you can be sure you are doing the right thing. Hopefully you're out there supporting small-scale, local, sustainable farmers and not businesses anxious to exploit your desire to do so. You just have to do a bit of homework!
Vincent M. Smith