Campanula rotundifolia (harebell) is a delicate-looking but surprisingly tough perennial that brings airy color to rock gardens, meadow plantings, and naturalized edges. You will see wiry, upright stems topped with small, nodding, bell-shaped blue flowers that bloom through summer, often with repeat flushes as conditions allow.
Give it full sun to part shade. In hotter climates, some afternoon shade can help it look its best. Plant it in well-drained soil and keep moisture moderate and even, especially while it is getting established. Once settled, it handles leaner, rockier ground well, which makes it a good fit for crevices, slopes, and thin soils.
At maturity, it typically stands about 12-18 inches tall and forms a modest footprint, spreading around 6-12 inches. Basal leaves may fade as flowering stems rise, which is normal for this species. Deadheading spent blooms can encourage additional flowering and keep the plant looking tidy.
Harebell is useful where you want a light, natural look: tuck it between stones, along paths, or among low grasses and other small perennials. It can be short-lived in some gardens, but it often persists by self-seeding when it is happy. Deer tend to leave it alone, and the flowers are a welcome nectar source for pollinators.