Geraniums, those pom-pom-blossomed stalwarts of window boxes and patio pots, epitomize summer cheer. But that’s no reason to condemn them to the compost heap come fall. Though primarily sold as annuals in the U.S., the joyful plants mostly hail from South Africa and are what pros call “tender perennials.” Insufficiently hardy to survive the freezing outdoors, such plants can last (and even thrive) if treated to more hospitable conditions, a practice known as overwintering. The technique: Stash a few specimens on a sunny sill when temperatures dip, and your minimal care will beget bright blooms and fragrant foliage through the bleakest winter.
You’ll also be in good company. Cultivated in Europe since the 1600s and embraced by some prominent early Americans (Thomas Jefferson cluttered the White House’s windows with them), geraniums became emblematic of English country-house style in the 19th and 20th centuries. More recently, buzzy designers who have mastered the genteel-boho look, such as Ben Pentreath and John Derian, have found geraniums germane to their Instagram feeds. Every September, James Coviello, a designer in New York’s Hudson Valley, places red garden geraniums in kitchen windows, bedrooms and bathrooms—anywhere that needs a lift. “They really have this storybook, ‘Where the Wild Things Are’ look,” he said.