Farmers are making inroads supplying local food to hungry city foodies, but many producers are trying to grow more food in urban centers. City real estate is at a premium, so some producers are finding more space by using what’s called “vertical farming,” and going up rather than spreading out....

Farmers are making inroads supplying local food to hungry city foodies, but many producers are trying to grow more food in urban centers. City real estate is at a premium, so some producers are finding more space by using what’s called “vertical farming,” and going up rather than spreading out....