Clematis terniflora or Sweet Autumn Clematis, is a deciduous to semi evergreen vine that is native to Japan. The dark green glossy compound leaves are arranged in opposing pairs with 3 to 5 leaflets that are 2 to 3 inches (5-7.5 cm) long. Vines can reach up to 30 feet (9 m) in length. Plants are very vigorous growers and need support to climb; the vines climb by twisting around supports or trees. Plants can become very invasive if they are not trimmed after flowering. Clematis terniflora is hardy in USDA zones 4-9.
Blooming Time: In late summer to mid fall, 2 inch (5 cm) long white flowers cover the vine. The flowers are sweetly scented. After flowering, the silvery feathery seeds are almost as attractive as the flowers. While this plant is in flower it is one of the showiest vines that I've ever grown.
Culture: Clematis terniflora grows best in full sun to partial shade. When grown in the greenhouse, we use a soil mix consisting of 2 parts loam to 1 part peat moss to 1 part sand. The plants are kept moist for optimum growth and fertilized monthly. I do not recommend growing these in a greenhouse; the plants will scramble over every plant that is growing nearby and require constant trimming to keep them in bounds. In the landscape in zone 7, the plants are semi evergreen and are well suited to Oklahoma's climate and soil. After flowering, plants should be cut back hard to stop the production of seeds.
Propagation: Clematis terniflora is best propagated from seed. Seeds collected in the fall should be sown in the soil where the plants are to grow.
Clematis terniflora was featured as Plant of the Week September 3-9, 2004.
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Cal's Plant of the Week was provided as a service by the University of Oklahoma Department of Microbiology & Plant Biology and specifically the late Cal Lemke, who used to be OU's botany greenhouse grower and an avid gardener at home as well. If the above links don't work, then try the overview site. You may also like to look at the thumbnail index. ©1998-2012 All rights reserved.