How Deep Do You Plant Canterbury Bell Seeds?

Canterbury bells come in shades of blue, purple and white.

With bell-shaped flowers along spiky stems, Canterbury bells (Campanula medium) are an old-fashioned biennial flower that blooms in June and July. Because they are biennial, they will not produce flowers until their second year of life.

Outdoors

In mid to late August, mix seeds of Canterbury bells with fine sand to ensure more even distribution in the seed bed. Broadcast the sand-seed mixture on the garden bed with your hand. Firm the seed-sand into the surface of the soil by gently pressing down with the palm of your hand.

Indoors

Sow Canterbury bells seeds in 2-inch starter pots by sprinkling a pinch of seeds on the surface of the soil approximately two to four weeks before your average last spring frost. Gently press the seeds into the surface of the soil with your hand. Keep the pots at 70 to 80 degrees until germination occurs, in about 10 to 20 days.

Self-Seeding

To encourage your Canterbury bells to self-seed in your garden, stop removing spent flower heads beginning in mid to late July. The seeds will ripen and scatter themselves in the garden bed by late August. Tiny seedlings will emerge in late fall or the following spring, depending on your autumn weather.

References

• North Dakota State University Extension: How to Succeed at Seed Starting
• Ohio State University: Monthly Garden Tips
• Penn State University Extension: Sowing Annual Seeds

Resources

• National Climatic Data Center: Freeze/Frost Maps