Grow in fertile, medium moisture, well-drained soils in full sun to part shade. Vining hybrids are best sited in locations where the flowering parts of the vine are in sun to part shade but the roots are shaded. Some light afternoon shade is usually beneficial in hot and humid summer climates such as the St. Louis area. Clematis vines need a trellis or other support on which to grow. Roots should be kept cool, shaded and uniformly moist. Root areas may be shaded with perennials, annuals or small shrubs. A thick root mulch is appreciated. Do not allow soils to dry out.
'Jackmanii' can be pruned as Group 2 or Group 3. See pruning instructions below.
Clematis is a genus of over 250 species, most of which are woody to semi-woody deciduous vines climbing by twining leaf stalks or in some cases trailing over support, but in a few cases grow as freestanding or sprawling herbaceous perennials and small deciduous or evergreen shrubs. Most have flat, cupped or bell-shaped flowers. Some plants feature ornamental fluffy seed heads in autumn. Plants bear opposite, simple to compound leaves which are usually deciduous but sometimes evergreen. Compound leaves range from lobed to trifoliate to biternate to pinnate to bipinnate. Clematis is native to both the Northern and Southern Hemispheres including Europe, the Himalayas, China, Australasia, North America and Central America.
Plants are often divided into three groups based on pruning needs.
Group 1 – Flowers only on old wood (previous year). Prune after spring flowering.
Group 2 – Flowers on both old and new wood. Typically, little pruning should be done for woody-stemmed members of this Group. If cut to the ground or pruned in fall or spring, flowering will be reduced or delayed but not prevented.
Group 3 – Flowers only on new wood. Can be cut to the ground in fall or spring.
Genus name comes from the Greek word klematis which is an old name applied to climbing plants.
'Jackmanii' features profuse, 5-7", open, four-sepaled, violet-purple flowers cover this vine in mid to late summer. An old favorite which was introduced in England in the mid-1800s.
No serious insect or disease problems. Susceptible to wilt/stem rot (can be fatal), powdery mildew, leaf spots, rust and viruses. Potential insect pests include aphids, vine weevils, slugs/snails, scale and earwigs. Watch for spider mites.
Clematis can be trained to climb a wall, trellis, fence, arbor, porch, lamppost or other stationary structure. They provides good architectural height and framework for small gardens. They can also be planted to sprawl over and through shrubs, scramble over old stumps or simply as a ground cover in conjunction with other flowering perennials. Containers.