Sweet Autumn Clematis, Clematis terniflora

Sweet autumn clematis in full bloom.

Sweet autumn clematis, Clematis terniflora is a vigorous woody vine in the buttercup family (Ranunculaceae) native to Japan sometimes sold as C. maximowicziana, C. paniculata and C. dioscoreifolia (however, C. paniculata is really a different fall-blooming species native to New Zealand). This deciduous perennial that is hardy in zones 4-9 was introduced in 1877 as seeds sent to the Arnold Arboretum in Boston. Blooming in the fall, it often goes unnoticed until it blooms. Because C. terniflora aggressively self-seeds and has escaped cultivation in many parts of the U.S. is to invade forest edges, right-of-ways and areas along streams and roads, it is often considered an invasive species – particularly in the East and Midwest – and is no longer recommended as a landscape plant in many states. In Wisconsin it is not a regulated invasive plant on the DNR NR-40 list, but still should be used with caution. Before planting check to be sure that sweet autumn clematis is not invasive where you live.

The edges of the leaves of C. terniflora are smooth (L) while those of the native C. virginiana are serrated (R).

The similar-looking, but not very fragrant, Virgin’s-bower, C. virginiana, native to eastern North America blooms about the same time, and could be used instead, but is not as readily available in the horticulture trade. It is normally dioecious (separate male and female plants) so a single plant will not produce seed, but it, too, will produce plenty of seed where there are multiple plants and reseeds readily. Both the exotic and native vines can be sold under the same common name, sweet autumn clematis, so examine the leaves to determine which plant you are really purchasing. The leaf edges of C. virginiana are serrated or toothed while those of C. terniflora are mostly entire (smooth).

Climbing hydrangea might be a substitute for sweet autumn clematis.

The foliage of C. virginiana tends to be lighter and its flowers are hairy on the underside and bloom later, but those characteristics may not be useful when purchasing a plant in a container. Climbing hydrangea, Hydrangea anomala subsp. petiolaris,is another possible substitute, with faintly fragrant flowers (some suggest the scent is unpleasant) blooming earlier in the season.

Sweet autumn clematis has shiny green foliage with generally three leaflets in each compound leaf.

C. terniflora can grow up to 30 feet long, overwhelming everything in its path. The shallowly-grooved stems grow from a tap root, starting out green and developing light brown, longitudinally shredded bark on mature stems. The opposite leaves are a shiny green, with each leathery, pinnately compound leaf having 3-5 oval to elliptic leaflets. The apically round and basally cordate leaflets can be toothed on young plants but are entire when mature. The tendrilous leaf petioles on this twining vine twist around, helping it climb on structures or woody plants.

As the common name suggests, this plant blooms in late summer or fall. By mid-summer tiny buds begin to show and in the upper Midwest start to open typically in August and September. Although the individual star-shaped flowers are only about an inch across, the plant is very florific, with the flowers nearly completely covering the foliage so it is very showy. The numerous fragrant flowers are produced in terminal branching panicles of 3-12 flowers. Each monoecious flower has four pure white, narrow, petal-like sepals, approximately 50 stamens, and 5-10 pistils with long, plumose styles. The flowers are attractive to insects, especially bees and flies.

Sweet autumn clematis is very florific with many flowers (L) opening all at once (C). Each star-shaped flower has four white sepals and many stamens (R).

The flowers are followed by plumose seed heads.
Photo by Mark Dwyer, Rotary Botanical Gardens.

The flowers are followed by silvery plume-like seed heads typical of the genus (the dry fruits are a flattened achene each with a silky-plumose tail) which are dispersed by wind. The mass of fluffy seed heads can be quite ornamental. This plant can self-seed prolifically and the wind can blow the seeds great distances to potentially invade natural areas, so is considered invasive in many places. In colder climates (zones 4 and 5) it does not produce as many volunteers as in warmer locations. To prevent any seeding, cut the entire plant back to about three feet as soon as the flowers fade.

Plant sweet autumn clematis where it can climb a structure or cover open ground.

Plant sweet autumn clematis where it can climb up a structure – such as a fence or pergola – or ramble over an open area as a ground cover. It is far too rambunctious for a normal trellis. With its dense foliage and rampant growth habit it can quickly cover a chain link fence, arbor, or other structure to create a seasonal screen or cover eyesores such as old stumps or obscure an unsightly building or wall. Without support it forms a dense tangle of vines that will choke out other vegetation. Although it could be allowed to grow through large shrubs care would have to be taken to make sure it’s abundant growth doesn’t completely cover the other plant. Because of its pleasant vanilla-like sweet fragrance, try to situate it where the scented flowers can be appreciated.

