Growing Campanula (Bellflower)

Pronunciation: kam-pan'yew-luh

Variable late spring through summer blooms in shades of blue, lavender, violet, white, and pink. Heights range from 3″ to 30″, offering a Campanula for almost every garden situation—from rock garden front to perennial border back.

Light/Watering

Most do well in full sun or light shade (shade vital in South for all but C. persicifolia and C. pyramidalis). Prefer evenly moist, well-drained soils; best in climates with cool nights.

Fertilizer/Soil and pH

Thrive in average, well-drained soils pH 6–8. Benefit from one light application of balanced 10-10-10 fertilizer in early spring. Summer mulch keeps roots cool; keep mulch 1–2″ from crown to avoid rot.

Pests/Diseases

Generally pest-free. Watch for distorted growth or yellowing leaves signaling aphids—spray with insecticidal soap. Slime trails and ragged holes indicate slugs—intervene early with handpicking, traps, or barriers (diatomaceous earth, copper). Rust (reddish-brown pustules on leaf undersides): remove infected parts, treat with wettable sulfur next season. Crown rot (blackening base, rotting crowns): ensure good drainage, avoid overwatering/overcrowding, keep winter mulch away from crowns, destroy affected parts.

Companions

At home with Lamb's Ear (Stachys), Lady's Mantle (Alchemilla), Columbine, and Roses. Delicate form and cool colors complement many perennials.

Reflowering

Deadheading rewards longer bloom (tedious for small-flowered types). C. carpatica and C. lactiflora may be cut back by a third after flowering for sporadic rebloom. C. poscharskyana excels as ground cover even in dry shade; cut to 2″ after flowering. Deadhead C. persicifolia for longer flowering (tedious—remove each flower individually). After bloom, remove old stems to basal foliage.

Dividing/Transplanting

Divide C. carpatica every 2–3 years in early spring; C. persicifolia every 3–4 years. All Campanulas transplant in early spring or fall with sufficient soil and thorough watering.

End-of-Season Care

Leave basal growth on C. carpatica, C. poscharskyana, C. persicifolia for winter crown protection; cut dead/unattractive foliage in early spring. C. lactiflora foliage may be cut to 3″ in late fall.

Calendar of Care

• Early Spring: Light 10-10-10 or compost side-dress. Supplement nitrogen during prolonged rain. Water if unseasonably dry. If rust present last year, treat with wettable sulfur. Divide C. carpatica (2–3 yrs) and C. persicifolia (3–4 yrs).
• Mid-Spring: Watch for aphids, spray with insecticidal soap. Monitor slugs, control if present. Mulch as soil warms.
• Late Spring: Stake taller forms, especially in shade. Watch for crown rot (blackening, wilting) and treat. If rust pustules appear, remove infected parts, cut back foliage if disfiguring.
• Summer: Deadhead to encourage longer bloom. Use small scissors for small-flowered forms. Groom yellow/dead leaves. Alternatively cut C. carpatica and C. lactiflora back by one-third after flowering. Water during dry periods.
• Fall: Cut C. lactiflora foliage to 3″ above soil. Leave C. carpatica, C. persicifolia, C. poscharskyana intact over winter.