One day in 2005, just before Hurricane Katrina blew through Florida and devastated New Orleans, Susan Halbert stood before a pomelo tree on a farm outside Miami. Something about this tree did not look right. It seemed undernourished: its leaves were sparse, and its melon-size citrus fruit was lopsided. Yet all the other plants in the garden were thriving, and the woman who took care of them had carefully tended the pomelo with a fresh layer of fertilizer. “She clearly knew how to grow plants,” says Halbert, an entomologist for the Florida Department of Agriculture and Consumer Services (FDACS).