Historically, greenhouse vegetable production has been located in northern latitudes. In North America, most commercial producers are located in the northern United States and in Canada where growers raise lettuce, tomatoes, cucumbers, and other crops primarily for spring and summer markets.
Most of the greenhouses are located near their markets and emphasize production of very high quality, fresh produce. The cost of heating and low light levels combine to make spring production an expensive operation in northern latitudes where the winters are long and cold.
In contrast, Southern winters are mild and sunlight can be abundant, a fact that requires greenhouse operators, in the south, to ventilate for cooling as often as they heat. Because of its mild climate, production in southern greenhouses takes place primarily during the winter and spring.
North Carolina Greenhouse Vegetables Growers/Shipper List