Grow sweet autumn clematis in full sun to part shade in well-drained soil. Although it tolerates shade, it will bloom better in full sun. This species blooms on new growth, so it can be pruned hard in fall after flowering or in early spring to keep its rampant growth somewhat in check. Each stem can be cut back to a few strong buds a foot or two off the ground in late winter or early spring. Like all clematis, it likes “cool feet,” so the soil at its base should be mulched or shaded other plants. Fertilize in spring with a low-nitrogen fertilizer and keep evenly moist throughout the growing season. This plant has few insect or disease problems and is not favored by deer. This vine is not affected by juglone, so can be grown near black walnut trees. It is readily propagated from seed sown outdoors in the fall, softwood cuttings taken in spring, or semi-ripe cuttings taken in early summer. It may-grown take up to five years before seed-grown plants bloom.

– Susan Mahr, University of Wisconsin – Madison


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29 comments

  1. It’s beautiful. Sad that it’s invasive, but good to know.

  2. We have this flower growing at Rotary Park! It is BEAUTIFUL!! It can become invasive, so care must be taken to prevent unwanted spread by pruning it after flowering. It blooms in the fall and is nicely displayed by growing it on a fence or pergola. It is very fragrant, with a vanilla-like scent.

  3. My Sweet Autumn Clematis is getting white spots on the leaves, but leaves don’t seem to be dying or falling off. What can this be?

  4. I have had an autumn clamidas for the past five years and it is always gorgeous. However this year, mid June it looks dead, no growth. I have never prunned it. Should I cut back the dead vines and leaves 3 feet of the base?? Or is it too late? Any suggestions would be helpful

    • I had same thing happen to my vine. I planted it next to honeysuckle- they were both doing great and now sweet autumn looks sad!

    • This is not uncommon with sweet autumn. The new growth and flower buds are requiring a lot of nutrients, so the base of the plant can look “woody” with the leaves dying away.

  5. Good to learn all the characteristics of Sweet Autumn Clematis as well as Virginiana. I was trying to find out which Clematis was growing in my pots that I didn’t plant. I knew it was a Clematis by it’s twining and leaf characteristics but the sawtooth type edge had me wondering since none of my other Clematis have that. Good to know it’s the better one to grow since I have a terniflora that is growing rampant over my lower deck and climbing up the lattice to the upper deck. Last year I cut it down several times but it grew up again. Lovely flowers in the Fall though. This year the main stem is large and woodier and growing like crazy. It’s behind a large Camellia that keeps its roots shaded but it grows into the sun. I think I’m going to have to remove it and just grow the Virginiana in a well maintained pot since it has also self-seeded in several areas. I don’t want to upset the eco-system in this part of SC by allowing either to invade the area. I also have several other Clematis that have self-sown and I’ve transplanted but they grow nicely up trellises and there’s only a few at this time. Thank you for this article. It’s really helped me understand how to deal with these plants.

  6. We planted a sweet autumn clematis a few years ago along a fence line that is mostly shade so perhaps we will move it to a sunny location to see if it blooms.

  7. This is an interesting article. I thought it especially interesting because of the the type of plants being sold. You need to watch out for the leaves to make sure which type of plant you are getting. The smooth leaves versus the the native version C. virginiana being serrated. Keep your eyes peeled!

  8. I loved and grew this vine not knowing it is potentially invasive. In its second year it zoomed up a 4 X 4 post to my second story deck, and graced the railing with gorgeous sweet blossoms. I only cut off the topmost part of the plant in the late fall. In a few years I figured out that keeping this vine in check was lots of work so I replaced it with a ring of Ivory Silk tree lilacs that grew to 20 feet and gave the deck privacy and a little shade. For other gardeners I would recommend Virgins Bower because it is native, less invasive, and suggest they grow it in a place they can easily reach with lopping shears!

  9. I planted this a year ago. It did not return this year, so I planted another one. Perhaps I cut it too close to the ground? I will cut this one back to 2-3 feet providing it survives the winter.
    A friend has several Black Walnut trees. Good to know she could plant this on her property.

