For many garden favorites, growing from seed can be a total headache—and sometimes, they don’t even sprout at all! But I’ve got some good news for you: Bellflowers (Campanula) are a different story. They’re actually pretty easy to start from seed, and in many gardens, they’ll even happily self-sow on their own.
Heads Up: Most Are “Dark Germinators”
When you’re ready to get planting, there’s one big thing to keep in mind: most bellflower varieties are “dark germinators.” This means you can’t just scatter the seeds on top of the soil at your chosen planting spot and call it a day. You’ll need to make sure they’re tucked in under at least half an inch of soil to get them to sprout.
A Popular Exception to the Rule
Of course, there’s always an outlier! The Canterbury Bell is a fan favorite because it’s hardy and reliable, but it’s actually a “light germinator.” If you’re planting these, do not cover the seeds with soil—they need light to wake up and start growing.
How to Get it Right
If you’re planning on sowing your seeds directly into the garden bed, wait until after the last frost in May. Even the hardiest varieties don’t handle late-night frosts very well when they’re just tiny seedlings.
If you want to see those beautiful blooms in your first year, I highly recommend starting them indoors. Here’s my simple step-by-step guide:
- Fill your seed trays with a low-nutrient seed-starting mix.
- Lightly mist the soil with a spray bottle so it’s damp but not soaked.
- For dark germinators, tuck the seeds about half an inch deep. For light germinators, just press them onto the surface.
- Place your trays in a bright spot, but keep them out of direct, harsh sunlight.
Pro tip: You can use a clear plastic cover or humidity dome to speed things up, though it’s not strictly necessary. Once the threat of frost has passed in mid-to-late May, your babies are ready to be moved to their permanent home in the garden!