I’m just back from Detroit. Since the 1960s, the population there has declined from 1.8 million to about 650,000. Now nearly a third of this once thriving city is vacant. Countless houses have been demolished, while others have been transformed into art objects and still others left to rot. Services , including grocery stores, are few. But some imaginative and energetic people are hard at work raising vegetables on vacant lots. Below are a few early picks from my time in Detroit.