Balloon Flowers (Platycodon grandiflorus), also known as Chinese Bellflowers, are handsome summer perennials that come to us from East Asia. They get their names from their puffy, balloon-like buds, which open out into bell-shaped flowers. At home in both northern and southern yards, they are easy to grow and have few problems. Balloon flowers have a reputation for blooming reliably year after year--for years or more in outstanding cases.
Size: Typically, balloon flower plants grow from 2 to 3 feet tall. Dwarf versions are only 6 inches tall. At maturity balloon flower plants spread from 10 to 18 inches wide. These plants do not spread vigorously over the years as many perennials do, because their fleshy roots grow deeply. For this reason they are tricky to transplant.
Foliage: Balloon flower leaves are 1 to 3 inches long, narrowly oval, with toothed edges. They're a shiny blue-green or gray-green and have a strong, leathery texture. They grow alternately along plant stems and turn pale yellow in the fall.
Flowers: Balloon flowers bloom for a month or more in early to mid-summer, sometimes longer. Their inflated buds expand into wide bell-shaped flowers having 5 petals with pointed tips. Each flower is 2 to 3 inches across, with a white star-shaped pistil in the center. They emerge individually at the tips of small branching stems that grow from the main stem. The flowers are usually a deep, rich blue-violet, but white, pale blue, lilac or pink flowers are available. Flower color is strongest along the veins of the petals, which gives them a pleasing textured or streaked effect. The flowers have no scent. Some gardeners swear the flowers glow at dusk; see for yourself.