Campanula, more commonly known as bellflower, grows natively in temperate areas of North America. Gardeners value this perennial plant for its attractive, bell-shaped flowers that appear in late spring through summer in shades of white, pink, blue or purple. Cold hardy to zone 3, campanula thrives in most areas of the United States, reaching up to 6 feet in height with proper care. Perennial borders and rock gardens often feature bellflowers, but they thrive in any setting as long as they receive adequate light, moisture and nutrients for growth.
Plant campanula in a location that receives full sunlight throughout the day. Spread a 1-inch layer of aged manure over the planting site and use a garden tiller to amend the material into the soil before planting. Space campanula plants 9 to 12 inches apart.
Apply a 2-inch layer of mulch to the soil surrounding campanula after planting to hinder the growth of weeds and insulate the plant's roots. Keep the mulch 2 to 3 inches from the crown of the plant to provide air circulation and reduce the risk of rotting.
Water once each week during spring, summer and fall to keep the soil consistently moist. Reduce the frequency of watering to once every 10 days during winter, when the plant is dormant. Apply water twice per week during periods of extreme heat and drought.
Feed campanula once every six weeks using a balanced 10-10-10 NPK fertilizer. Water both before and after applying to reduce the risk of root burn or injury. Apply at the rate recommended by the manufacturer for proper dosage.
Remove spent campanula flowers as often as possible to encourage the production of new blossoms and to lengthen the blooming season. Pinch off the flowers at their point of origin, or the area where they meet the stem, to reduce damage.