Clematis (Virgin’s Bower)
Common name: Virgin’s bower
Forms of Clematis are, unquestionably, the most popular of all climbing shrubs. There are two basic types: the spring-flowering species with smaller blooms, and the ever-popular large-flowered hybrids that bloom from late spring to early autumn, depending on variety.
Popular species and varieties
One species that makes a fine show in the spring is Clematis montana, producing masses of white . Originating from the Himalayas, it is a vigorous plant that can grow to 5m (15ft) in height and spread. There are several named forms of Clematis montana, among them ‘Elizabeth’ (AGM), a soft pink. Another clematis that blooms in spring is the European Clematis alpina (AGM). The flowers are pendulous, cup-shaped and violet-blue. There are a number of varieties and one of the best is ‘Blue Dancer, a pale blue with long, narrow, twisted petals.
Early summer is when Clematis macropetala starts to flower, with nodding blue bell-shaped blooms. This species originates from China and Siberia, and grows to around 4m (12ft) in height’Maidwell Hall’ (AGM) is a good form, with deep blue flowers. ‘Markham’s Pink’ (AGM) is a rich rose pink
One species useful for later flowering is Clematis tangutica, producing yellow bell-shaped blooms in mid-summer.
For many, it is the large-flowered hybrids that have the most charm. These generally grow to around 3m (10ft) in height, with flowers, depending on variety, 10-15cm (4-6in) across. One is certainly spoilt for choice, with hundreds of varieties from which to choose. ‘Nelly Moser (AGM) is perhaps the best known, its large blooms being pink tinged with white, with a distinctive red stripe on each petal. Another with a free-flowering habit is ‘Mrs Cholmondley’ (AGM), a lovely pale blue. One that never fails to attract attention, with its large pure white blooms, is ‘Marie Boisselot’ (AGM). There are many nurserymen specializing in these plants; their descriptive, well-illustrated catalogues give an indication of the range available.
Soil type Clematis require good, well-drained, humus-rich,
Planting This can be done in the autumn or spring. Positioning is important, as clematis need an open spot, but with the base of the stem and the roots shaded from strong sun. This shade can be provided either by a low-growing shrub, or simply some large stones placed strategically. The junction where the stem merges with the root should be around 2.5cm (1in) below soil level,
Maintenance Pruning – when and how this is done depends on type. In the case of the spring-flowering varieties, prune immediately after flowering, generally carried out when space is restricted. Take out all the flowered shoots, and tie in the new growth. Those in this group include Clematis alpina, Clematis macropetala and Clematis montana, The large-flowered hybrids that bloom in early summer should be pruned from mid to late winter Shorten to the first pair of strong buds.
The varieties that flower from early summer should have their growth cut back hard in late winter; to a pair of strong buds 1m (3ft) or less above ground level.
With all clematis you should water freely in dry weather; and mulch with well-rotted compost in the spring.
Propagation Take semi-ripe cuttings 10cm (4in) long, in mid-summer. Space these cuttings around the edge of a pot containing an equal mixture of peat and sharp sand, Place them in a frame, preferably a propagating frame, with bottom heat When rooted, pot them individually and overwinter them in a frost-free greenhouse. Move them into larger pots in the spring. The new plants should be ready to go out in the autumn.
Pests and diseases Aphids, earwigs and slugs can attack new growth; control with appropriate preparations.
Clematis wilt: This fungal disease shows itself by the sudden collapse of the plant. If this happens, cut it out immediately. Usually, new shoots will emerge later in the season or the following spring.
Mildew: This can be present; treat with a fungicide. Virus-infected clematis will show mottled and distorted foliage. Unfortunately there is no cure, so the plant should be dug out and burnt.