You don’t need acres of luscious, green fields in order to grow food. You don’t even need soil or sunlight to do it either. In crowded cities, urban farmers are getting innovative and growing food in the unlikeliest of places, from bomb shelters to abandoned industrial yards using hydroponic systems. These systems can’t replace the enjoyment that comes with growing food in soil, but they can save water and produce safe food, either indoors or outdoors, in a world with increasingly scarce resources.