The bellflowers consist of a genus of about 300 species plus innumerable cultivars. They are ornamental plants grown mainly as perennials, but with a handful of annual and biennials.
The majority are grown as border plants, but there is a number of trailing forms used in hanging baskets and other containers. The main border plants are upright, some plants reaching 1.2m (4ft) or more. Other are dwarf, carpeting plants, some rising no more than 1cm (1/2in) from the ground.
The characteristic of most of them is their bell-shaped flower. This can vary in size from 5cm (2in) or more down to just a few millimetres in the case of some rock-garden plants. The typical colour for most bellflowers is blue but, as with most blue flowers, there are also white and a few pink variants. Although the foliage is attractive, without being too noticeable, it is the flowers for which the plants are grown.
They can be grown on a wide variety of soils. Most will grow in full sun, but there are a few woodlanders which prefer, and, indeed, look best in, a dappled shade. Some of the more choice alpine varieties are difficult to grow in the open bed and are best gown in pots, preferably in an alpine house.