This under-appreciated annual bears the most beautiful, satiny pink or white flowers for weeks in summer. It also goes by the charming name farewell-to-spring, perhaps because it blooms just as spring temperatures are rising. Plant it once and you won’t want to go a growing season without it. Native to areas of North America, this plant does best in areas with cool summers and in moist, well-drained soil. It’s a great cut flower, too. Although you can sometimes find it as established seedlings, most gardeners will need to start it from seed.