Explore Campanula Medium: The Enchanting Canterbury Bells

The Canterbury Bells, scientifically known as Campanula medium, is an annual, biennial, or perennial herbaceous plant from the bellflower family.

Its bell-shaped flowers are usually blue, and it thrives in cool summers and mild winters, preferring environments with ample sunlight, although it can tolerate partial shade.

The plant bears a 3-5 chambered capsule fruit with persistent calyx lobes that split at the top or bottom, revealing numerous, smooth, and oval-shaped seeds.

There are over two hundred species of Canterbury Bells, most of which are native to the northern temperate zones, particularly in northern Europe and Asia, with a few in North America.

They are ideal for small gardens as flower beds or border materials. Combining Canterbury Bells and ornamental sunflowers with ivy, golden sands, and basket of Dianthus, can create a vibrant and thriving atmosphere.

If purple Canterbury Bells are used as the primary flower with white lilies, swallow herbs, and Asparagus fern, it creates a tranquil and elegant beauty.

I. Physical Features

Most Canterbury Bells are perennial herbs, some with long horizontal rhizomes, others with a short stem base and thick roots, and a few are annual herbs. The leaves are all alternate, with some basal leaves forming a rosette.

The flowers are either solitary and terminal or form umbrella-like inflorescences, sometimes grouped into conical or head-like inflorescences without peduncle or pedicel. The calyx and ovary are fused, with five lobes, sometimes with appendages between the lobes.

The corolla is bell-shaped, funnel-shaped, or tubular-bell-shaped, sometimes almost radial, with five lobes. The stamens are free, rarely with anthers sticking together to varying degrees.

The filaments are enlarged at the base to form a lamellar shape, and the anthers are long rod-shaped. The stigma is 3-5 lobed, with lobes curved back or spirally curled. There is no flower disc. The ovary is inferior, with 3-5 chambers.

The capsule fruit has 3-5 chambers, with persistent calyx lobes that split at the top or bottom. The seeds are numerous, oval-shaped, and smooth.

II. Growing Environment

Canterbury Bells prefer cool summers, mild winters, and plenty of sunlight, but can tolerate partial shade. They are sensitive to temperature, growing best at 13℃-18℃, germinating best at 20℃-22℃, and stopping growth with leaves turning yellow when the winter temperature drops below 2℃.

High temperatures above 28℃ in summer are unfavorable for plant growth, and temperatures between 30℃-35℃ cause leaf yellowing and falling, and even whole plant wilting.

In the Zhuhai region, Canterbury Bells are not suitable for summer and autumn planting, but winter and spring planting is more appropriate. Canterbury Bells like dry and drought-resistant conditions and dislike moist conditions.

Therefore, they do not grow well in excessive rain or poorly draining soil, leading to yellow leaves, elongated plants, extended internodes, and smaller flowers. This can be regulated by controlling watering.

Canterbury Bells are not strict about soil requirements, but they thrive best in loamy soil rich in organic matter and with good air permeability. The optimal pH for the substrate is between 5.5 and 6.2.

III. Growth and Propagation

The primary method of propagation for the Wind Chime Flower is through seeding. In the Guangdong region, it is best to sow the seeds in early autumn, typically from late July to early August of the lunar calendar.

By the time of the Spring Festival, the plants will be in bloom. It takes approximately six months from sowing to blooming, so the sowing time can be determined based on the desired blooming period.

As the seeds of Wind Chime Flower are quite small, it’s important to choose the right nursery bed before sowing. The nursery bed should be in a sunny location with high groundwater levels, good drainage, and sandy soil that is loose and fertile.

The soil should be thoroughly turned over and broken up at least twice, removing any stones and weeds. The main pests of the nursery bed include mole crickets, weevils and tiger beetles, which pose a significant threat to the soil and the seedlings.

Disinfecting the soil before sowing is thus necessary. Furthermore, the seeds should be soaked for 10-12 hours and dried before sowing.

They are then mixed with sand in a 1:5 ratio before being sown. The soil should be thoroughly watered before sowing, with the seeds evenly distributed over the bed.

After sowing, the soil should be kept slightly moist but not too wet, and the temperature should be maintained between 20-24°C. Germination typically occurs 14-16 days after sowing.

IV. Distribution Range

There are more than 200 species of Wind Chime Flowers, most of which are found in the Northern Hemisphere. The majority of these species are native to the northern part of the Eurasian continent, with a few in North America.

V. Disease and Pest Control

Rust disease primarily affects the leaves, stems, and buds of the Wind Chime Flower. Infected leaves exhibit yellow-green blister-like water spots that gradually expand. When these blisters rupture, they reveal a pile of reddish-brown summer spores.

The leaf tissue surrounding the disease spot turns pale yellow, and the symptoms on the stem and bud are similar to those on the leaf. Affected plants exhibit stunted growth, and in severe cases, the leaves become scorched.

Powdery mildew is a fungal disease that often affects the leaves but can also affect the branches, peduncles, buds, and young shoots.

The surface often displays a layer of white powdery mold, which turns gray in the later stages. Affected plants appear stunted, with twisted, deformed, and wilted young leaves.

Leaf spot disease initially appears as water-soaked necrotic spots on the leaves, which quickly turn deep brown. The disease spots have clear and dark concentric rings, with a yellow halo on the periphery.

VI. Main Value

Landscape Use: Wind Chime Flowers are suitable for small gardens as bedding and border materials. A vibrant and thriving atmosphere can be created by pairing Wind Chime Flowers with ornamental sunflowers, ivy, golden moss, and basket-planted Dianthus.

Flower Bed Performance: As an annual plant, Wind Chime Flower can overwinter in warm regions and can be used in flower beds, rock bamboo gardens, or along the borders or edges of gardens. Potted Wind Chime Flowers can be maintained in 15-20 cm pots in areas ranging from partial shade to full sunlight.