Getting it to bloom

Why won't my Harebell bloom? (and how to make it flower)

Also called Harebell, Bluebell of Scotland, Scottish Bluebell, Witch's Thimble (Campanula rotundifolia).

More about harebell

About Harebell

Campanula rotundifolia · also called Harebell, Bluebell of Scotland · flowering

Campanula rotundifolia is a delicate perennial wildflower native to temperate Europe, North America, and Asia, thriving in short turf, rocky outcrops, and dry grassland from sea level to alpine elevations. It is one of the hardiest bellflowers, tolerating USDA Zone 3 winters, and grows best in full sun with sharply drained, low-fertility soil — rich soil produces lush leaves but few flowers. Deadheading spent blooms extends the flowering season from July through September. Campanula species are listed as non-toxic to cats and dogs by the ASPCA.

Plant type: flowering

The reasons harebell isn't blooming

Almost every non-blooming harebell traces back to one of these, roughly in order of how common they are:

Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.
Too much nitrogen feed, driving lush foliage at the expense of flowers (very common with general or lawn feeds).
The plant has not been deadheaded, so it stops flowering once it sets seed.
Irregular watering — drought or waterlogging at the budding stage makes buds abort.
It is still too young or was checked by a transplant and is rebuilding before flowering.

Feeding harebell a high-nitrogen general feed and growing it in too little sun — you get a big leafy plant and almost no flowers.

The fix — how to get harebell to flower

Maximise sun. Give harebell the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers.
Switch the feed. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.
Deadhead regularly. Remove spent flowers often to keep it producing more rather than stopping to set seed.
Water consistently. Keep moisture even through budding and flowering — drought-then-flood swings make buds drop.

Light and feeding do most of the heavy lifting here. Dial in the spot with the light guide for harebell and get the feeding right with the harebell fertilising schedule — the wrong feed (too much nitrogen) is one of the most common silent reasons a healthy plant makes leaves instead of flowers.

Bloom season and what to expect

Harebell flowers across its growing season (mostly summer) and, kept fed and deadheaded, can bloom for many weeks or right up to frost.

Post-bloom care so it flowers again

Deadhead, keep feeding lightly, and many will rebloom; collect seed from the best plants at the end of the season if you want to grow them again.

For everything else this plant needs day to day, see the full harebell care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Harebell blooming — frequently asked questions

Why won't my harebell flower?

Harebell blooms on the season's growth given enough sun, warmth and the right feed — there is no cold or photoperiod trick, just good growing conditions and a bloom-leaning feed. The most common reason it is not happening: Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.

How do I make harebell bloom?

Give harebell the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.

When does harebell normally bloom?