There are keen gardeners who like to cultivate many different variants of the same species, rose growers are an obvious example, but much as I love all clematis, there's only one that captured my imagination long ago and it is still the only one for me even now.

Flowers all summer

The much sought after Clematis sieboldii was introduced into Britain from Japan during the nineteenth century. It flowers continuously from late June right through to September with flowers which are up to 4in (10cm) across.

Beautiful white saucer-shaped sepals embrace double flowers which form a domed central boss. Magnificent violet-purple petal-like stamens marry the sepals and flowers together. Each petal also carries a contrasting central green stripe.

The flowers are borne singly in great clusters, bees love them and their star-like shape and striking colours make these unusual blossoms look like those of the more tender Passion Flower.

Planting and care

The dark green biternate leaves of Florida Bi-Colour are composed of nine leaflets and form the perfect sombre backdrop for such a bright and vivid bloom. The growth is slender, reaching up to 7-9 feet (2-3 metres), and generally considered deciduous, though it could be classified as semi-evergreen during a mild winter.

Growing well in a container, its best location is on a south or south-west facing wall with a trellis to give it support. When planting use loam, peat, and a little bone meal and plant at least 2in (5cm) above the top of the rootball at below soil level.

Clematis Florida Bi-Colour produces all its flowers on the current season's growth, so should be pruned hard every March.