As perhaps can be gathered from the name, this is a particularly fine variety of the clustered bellflower. Campanula glomerata 'Superba' produces spectacular heads of rich purple-violet bell flowers. The flowers forming dense, globe shaped clusters on tall stems with rosettes of oval, mid-green leaves.
An easy to grow and reliable plant which performs well in full sun or partial shade in many soil conditions, it will spread to make a solid mat of foliage and will often bloom again in late summer if dead-headed promptly.
The vigour and toughness of Campanula glomerata Superba make it a popular plant. Flowering June to August and growing to around 50 to 60cm (20 to 24in) tall, this beautiful bellflower is perfect for a sunny, cottage-style or herbaceous border and is equally happy in partial shade.
Campanula glomerata 'Superba' has been awarded the RHS Award of Garden Merit (AGM).
Sow in early spring to early summer, otherwise sow in autumn, September or October
The seeds should be sown on the surface of the compost, press lightly into the compost but do not cover as they need light to germinate. The compost should be kept moist at all times.
Cover the seed container with a piece of glass or clear plastic and leave in a temperature of around 18-20°C (65-68°F) in a position which receives diffused light.
Germination between 14 and 28 days. Once some of the seeds have germinated air should be admitted gradually otherwise the seedlings may damp off. When seedlings have their first pair of true leaves and are large enough to handle, transplant into 7.5cm (3in) pots. When large enough, plant out into their final position.
Avoid planting out seedlings until all threat of frost has passed.
During the growing season water freely and apply a balanced liquid fertiliser each month. Cut back after flowering both to prevent self-seeding and to encourage a second flush of flowers, although they won't be as profuse as the first.
It may require some staking if planted in more exposed areas. Stake plants before the flowers open to keep the flowers upright.
Flowerbeds, borders and massed plantings
The species Campanula glomerata is a European native, from Turkey and parts of Asia. It is present almost everywhere except the extreme north.
The plant can be found in forests or dry grasslands, in scrub and open woodland, in grassy but not too wet places, in the edges of woods and along the margins of roads and trails. It prefers calcareous soils, at an altitude up to 1,500 m (4,921 ft) above sea level.
The genus name campanula is derived from the Italian campana meaning 'bell' and refers to the shape of the flowers. The word is from Late Latin around 1630's, campana, originally meant 'a metal vessel made in Campania,' the region around Naples. All Campanulas have bell-shaped flowers, although the flower forms vary considerably.
The species name glomerata means globular, it is taken from the Latin for 'small, round ball' referring to the shape of the clustered blooms.
The variety name Superba simply means superb.
The National Collection:
In the UK the National Collection of Campanulas is held at Burton Agnes Hall in East Yorkshire and the National Collection of Alpine Campanulas at Langham Hall in Suffolk.
- Additional Information
Packet Size 35mg Average Seed Count 400 Seeds Family Campanulaceae Genus Campanula Species glomerata Cultivar Superba Common Name Clustered bellflower Hardiness Hardy Biennial Flowers Purple-violet bell flowers Natural Flower Time June to August Height 40-60cm (16-24in) Spread 60-90cm (24-36in) Position Full Sun to Partial Shade. Soil Well-drained/light, Chalky/alkaline fertile, moist, neutral to alkaline soil