Campanula carpatica Carpathian Harebell, Bellflower Size: 6" to 12" high by 12" wide. Hardiness: Zones 2 to 9. Heat Zones: 7 to 1. Habit: The triangular, toothed dark green leaves of Carpathian harebell make it a wonderful choice as an edging plant. Each plant forms a rounded mass of leaves often nearly covered with upturned, bell-shaped flowers up to 2 inches across. Culture: Full Sun to light shade.