| Clematis florida var. sieboldiana (photo Sz. Marczyński) |
 Clematis florida var. sieboldiana (photo Sz. Marczyński) |
 Clematis florida var. sieboldiana (photo Sz. Marczyński) |
 Clematis florida var. sieboldiana (photo Sz. Marczyński) |
 Clematis florida var. sieboldiana (photo Sz. Marczyński) |
 Clematis florida var. flore-pleno (photo Sz. Marczyński) |
Szczepan Marczyński
Clematis florida are more suitable for connoisseurs or very conscientious gardeners rather than for beginners looking for immediate effect. When planting them you should remember to choose a warm sheltered place and provide a very good drainage. Afterwards, you must supply them with plenty of water and carefully protect against cold in winter, but I can assure you that they are well worth all the trouble.
Clematis florida is native to south and southeast China. It has been cultivated in the gardens in Japan since the 18th century and came to Europe in 1776, brought by Thunberg. It has thin, brittle, woody stems that are lengthwise ribbed and reach up to 2 m. It climbs by means of leaf petioles that twine round the supports. Leaves are generally semi-evergreen, made up of 3-9 lanceolate or ovate leaflets that are deep green during the growth period, and change color to purple-green in autumn.
Flowers of 5-10 cm across are set singly on long stems (10-15 cm) growing out of leaf axils. They comprise 4 to 8 oval, slightly wavy edged tepals which are creamy white and have a pale green central bar on the outer side. In autumn flowers turn slightly greenish. The striking appearance of the blooms is due to its unusually long contrasting stamens consisting of deep crimson-purple, almost black anthers set on filaments that are white at the base and violet at the top. The blooms are borne on new wood - in the garden from June to September, and in a frost-free place - from early May to the end of December. They both open and fade slowly, staying attractive for several weeks.
There are two cultivars of the species that are most commonly encountered in cultivation:
Clematis florida var. flore-pleno (syn. Clematis florida 'Alba', 'Alba Plena', 'Plena', 'Flore Pleno') boasts the most double and arguably the most beautiful flowers of all double flowered clematis. They are of 8-10 cm across with white tepals arranged in a very regular rosette pattern. All the stamens are converted into staminodes that are almost identical with tepals - lanceolate, white, sometimes shaded with green (especially in autum) and have a pale green central bar on the outer side. The growing habit, foliage and flowering period is similar to those of the species. According to Christopher Grey-Wilson it can be found growing in the wild in the mountains of the southeast part of the Yunan Province, China, scrambling through scrub at an altitude of about 1700 m. It's been grown in the gardens in Japan for centuries and was brought to Europe in 1835.
Clematis florida var. sieboldiana (syn. Clematis florida var. bicolor, 'Bicolor', 'Sieboldii', 'Sieboldiana') is considered by many as the most extraordinary of all clematis. It has unusual and very attractive flowers of 10-12 cm across, comprising oval creamy-white tepals, often with a greenish bar along the center, and violet staminodes (stamens transformed into a calyx). Staminodes can vary in length and shape, but they are always slimmer and shorten than tepals. The growing habit, foliage and flowering period is similar to those of the species. This cultivar was brought to Europe from Japan by Phillipp van Siebold (after whom it is named) and was planted in the Botanic Garden in Leiden (Holland).
Both Clematis florida var. flore-pleno and Clematis florida var. sieboldiana have a tendency to produce mutations (sports) that make them resemble one another. You can often find the plants bearing flowers of both cultivars. Sometimes even one flower can possess characteristics of both cultivars, half of it looking like Clematis florida var. flore-pleno, and the other like Clematis florida var. sieboldiana.
Clematis florida and its cultivars should be pruned hard as they produce flowers on new wood. They require moist but well drained soil and a warm, sunny and wind-sheltered position. They might freeze in harsh winters so you shouldn't plant them in the regions with severe climate and in frost hollows. After planting you should top the ground with bark and further protect it with a layer of coniferous twigs. All the above-described clematis are perfect for a secluded site with plenty of sun e.g. next to a vigorous evergreen bushes. They are also suitable for growing in large containers, which allows you to move them into a cool but frost-free place (a cool greenhouse, a verandah or a winter garden) in autumn where they will continue blooming even till the end of December and keep their foliage to spring.
Clematis florida and its cultivars are ideal for interior decoration as cut flowers, staying fresh even up to 2 weeks.
Unfortunately they are difficult to propagate and their nursery cultivation is quite troublesome so in effect they are hard to find in trade. It's best to look for them in the nurseries and garden centers specializing in a wide assortment of plants.
 Clematis florida var. sieboldiana (photo Sz. Marczyński) |
 A plant with the flowers of both Clematis florida var. flore-pleno and Clematis florida var. sieboldiana (photo Sz. Marczyński) |