Annual and biennial campanulas

Rising from clumps of hairy leaves, upright, bristly stems are loosely arranged with bonnet-like flowers in shades of pale blue or lilac, pink, pale lemon and mauve in spring and summer. Flowers of some campanula such as Campanula medium have a saucer-like base, leading to their common name of Canterbury bells.

Grow these campanulas in any well-drained soil in sun or partial shade. They often do well in stony soil.

Extreme conditions are unsuitable – very wet or acidic soils, deep shade, or very dry soil in strong sunlight, which can bleach out delicate flower colours.

Though it’s usual to sow biennials in summer to produce plants for flowering next year, they can also be sown under cover in late winter to flower the same year.