Balloon flower is for those of us that love the tall lavender blue Campanulas of spring and want to carry their rich hues and graceful wands of bloom throughout summer. This long-lived stalwart of cottage gardens has dusty blue buds that swell into a balloon and then open into deep-throated stars, closing late in the day to be replaced by a freshly blooming flower the next day. Deadheading is a must but not a chore; I can't resist the satisfying pop as the faded flowers separate from the stem. The glossy dark green leaves turn golden yellow in fall, adding another season of interest.