Campanula, more commonly known as bellflower or canterbury bell, includes biennial, perennial and annual flowering plants that grow natively throughout the Northern Hemisphere. Valued for its attractive, bluish-purple bell-shaped flowers, campanula reaches up to 30 inches in height with a spread of at least 3 feet. Rock gardens, woodland gardens and flower borders often feature bellflower, which tolerates a variety of growing conditions. Hardy to zone 3, campanula plants thrive in most of the United States with only minimal care.
Plant campanula during early spring after the threat of frost has passed. Choose a planting location that consists of well-drained, fertile soil that receives at least six to eight hours of full sun each day. Space campanula plants 12 to 18 inches apart.
Spread a light 1-inch layer of organic mulch over the soil surrounding campanula plants to provide insulation and suppress the growth of weeds. Allow about 3 inches between the base of the plant and the mulch to provide enough air circulation.
Water once each week during spring, summer and fall to prevent the soil from completely drying out. Increase watering frequency to twice per week during periods of drought. Do not water during winter, when the plant is in a state of dormancy.
Feed campanula plants once every two months during spring, summer and fall. Use an all-purpose 10-10-10 NPK fertilizer to provide proper nutrition. Follow the directions on the package for proper dosage and application instructions.
Remove faded and dead campanula flowers as often as possible to encourage the formation of additional blossoms and prolong the blooming season. Do not allow any flowers to turn into seed heads, as this will cause blooming to end shortly after.