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

Overview

Campanula glomerata 'Superba' 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 'Superba' 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 cottage gardens. It is native to Belgium, Flemish Region and Walloon Region.

About

Campanula glomerata 'Superba' is a perennial bellflower that forms clumps to about 1.0 m and bears basal rosettes of rounded to heart-shaped leaves with narrower leaves up the stem. It produces summer flower clusters from June to September. Best in full sun to partial shade on neutral to alkaline loam, chalk or sandy soils that are moist but well drained. Rated H5–H7, it tolerates exposed or sheltered sites and suits borders, rock and cottage gardens.

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 'Superba' is a clump-forming perennial in the Campanulaceae family, originating from regions of Belgium. It reaches roughly 1.0 m and carries basal rosettes of rounded or heart-shaped leaves, with narrower leaves higher on the stems. Flowering runs from June to September, when the plant produces its characteristic clustered blooms. Position it in full sun to partial shade; avoid deep shade. Soil should be neutral to alkaline and moist but well drained — loam, chalk or sand are acceptable and many plants tolerate poorer soils. Note that alpine forms of Campanula need much sharper drainage, but 'Superba' performs well on ordinary garden soils provided they do not remain waterlogged. The plant suits both exposed and sheltered locations and is rated H5–H7, meaning it is hardy through typical UK winters and can be grown across most garden situations. Use 'Superba' in mixed borders, cottage-style plantings or rock garden edges where its summer flowering adds vertical interest at about 1.0 m. To keep clumps neat, remove spent flowering stems alongside a light tidy of the basal rosette; this helps maintain the plant's habit and encourages a cleaner display in following seasons.

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 'Superba' 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, cottage gardens
Native to: Belgium, Flemish Region, Walloon Region

Care notes

Pruning and caring for Campanula glomerata 'Superba'

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 'Superba'?

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 'Superba'?

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

What soil does Campanula glomerata 'Superba' need?

Campanula glomerata 'Superba' 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 'Superba'?

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 'Superba' grow?

Campanula glomerata 'Superba' reaches a height of 1.0 m.

Is Campanula glomerata 'Superba' hardy in the UK?

Campanula glomerata 'Superba' 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 'Superba'?

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 →