Campanula plants come in many varieties. They grow from 4- to 6-feet tall and come in many shades of pink, red, blue and purple. All varieties of campanula have hanging, bell-shaped flowers, although the size of the flower varies with the height of the plant.
Most campanulas bloom in June and July, so it is best to plant seeds or seedlings in May, though they can be sowed in August and protected during the winter. Campanulas are biennials, meaning they bloom every other year, so plant some each year to ensure flowering plants every summer.
In general, campanulas like cool weather, but will grow in warm regions. They grow best in full sun and thrive in soil enriched with bonemeal. You can grow campanulas directly from seed, but seedlings show more immediate results.
Choose an area to plant the seedlings. The area must have full sunlight and low foot-traffic.
Break up the soil by pushing the claws of the hand tiller into the soil and twisting it sharply. Continue until all the soil in the area is loose and workable.
Spread bonemeal evenly over the planting area. Bonemeal is ground animal bones, sometimes mixed with potting soil and is very high in nutrients. Mix it into the soil with short, smooth strokes of the rake.
Dig a hole with the trowel about six inches deep. Take a seedling from the tray and loosen the root ball with your fingers. Put the seedling in the hole and cover the roots with soil. Water generously.
Repeat step 4 for all of the seedlings, leaving a square foot of soil around each plant. This will give the roots room to spread out.
Water campanula plants each day in dry weather and occasionally spread more bonemeal or other organic fertiliser around the base of each plant. Remove dead blooms from the plants to lengthen the blooming season.
Pack handfuls of fallen leaves around each campanula plant in the fall. This will keep snow from crushing the leaves and causing decay.
Stake campanulas before they get too tall and adjust the stakes as the plants grow.