  10. Wisconsin Gardeners on facebook just had a a discussion on Sweet Autumn Clematis. I love the great news about a native alternative. It is a beautiful plant. I always wanted something to climb up some dead willow tree branches. It seems to be a good alternative. I live on a lake though so drainage may be an issue. Still I would like to give a try to find the native species also like to know another plant that isn’t affected by jungalone (Black Walnut trees) – a useful piece of information.

  11. I was discouraged from buying it st a local garden center. I bought a substitute which I do not remember but it did not make it. We do have a prolific one outside a gazebo at Free Spirit Riders where I do my MGV work. Another plant is growing nearby on a pergola which was not planted but must have self seeded. I noticed it is growing into a nearby shrub. Will have to cut it back!

  12. I did not realize they could be grown from cuttings. They are interesting in the winter with Christmas lights.

  13. c. terniflora can grow up to 30 ft. Not on the invasive list in Wisconsin but should be watched.

  14. I have a trellis I would like to plant something on that will climb. I was hoping this clematis might work but the trellis is in shade and probably would be consumed by this plant.

  15. Definitely not for the faint of heart. This aggressive woody vine in the buttercup family can and most likely will get away from the unattending eye and quickly become a nuisance. Having said this C. maximowicziana etc. does have a place in landscape designs. For example, in a past vegetable garden trellis was used to support the vines which were positioned to provide shade from late afternoon sun allowing extended growing season for leafy greens. Being in the garden it was rather easy to keep the vines pruned and cut back after the flower. As is always the case appropriate forethought avoids future heartache.

  16. I have learned something important to me about the sweet autumn Clematis – that if I trim it back to 3 ft. after flowers fade- but before seedpods form that should prevent it from being invasive so that it now works for my location to put it by a decorative fence near my house. so happy to have found this article

  17. Even though this plant is not yet considered invasive in Wisconsin, I would not plant it when there are alternatives that can be just a pretty. History has shown that a plant (or beetle) might not start out invasive but after a year or two, it’s status changes and then we are faced with the problem of how to control. I don’t feel it will be long before it is marked as invasive, given that it seeds prolifically and is dispersed on the wind. Did not realize the identifying leaf edges which will help separate it from the native species.

  18. I just bought this last year at one of my favorite garden shops. The shop sells mostly hostas, but also a few other shady plants. The owner had one planted and I, of course, had to know about it. “This grows in the shade?” I asked. His reply, “most anything will grow in the shade.” Not in complete agreement with him on that, however I knew I had the perfect spot for it, so I bought one. It has done well for me, glad I bought it!

  19. This is a vine plant, which can grow to 30 ft. long. In some states it is considered invasive, but not in Wisconsin at this time. It is a beautiful flowering plant with white star-shaped flowers which cover the foliage, making it very showy! It is hardy in Zones 4-9 and blooms in the fall. To avoid the dropping of seeds and creating the opportunity to become invasive, it can be trimmed back to 3 ft. tall right after the flowers fade, and before the seedpods form. I would like to try growing this, or its less invasive substitute, the climbing hydrangea, another beautiful white flowered plant.

  20. Sweet autumn clematis is a deciduous perenial that is hardy to zone 4-9. I did not know that it is considered an invasive species in the East and Midwest. It is not a regulated plant in Wisconsin on the DNR NR-40 list but should be used with caution. Sweet autumn clematis is very florific with many flowers opening all at once. To prevent any seeding cut the entire plant back to about three feet as soon as the flowers fade. This species blooms on new growth so it can be pruned hard in fall after flowering or in early spring to keep its rampant growth somewhat in check.

  21. The Sweet Autumn Clematis has a pretty flower. I like that it is prolific and that it could be used as a ground cover. I personally have not had much success with other Clematis in the past in zone 4.

  22. I am glad to learn it is useful to cover a fence and not just a trellis

  23. I learned that the Sweet Autumn Clematis can be invasive although less likely in cold climates. Two plants which could be substituted are Climbing hydrangea or Virgin’s Bower.

  24. I have always wanted to plant sweet autumn Clematis but thought it was invasive. As we are zone 3 or 4, after reading this article I’ve decided to give it a shot, since I’ve learned it’s not considered invasive in Wisconsin and other cooler areas.

  25. Given the invasiveness of this variety, it should be listed “avoid this at all costs!” I can just see planting it and in 3-4 years, cursing it. No thanks…

  26. Given what I read, it is a plant I will avoid. I found it interesting that it should be cut down to 3 feet after blooming to keep it from spreading.

  27. This vine is a favorite, but I can’t seem to grow it so now I will try a different spot with more sun and drainage.

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