Culture
Easily grown in average, medium, well-drained soil in full sun to part shade. Unlike almost all other species of clematis, this plant will thrive and bloom well in considerable shade. Blooms on new growth. Prune hard in fall after flowering or in early spring. This clematis can be quite aggressive and will self-seed readily.
Noteworthy Characteristics
Clematis terniflora, commonly called sweet autumn clematis is a fragrant fall-bloomer. It is a vigorous, deciduous, twining vine with an extremely rampant growth habit. If given support, it will climb rapidly with the aid of tendrilous leaf petioles to 20-25' in length. Without support, it will sprawl along the ground as a dense, tangled ground cover (to 6-12" tall and 10' wide) which typically chokes out most weeds. Features aromatic, 1" diameter, cruciform, pure white flowers (each with 4 narrow petal-like sepals) in terminal panicles from late August to October in a profuse bloom which typically covers the foliage. Flowers give way to attractive, plume-like seed heads. Compound, leathery-textured, shiny green leaves (3-5 oval to elliptic leaflets with cordate bases). Sweet autumn clematis can aggressively self-seed in the landscape, and has escaped cultivation and naturalized in many parts of the U.S., particularly in the East and Midwest. Synonymous with and sometimes sold as C. maximowicziana, C. paniculata and C. dioscoreifolia, although technically C. paniculata is a separate species native to New Zealand.
Genus name comes from the Greek word klematis which is an old name applied to climbing plants.
Specific epithet means flowers in 3's.
Problems
Clematis wilt is a potentially fatal fungal disease that can affect any clematis, but large-flowered, hybrid varieties are the most susceptible. Powdery mildew, leaf spots, rust and viruses can also be problematic. Potential insect pests include aphids, vine weevils, slugs/snails, scale and earwigs. Watch for spider mites. Spreading, sometimes hard-to-control vine.
Uses
Trellises, arbors, posts, fences. Can also be allowed to sprawl along the ground as a dense ground cover to hide old tree stumps or other eyesores. Can also be grown through large shrubs, but growth must be monitored to insure that the shrub is not overwhelmed.