Canterbury Bells (Campanula medium) are classic garden flowers, cherished for their distinctive bell-shaped blooms. These elegant biennials bring a charming, old-fashioned appeal to cottage gardens and are often cultivated for cut flowers. This guide provides detailed instructions for growing them successfully from seed.
Preparing for Seed Starting
Starting Canterbury Bells from seed requires specific materials. Gather seed starting trays or small pots. A sterile seed starting mix is important, offering excellent drainage and aeration while being free of pathogens and weed seeds. Use a gentle spray bottle for watering to avoid dislodging tiny seeds or delicate seedlings.
Select high-quality, fresh Canterbury Bells seeds from a reputable supplier. Before sowing, thoroughly moisten your seed starting mix until it is evenly damp but not waterlogged; this ensures uniform hydration around the seeds. While not strictly required for fresh seeds, cold stratification can enhance germination rates by mimicking natural winter conditions. This involves placing seeds in a damp paper towel inside a sealed plastic bag in a refrigerator for two to four weeks before sowing.
Sowing Canterbury Bells Seeds
Timing for sowing Canterbury Bells seeds depends on your desired planting method. For earlier blooms, starting seeds indoors is recommended in late winter or early spring, 10-12 weeks before the last frost. If direct outdoor sowing is preferred, wait until late spring or early summer after frost danger has passed. This allows plants to establish their foliage during the first growing season.
Seeds are small, so sow them on the surface of the pre-moistened seed starting mix. Lightly press seeds onto the surface to ensure good seed-to-soil contact, or cover with a thin layer of vermiculite, approximately 1/16th inch deep. Place trays or pots where the temperature remains consistently between 65-70°F (18-21°C) for optimal germination. Maintaining consistent moisture is crucial, achieved by regular misting or bottom watering.
Caring for Seedlings and Young Plants
After Canterbury Bells seeds germinate, providing adequate light is crucial to prevent leggy growth. Position seedlings under grow lights for 14-16 hours daily, a few inches above plant tops. If using natural light, place them in a bright, south-facing window, rotating trays regularly for even light exposure. Consistent moisture is important; water from the bottom or mist the soil surface to keep it damp but never soggy.
Once seedlings develop their first true leaves, thin them to ensure air circulation and reduce competition. Snip weaker seedlings at the soil line, leaving strongest ones 2-3 inches apart. When seedlings have developed two to three sets of true leaves, pot them into larger containers (e.g., 3 or 4-inch pots). This provides more space for root development and allows plants to grow larger before transplanting.
Before permanent outdoor placement, young Canterbury Bells plants must undergo hardening off. This gradual acclimation to outdoor conditions prevents transplant shock. Begin by placing plants in a sheltered, shady outdoor location for a few hours daily, gradually increasing sun and wind exposure over seven to ten days. After this hardening off period, young plants are ready for transplanting into their permanent garden location once frost danger has passed.
Ongoing Care and Bloom
Once established, Canterbury Bells thrive in full sun to partial shade (at least six hours of direct sunlight daily). They prefer well-draining, organic-rich soil. Amending heavy clay soils with compost improves drainage and plant health.
Routine watering is important, especially during dry spells, to keep the soil consistently moist but not waterlogged. A light application of a balanced granular fertilizer in spring supports robust growth. As biennials, Canterbury Bells typically form a low rosette of foliage in their first year, then produce their bell-shaped flowers in the second growing season (late spring to mid-summer). Deadheading spent flowers encourages more blooms and can extend the blooming period.
Canterbury Bells are resilient, but monitoring for pests like aphids or slugs helps maintain plant health. Prompt removal or organic treatments manage infestations. Allowing some spent flowers to remain facilitates self-seeding, ensuring a continuous display of these charming blooms in subsequent years.