The poppies are in bloom in what I call my sun garden. Though it’s actually more a haphazard collection of flora, thrown together on a stretch of land that’s half hill and part swamp. It’s a cutthroat kind of neighborhood for plants, and only the intrepid survive. But those that do — monkhead, monarda, shasta daises, blue lobelia, goose-neck loosestrife — tend to thrive. Like most toughs, they’re...