Blue Flag Iris

Blue flag iris is easier to place than most people assume. Iris versicolor will grow in an ordinary garden bed that stays reasonably moist, and it will also take a pond edge or several inches of standing water, so it covers a range of sites that few perennials handle. It reaches 24 to 36 inches tall and 18 to 24 inches wide in full sun to part sun, hardy from Zone 3 through Zone 8, and starts flowering by the second season. Violet-blue flowers open in late spring, marked with yellow and white at the throat, carried above the foliage on sturdy stems. Bees and hummingbirds come to them through the bloom. The foliage does as much work as the flowers. Stiff, upright, sword-shaped leaves in blue-green, holding their form all season and giving a border some vertical structure. Blue flag grows wild in marshes, wet meadows, and along shorelines. The root system knits soil together, which makes it useful for holding a shoreline or a rain garden edge, though it does not need either job to earn a spot. It spreads slowly by rhizome into a wider clump. Deer leave it alone.