For the last couple of decades, a tiny insect called the Asian citrus psyllid has fed on the stems and leaves of the orange trees in Florida, infecting them with bacteria that cause a lethal disease called citrus greening. After years of seeking remedies—everything from antibiotics to GMOs to psyllid-sniffing dogs—with little success, Florida’s embattled citrus growers have discovered a new tool, thanks to the work of researchers at the University of Florida: planting cover crops amidst the orange groves.