Farmers' markets are where producers sell fresh, locally grown produce, or food made with local ingredients, direct to the public. As with organic farming, there is no single, fixed definition but producers should be local (within about 25-30 miles of the market) and selling their own produce - i.e. they are the farmer, family member or direct employee. A large fraction of the produce - particularly during the winter - is grown in artificially-heated greenhouses.