How to Grow Bellflowers: The Complete Guide to Campanula

When to Plant Bellflowers

Bellflowers can be planted outdoors once the spring frosts have passed. Perennial varieties can also be planted 4-6 weeks before the fall frosts to allow time for new roots to establish before the plant goes dormant. Harden off potted plants for a week prior to transplanting.

Where to Plant Bellflowers

Bellflowers enjoy full to partial sunlight and will thrive in the dappled light at the edge of the woods. In the warmer areas of their range, plant them in locations with afternoon shade to give them a break at the hottest time of the day. They aren’t picky about soil conditions, except that they need well-draining soil. Be careful not to plant in water-logged areas. A neutral pH range is fine.

Use bellflowers to provide the garden with those hard-to-find blue hues, setting off the more common yellows and oranges.

How to Plant Bellflowers

Bellflowers are easy to find at nurseries and garden centers in spring and can be ordered in small pots online. Plant potted bellflowers just as you would other small annuals or perennials, taking care to choose the appropriate location. Spacing will vary depending on the mature size of the cultivar you selected.

For established plants:

• Prepare the area by removing roots, rocks, and weeds. Loosen the soil and work in a few handfuls of compost.
• Dig a hole as deep as the root ball and twice as wide.
• Remove the bellflower from its container and prune any circling or girdling roots.
• Place the bellflower in the hole to check the depth—it should rest evenly with the ground surface.
• Backfill the hole, ensuring no air pockets form around the roots.
• Water thoroughly, then apply mulch around the plant to hold soil moisture and keep weeds down.

To start Bellflowers from seed indoors:

• Begin 6 to 8 weeks before your last frost in spring.
• Sow bellflower seeds in trays or cell packs in a standard seed starting mix.
• Lightly cover seeds with a dusting of vermiculite, but don’t bury them—they need light to germinate.
• Cover the tray with a humidity dome or plastic wrap to preserve moisture until germination, then remove the cover.
• Harden off seedlings prior to transplanting outdoors.