Campanula, or bellflower, come in varieties suited for most climates. A mid-summer bloomer, the flowers stay on the plant into fall until the first frost, adding color to your late summer garden. Each flower stalk produces many purplish-blue flowers. The flared bell-shaped flowers prefer partial shade to full sun so plant them in areas under trees with dappled sunlight or brightly lit rock gardens. Start bellflowers directly in the garden after the soil warms but before the last frost of the season.
Prepare a well drained bed for planting. Work compost or other organic material into the soil to build the bed up 3 inches and improve drainage.
Sow seeds on the soil surface 12 inches apart. Cover with 1/8 inch of soil.
Water until the soil is just moist after planting. Water only during one to two times weekly when there is no rainfall or natural moisture thereafter.
Fertilize with a general purpose fertilizer once in mid-summer. Fertilize the second spring after the new shoots appear in addition to mid-season fertilization.
Pinch off the spent blooms to encourage further flower and foliage production. Pinch off the faded flower right above the nearest leaf or bud.
Allow the foliage to die back naturally. Cut down the old leaves if desired after the first frost kills off existing foliage.