Canterbury bells (Campanula rotundifolia) are a biennial plant popular in European and North American landscapes. It is a medium-sized specimen with an upright form featuring numerous vibrant, sweet-smelling bell-shaped flowers that range from white to violet. Indigenous to the Mediterranean climate of southern Europe, Canterbury bells do poorly in humid environments, such as the southeastern United States, but perform well in the northern United States. Canterbury bells grow quickly, bloom for two years, and then die. You should begin the planting process indoors in the winter and then transfer to the outdoors in the spring.
|Common Name||Canterbury bells, cups and saucers|
|Botanical Name||Campanula medium|
|Plant Type||Annual, biennial|
|Mature Size||20-26 in. tall, 12-18 in. wide|
|Sun Exposure||Full, partial|
|Soil Type||Moist but well-drained, loamy, sandy|
|Soil pH||Neutral, acidic, alkaline|
|Flower Color||Pink, white, purple, blue|
|Hardiness Zones||5-8 (USDA)|
Canterbury Bells Care
Canterbury bells are easy to plant and care for. They grow best in full sunlight in moist soil, and cool climates and nutrient-rich fertilizer will ensure a healthy bloom. As a biennial, Canterbury bells take two years to bloom, after which they will die, so many gardeners choose to plant new seeds yearly. Usually, Canterbury bells are grown in flower beds, which are best suited for the second row in a bed of three rows, staggered according to height.
While infestations and disease aren't common, the plant can be affected by various insects and fungal diseases, both of which are treatable when addressed early. You should overwinter Canterbury bells indoors during their first winter to prepare them for later frosts.
Canterbury bells flower best when exposed to four to six hours of full sun daily. They can grow in partial sun, but full sun is ideal.
Canterbury bells require well-drained but moist soil. The soil should be loamy or sandy, and a wide range of pH levels is acceptable, from neutral to alkaline. Still, near-neutral is ideal.
You should water your Canterbury bells regularly during the growing season, but be sure not to overwater. They will die in drought or flood, so maintaining good moisture retention is essential.
Temperature and Humidity
Canterbury bells do best in cool climates. If you live in an especially hot area, provide your plant shade. Cool summer weather is ideal for Canterbury bells, and temperatures over 80°F can harm your plant's health.
Fertilize your Canterbury bells in spring with a nutrient-balanced fertilizer. Low nitrogen 5-10-5 NPK fertilizer is recommended. Hose the soil after fertilizing, so the fertilizer reaches the plant's roots. You can mix compost into the ground to increase fertility and improve soil drainage.
Types of Canterbury Bells
- Campanula medium var. calycanthema alba: 24 to 36 inches tall; white flowers
- Campanula medium Bells of Holland: 18 inches tall; pink, purple, or white flowers
- Campanula medium Champion Pink: 2 feet tall; pink flowers
- Campanula medium Dwarf Bella Mix: 14 inches tall; blue, lilac, pink, or white flowers
- Campanula medium Double Melton Mix: 3 feet tall; flowers dark pink, light pink, or purple; double blooms
To prune Canterbury bells, remove dead foliage as soon as possible, and cut or pinch flowers as they fade. If you notice your plant becoming too large, you can prune excess flowers, even if they appear healthy. You should lightly prune Canterbury bells throughout the summer.
How to Grow Canterbury Bells From Seeds
- Sow the seeds in a tray filled with potting soil in late winter
- Sprinkle a light layer of vermiculite over the seeds.
- Using a spray bottle of water, mist the vermiculite to keep it evenly moist but not soggy
- Maintain a temperature of 65˚ to 70˚ F.
- When the seedlings emerge three to four weeks later, place the tray on a sunny windowsill and keep the soil evenly moist
- In mid-spring, begin hardening off the seedlings.
- Transplant the seedlings into your garden once frost has passed
Potting and Repotting
You can plant Canterbury bells in regular potting soil without taking many additional measures. However, you may add some sand to the mixture. Choose a pot, tub, or container with drainage holes to ensure the plant doesn't become overly wet. Repotting is best done in early spring, and given the height of the plant, staking is helpful for extra support.
It's best to grow Canterbury bells indoors for their first year to be well-prepared for winter. You can do so by using a thick layer of mulch and planting in the spring. Water very lightly during frosts.
Common Pests & Plant Diseases
Common pests and diseases affecting Canterbury bells include aphids, mites, slugs, and snails. The plant can also develop root rot, powdery mildew, and rust. Fungal diseases, such as rust, become visible as lesions on the leaves and then as open pustules that can spread to surrounding flowers. Pruning and good air circulation can help protect your Canterbury bells from disease.
How to Get Canterbury Bells to Bloom
Canterbury bells bloom bell-shaped, pink, blue, white, or purple flowers in the early spring through midsummer. They produce a sweet fragrance, sometimes thought to smell minty. Deadheading the flowers promotes growth throughout bloom. Attentive care and proper watering practices will help Canterbury bells bloom fully.
Common Problems With Canterbury Bells
While Canterbury bells are relatively easy to grow and aren't particularly susceptible to pests, they can still suffer from issues common to all bellflowers. Owners should pay attention to discoloration and overcrowded flowers.
Fungal diseases will cause the leaves of your Canterbury bells to become yellow or brown and are difficult to manage once the spread begins. This can help be prevented by avoiding overwatering.
Canterbury bells produce a large volume of flower spikes, weighing down the stem and causing the plant to collapse. You can help prevent this by staking your plant and pruning as you notice excess growth.
How long do Canterbury bells live?
Canterbury bells live for two years.
What plants are similar to Canterbury bells?
The Campanula genus boasts a wide array of bellflowers similar to Canterbury bells. Carpathian bellflowers, for example, resemble Canterbury bells and require nearly identical care but are perennials.
Can you grow Canterbury bells indoors?
You can grow Canterbury bells indoors, but it's best to limit this to initial growth, as the flowers thrive outdoors.