Urban farming is usually thought of as a niche business for high-end food produce. In Chicago, it has taken on a new meaning. Police in a helicopter stumbled upon what may be the largest outdoor pot farm in the city’s history. Planted in rows and spread over an area the size of two football fields, as many as 1,500 plants averaging 6 feet tall were growing amidst heavy brush in an industrial area on the city’s South Side. “This would not be visible from the street,” said Chicago Police Superintendent Garry McCarthy at a press conference today. “It’s surrounded by...