With proper care the cut stems of Campanula will last in a vase for 20 days. Recut the stems every few days and refresh the vase water.
Exposure: Full sun
Sow indoors 8-10 weeks before planting out date. Just cover the seeds lightly with seed starting mix. Keep the soil moist at 10-15°C (65-70°F). Campanula seeds should germinate in 20-30 days.
Barely cover the tiny seeds. Use fresh seed starting mix and keep it moist until germination. Harden seedlings off over the course of at least one week. Transplant out after last frost at 25-30cm (10-12″) apart.
Choose any well-drained garden soil with a neutral pH range of 6.0-7.0. Trim plants lightly after flowering to encourage a second bloom. Approximately three weeks after sprouting, the plants should have 2-3 true leaves and should be ready for transplanting. Campanula produces a tap root that should not be confined in cells or small pots, so do not delay transplanting if possible. Space or transplant 20-30cm (10-12″) apart. Mulch around the plants in summer to help keep the roots cool.