Grow the campanula bellflower by planting it in moist, light soil with access to full sunlight. The bellflower needs to be watered regularly and fertilized twice a year.
Place a campanula bellflower plant in a location with well-drained soil and access to full sunlight throughout the day away from buildings, fences and any other structures that cast shadows. Immediately after planting, lay 3 inches of pine needles or straw mulch around the plant to keep the soil moist and cool. To prevent the soil from drying out, water the plants regularly directly at soil level. Avoid splashing the foliage as this can attract pests.
Twice a year, in the spring and summer, feed the plant a 5-10-10 fertilizer. Regularly snip off any faded flowers. Keep an eye out for any pest or fungal infestations. Mildew, which appears as a white powdery substance on the leaves, is a sign of a fungal infection. Amend the soil to improve drainage, or thin out the plants to increase air circulation. Prune any yellowed, wilted or diseased foliage immediately. Horticultural oil can be applied to the plant to control infestations but should be handled with care and avoided in temperatures above 90 degrees Fahrenheit.