Several years ago, I spent a summer working at a small garden in Chicago’s Woodlawn neighborhood. The work was sweaty and strenuous but also remarkably satisfying. My days were mostly occupied with transporting and turning compost, starting seedlings, mixing soil, watering, harvesting and drying herbs, and tending to vermicompost bins. One task that didn’t figure prominently into my daily routine, however, was weeding. Rather than spending hours uprooting every last foreign shoot from the beds and mulched paths, I took some advice from my supervisor, Martha, and let them take root. She taught me which varieties were edible and suggested ways to cook them. Lambs quarters, she warned, should be blanched first to remove any traces of toxic oxalic acid; amaranth leaves were better when young and tender. Armed with this knowledge, I returned home every week with armfuls of greens: peppery wild arugula and delicate lamb’s quarters were sautéed with garlic and plenty of olive oil before being incorporated into frittatas, blanched amaranths got tossed with spaghetti and salty cheese, and juicy purslane found its way into countless tomato and herb salads.