Harebell (Campanula rotundifolia) has beautiful and delicate purple bell-like flowers that bloom in clusters on and off from summer to fall. It is a short sized but fast growing perennial that usually produces flowers within its first year of growth. Rock gardens are an ideal location for this plant, or other sandy and well-drained locations in full sun or with some shade. To encourage more blooms, regularly remove dead flower heads. This species attracts hummingbirds!