Campanula glomerata (clustered bellflower) — Clump-forming, mat-forming or upright depending on species

Overview

Campanula glomerata is a clump-forming, mat-forming or upright depending on species perennial in the genus Campanula, part of the Campanulaceae family, with deciduous or semi-evergreen; basal rosettes of rounded or heart-shaped leaves, narrower up the stem foliage. It typically grows around 1.0 m tall. Campanula glomerata grows best in full sun to partial shade, and tolerates loam and chalk or sand; most tolerate poor soils soils and neutral to alkaline pH. Its UK hardiness is rated H5-H7. Suggested uses include borders, rock gardens and wildflower meadows. It is native to Europe and temp. Asia.

About

Campanula glomerata is a perennial in the Campanulaceae that forms clumps, mats or upright tufts and produces tight terminal clusters of flowers. It grows to about 1.0 m and carries basal rosettes of rounded or heart-shaped leaves, with narrower leaves up the stem. Flowering runs from June to September, when heads of dark violet-blue to purplish-blue bells appear. It suits positions in full sun to partial shade on neutral to alkaline soils.

Wikipedia contributors, CC BY-SA 4.0 — Campanula glomerata

About the genus

Campanula is the type genus of the Campanulaceae family of flowering plants. Campanula are commonly known as bellflowers and take both their common and scientific names from the bell-shaped flowers—campanula is Latin for "little bell".

Wikipedia contributors, "Campanula", CC BY-SA 4.0 — Campanula

In the garden

Campanula glomerata belongs to the bellflower genus Campanula and is native to Europe and temperate Asia. Plants present a clump-forming or mat-forming habit, reaching roughly 1.0 m, with basal rosettes of rounded or cordate leaves and narrower cauline foliage. Flower heads are carried at the stem tops and appear in a concentrated display between June and September. Position the species in full sun to partial shade; it tolerates exposed or sheltered sites and will grow on loam, chalk or sand and most poorer soils so long as moisture is not stagnant. Soil pH should be neutral to alkaline, and the general requirement is moist but well drained — by contrast, alpine forms demand much sharper drainage. Hardiness ranges from H5 to H7, equivalent to hardy through fully hardy for UK gardens. Campanula glomerata fits borders, rock gardens and wildflower meadows where you want mid- to late-summer clusters of bell-flowers. It copes with a variety of aspects except deep shade, and its terminal flower clusters make it useful where upright summer structure is required. Expect stems topped by grouped violet-blue bells from June to September.

Growing conditions

Best soil and position for Campanula

Sunlight: Full sun to partial shade
Soil type: Loam, chalk or sand; most tolerate poor soils
Soil pH: Neutral to alkaline
Soil moisture: Moist but well drained; alpine kinds need sharp drainage
Aspect: Any except deep shade
Exposure: Exposed or sheltered
UK hardiness: H5-H7

Plant details

Campanula glomerata size, habit and characteristics

Plant type: Perennial
Habit: Clump-forming, mat-forming or upright depending on species
Foliage: Deciduous or semi-evergreen; basal rosettes of rounded or heart-shaped leaves, narrower up the stem
Height: 1.0 m
Suggested uses: Borders, rock gardens, wildflower meadows
Native to: Europe, temp. Asia

Care notes

Pruning and caring for Campanula glomerata

Cultivation: Undemanding given drainage and a reasonably open position. The taller border kinds are worth supporting early, since heavy rain will flatten a flowering stem and it will not lift again. Deadheading extends the season considerably, and the vigorous spreading species are best sited where they can run without swamping smaller neighbours.
Pruning: Cut flowered stems back to basal growth to encourage a second, lighter flush. Tidy remaining foliage in late autumn, or leave the rosettes intact over winter on alpine kinds.
Propagation: Divide in spring or autumn, and take basal cuttings in spring for named cultivars. Species come readily from seed sown fresh, and several self-sow where conditions suit.
Pest resistance: Slugs and snails are the real problem, particularly on emerging spring growth and on alpine rosettes.
Disease resistance: Generally healthy; rust and powdery mildew appear on crowded or drought-stressed plants.

Frequently asked questions

How do I grow Campanula glomerata?

Undemanding given drainage and a reasonably open position. The taller border kinds are worth supporting early, since heavy rain will flatten a flowering stem and it will not lift again. Deadheading extends the season considerably, and the vigorous spreading species are best sited where they can run without swamping smaller neighbours.

Where is the best place to plant Campanula glomerata?

Campanula glomerata prefers full sun to partial shade. It suits exposed or sheltered positions.

What soil does Campanula glomerata need?

Campanula glomerata grows best in loam and chalk or sand; most tolerate poor soils soil. It prefers neutral to alkaline soil. Aim for soil that stays moist but well drained; alpine kinds need sharp drainage.

How do I prune Campanula glomerata?

Cut flowered stems back to basal growth to encourage a second, lighter flush. Tidy remaining foliage in late autumn, or leave the rosettes intact over winter on alpine kinds.

How big does Campanula glomerata grow?

Campanula glomerata reaches a height of 1.0 m.

Is Campanula glomerata hardy in the UK?

Campanula glomerata has an RHS hardiness rating of H5, meaning it is hardy in most of the UK, tolerating -15 to -10°C.

How do I propagate Campanula glomerata?

Divide in spring or autumn, and take basal cuttings in spring for named cultivars. Species come readily from seed sown fresh, and several self-sow where conditions suit.

More in the Campanula genus

Browse all Campanula →