PL. —Campanula rotundifoliaBotanical illustration — drop image
Campanula rotundifolia

Harebell

SpringSummerFall
2a7bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Peak bloom
Summer
In bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

Campanula rotundifolia is a slender-stemmed herbaceous perennial native across temperate regions of the Northern Hemisphere, from rocky outcrops and cliff ledges to open grasslands and dry meadow edges. Its violet-blue, nodding bell-shaped flowers appear from midsummer into early fall, making it one of the later-blooming wildflowers in its range. It is the floral emblem of Sweden and is commonly known as bluebell in Scotland.

Harebell thrives in lean, sharply drained soils and tolerates thin, rocky, or sandy ground where richer competitors cannot establish. Fertile soil encourages floppy stems and reduced flowering; avoid amending planting sites with compost. It spreads by short rhizomes and self-seeds at a modest rate, building a small colony over a few seasons without becoming invasive. It is well-suited to rock gardens, dry meadow plantings, and naturalized bank edges. Cold hardiness is exceptional for a herbaceous perennial.

Young basal leaves and flowers are edible; leaves can be eaten raw in salads and flowers used as a garnish.

Care guide
SunFull sun to part shade
WaterLow
SoilWell-drained, lean, sandy or rocky
Spacing6–12 in
Height6–18 in
Zone2a – 7b
Native RegionAK, AZ, CA, CO, CT, ID, IL, IN, IA, KS, ME, MD, MA, MI, MN, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OR, PA, RI, SD, UT, VT, VA, WA, WV, WI, WY
Direct sowFrost hardy
Seasonal tasks
winter
sowSurface-sow seeds indoors on moistened seed-starting mix; do not cover — seeds need light to germinate. Hold at 65–70°F for 2–3 weeks until seedlings emerge.
spring
cutDivide congested clumps in early spring before stems extend beyond a few inches. Replant divisions immediately in sharply drained, unamended soil.
sowTransplant seedlings outdoors, or direct-sow into a prepared lean seedbed, after the last frost date. Press seeds firmly onto the soil surface without covering.
summer
watchMonitor for powdery mildew during warm, dry spells with cool nights. Improve airflow between plants and avoid overhead watering if white coating appears on foliage.
cutTrim spent stems by half after the first flush of flowering to encourage a second round of buds extending into early fall.
fall
watchAllow selected stems to mature and scatter seed if naturalizing a colony. Cut remaining stems to the base once flowering is fully finished.
Common problems

Powdery mildew

Symptoms

White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.

Treatment

Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.

Botrytis (grey mould)

Symptoms

Grey fuzzy mould on petals and stems, worst in cool wet conditions.

Treatment

Remove affected parts immediately. Improve air circulation. Avoid overhead watering. Apply copper fungicide if severe.

Fungal leaf spot

Symptoms

Brown or purplish spots on the leaves, often ringed with a yellow halo, that spread and merge in warm, humid, or wet weather; heavily spotted leaves yellow and drop early.

Treatment

Pick off spotted leaves and clear fallen debris to remove overwintering spores. Improve air circulation by thinning, and water at the base so foliage dries quickly. If it persists, apply a copper- or sulfur-based fungicide at the first sign.