916 Clematis hybridsCommon Names: Jackman clematis, hybrid clematis Family: Ranunculaceae (buttercup or crowfoot Family)
There are more than 400 named cultivars of hybrid clematis created by crossing and back-crossing among some 200 wild species from China, Japan, Europe, Australasia, Africa and North America. The Jackman group of hybrids includes the original cross, Clematis X jackmanii, between Clematis lanuginosa and C. viticella, as well as dozens of hybrids and selections developed by using it as one of the parents. Members of the Jackman group of clematis produce flowers on the current season's growth, and therefore bloom later in the season than do clematis cultivars that produce their flowers on the previous season's growth. The Jackman cultivars climb with twining stems and cling with leaf stalks that twist and clasp. With good support, vines can reach a length of 10 ft (3 m) in a single growing season. The vines are semiwoody and the deciduous leaves are trifoliate or simple, opposite, and 2-4 in (5-10 cm) long. The spectacular flowers are abundant and large, to 7 in (17.8 cm) across, with 4-6 petal-like sepals, each about 2 in (5 cm) long. Produced from midsummer until first frost, flowers of the various cultivars may be single or double and come in a rainbow of colors. They are saucer shaped and face up and outward, proud of their singular beauty. The fruit is a very distinctive achene (dry, 1-seeded capsule) with a 2 in (5 cm) long silver gray wispy "tail" covered with long silky hairs. They are packed in long lasting fluffy clusters.
Only a brief list of selections, demonstrating the range of available flower colors, is given here. 'Alba' - pale gray double flowers; 'Rubra' - plum red double; 'Purpurea Superba' - dark, velvety purple; 'Comtesse de Bouchard' - rose pink; 'Mrs. Cholmondelay' - pale blue; 'Red Cardinal' - crimson.
Clematis X jackmanii was created at the Jackman and Sons nursery in Surrey, England, in 1858 by crossing C. lanuginosa from China with C. viticella from southern Europe. Many additional crosses and selections have been made since at various gardens in Europe and North America.
CultureSince Jackman clematis produces flowers on the current season's growth, they should be pruned to the ground in late winter or early spring before new growth begins. Light: Clematis hybrids do best with their foliage in full sun or partial shade, and their roots in constant full shade. Plant clematis in the shade of a rock or other structure, or grow other low, leafy plants over the root zone. Clematis do best with an eastern exposure so they are protected from the strongest midday sun. Moisture: Clematis need plenty of moisture during their growing season. They do best in light, loamy soil that drains rapidly. Hardiness: USDA Zones 4 - 9. It is important to keep clematis roots cool even as the vine itself is in full sun. Propagation: The best way to propagate clematis hybrids is by layering in spring or early summer. Simply bend a section of stem a short distance from its tip, twist or scratch it at the bend, and bury the bent, injured part in the ground. In a few weeks roots will have formed and the new plant can be severed from its parent. Allow to develop more roots on its own before transplanting to a new location.
Grow Jackman and other hybrid clematis on a trellis, wall or fence. Let it scramble over a rock wall or twine over an arbor. Many gardeners plant clematis at the base of a rose or other shrub and let it climb up and through the branches. Use an early blooming shrub or rose as a host for the late blooming clematis. Jackman clematis politely refrains from dominating its host. As cut flowers, the large blooms of Jackman clematis make an attractive table piece floating in a bowl of water. The curious fruiting heads, clusters of fluffy gray featherlike filaments, are long lasting and very effective in dried arrangements.
Clematis X jackmanii was the first of the large-flowered clematis hybrids, and it and its subsequent selections and hybrids are still the most popular varieties.
Steve Christman 2/9/01; updated 8/20/03, 7/24/04, 6/9/11