Urban ag consists of "backyard, rooftop and balcony gardening, community gardening in vacant lots and parks, roadside urban fringe agriculture and livestock grazing in open space," according to USDA.

Atop Red Star Macalline Group’s headquarters sits a rooftop farm called Yiyun, which translates as “leaning on the clouds.” Chilies, white gourd, eggplant, chives, and other vegetables flourish across the 4,600-square-meter garden cultivated by the company, which is China’s largest national furniture retailer. The harvested produce is used in the staff cafeteria, and the farm also provides thermal insulation for the building’s top floor, which houses expensive rosewood furniture.

To sustain the hop farm, Gerhold set up a C.S.A., a community-supported agriculture operation, for additional revenue.

Brooklyn Grange’s roots date to 2009, when Ben Flanner, now president, quit his job in finance to open Eagle Street Rooftop Farm in Brooklyn. One year later, joined by Schantz and other partners, he opened the organization’s permanent foothold in Long Island City; they soon after added the location in the Brooklyn Navy Yard. The organization has since become a worldwide leader in urban agriculture efforts.