Balloon flowers (Platycodon grandiflorus) are clump-forming perennials in the bellflower family (Campanula).    They are hardy in Zones 3-8 and prefer full sun to part shade.   As the plant grows, the buds swell like small balloons before emerging as upward-facing star-shaped flowers with 5 petals. 

Balloon flowers usually grow about 0.5 m.   The leaves are lanceolate and green with a blueish shade.    They bloom in summer with multiple flowers from each stem.     

We can propagate them from seed or buy them in a nursery. Once established, they are harder to move because of a long taproot.   They are low-maintenance, reliable, and long-lived, a valuable addition to a home garden.