HEN MOST people think lavender flowers that sometimes have wife of publisher Abner Doubleday— of , they imagine a pale margin; C. hirsutissima, a deep took much notice of our native . W eye-catching hybrids such mauve- to violet-flowered native of the The exception to this neglect was scarlet as wine-red ‘Ernest Markham’, laven- Northwest; and C. texensis, a scarlet to or Texas clematis (C. texensis). As the only der-blue ‘Ramona’ with its rounded se- magenta native of Texas. clematis with red flowers, scarlet clematis pals, or double ‘Duchess of Edinburgh’ was cherished by breeders, who employed with flowers like crumpled damask SOME FAMILY HISTORY it to bestow its singular hue—as well as napkins. Or they may know and grow Clematis are members of the buttercup or vigorous growth, long season of bloom, smaller-flowered, mass-blooming spe- crowsfoot family (). The and tolerance of heat and humidity—on cies such as snowy name is derived from the Greek numerous hybrids and selections. and golden C. tangutica. word klema, which means a climbing or But gardeners who are interested in in- branching . There are more than 250 TEXENSIS AND THE LEATHER FLOWERS tegrating more North American natives in known species, most originating in the The undisputed star of North American their landscapes may be surprised to find temperate regions of both hemispheres, clematis, scarlet clematis (Zones 5–9, great diversity among our own less publi- and in excess of 2,500 selections. 9–1) is native to Texas and surrounding cized clematis. “Most people come into the

Our bashful native clematis don’t get the attention of the flashy-flowered hybrids, but they are elegant enough to deserve a space in the garden.

BY CAROL HOWE

genus through the large-flowered hybrids,” says Linda Beutler, author of with Clematis and curator of the Rogerson Clematis Collection in West Linn, Ore- gon. “These have been made diffi- cult to grow by contradictory pruning ad- vice, and these are the only clematis prone to wilt disease. The native clematis, on the other hand, have a great deal more charm and subtlety. Natives are immune to wilt disease. Also, native clematis are super com- panion plants, wandering through Hybrid clematis that have been developed using scarlet clematis include bicolor pink- and over dwarf conifers without being so flowered ‘Duchess of Albany’, above, and red-sepaled ‘Gravetye Beauty’, opposite. with massive or heavy as to disturb their host. Clematis Some North American species, like Clem- The colorful “” of clematis are states. Its nodding, urn-shaped flowers, atis crispa, C. texensis, and C. viorna, have a actually that surround a cluster of which arise from new wood between very long period of bloom.” usually contrasting-colored . Al- July and October, can range from scarlet Native clematis can be found in most though clematis can have between four to a dull reddish purple. The flowers regions of North America, from north- and eight sepals, most of the North Amer- narrow at the point where the thick se- American Roots west Canada to Baja California and from ican native species have four. pals open and curl backwards, revealing Florida to Nova Scotia, although the ma- Clematis became popular in Europe a glimpse of a pink to yellow interior. jority of species are clustered in the East in the early 1800s, but on this side of the Scarlet clematis thrives in a site in full and Northwest. Among the best known Atlantic, only naturalists such as Neltje sun (with roots in shade, if possible) and

SUSANROTH A. LYNNEHARRISON are C. crispa, a southeastern native with Blanchan—a late 19th-century writer and tolerates heat quite well.

22 the American Gardener July / August 2014 23 In clematis circles, the species and its many hybrids are collectively described TIPS FOR GROWING CLEMATIS IN THE GARDEN as the Texensis group. Perhaps the most highly regarded of the selections is ‘Duch- LIGHT REQUIREMENTS AND SOIL near ground level each year while dormant. Western species ess of Albany’, prized for its prolific, bi- Select a site for your clematis where its roots will be protect- such as C. occidentalis var. grosseserrata and C. columbiana, color-pink flowers that bloom over a long ed from direct sun during the hottest part of the day in sum- on the other hand, bloom on old wood and should only be period, followed by decorative seedpods. mer, but the foliage will receive at least filtered sunlight. For thinned occasionally to stimulate new growth. Other notable are ‘Gravetye most native species, a slightly acidic to neutral soil is ideal. Beauty’ (red), ‘Etoile ’ (rosy pink), In general, clematis thrive in rich, loamy, free-draining soil, PROPAGATION and ‘Princess Diana’ (bicolor pink). so if your soil is heavy clay or too sandy, be sure to add Many nurseries sell potted clematis (see “Sources,” page 26), Related to C. texensis are several other mold, compost, or other well-rotted organic material to the but some of the native species may only be available as seed. North American clematis species featur- planting site. After planting, water the site thoroughly with a Clematis seeds germinate fairly rapidly if sown shortly af- ing four tough, thick sepals that are joined slow-running hose, then add an inch of light-colored mulch ter they ripen in early fall, but seeds that have been stored for to form nodding, urn-shaped blossoms around—but not touching—the ’s base to help keep the more than a few weeks may need several cycles of cold and with reflexed (upward curling) tips. The roots cool and deter weeds. heat to germinate. Clematis —technically achenes— thickness of the sepals led to several spe- When it comes to soil pH, says Linda Beutler, author of Gar- have a prominent hairy “tail” that should be removed before cies—including C. viorna, C. versicolor, dening with Clematis, “generally, the southeastern U.S. clem- seeds are sown, says Beutler. “For the Viorna group, the C. crispa, and C. addisonii—becoming atis species—those in the Viorna group—will adapt to a wider seeds are large and the seed coat (pericarp) is tough, so I known by the common name “leather range of garden conditions than our Northwest species do.” soak them for five days at room temperature and then peel flower.” Some taxonomists lump togeth- Clematis that do require neutral or alkaline soil—especial- off the pericarp before sowing,” she adds. er clematis with these characteristics as ly low-growing, herbaceous types such as Fremont’s leather Following the advice of seed germination guru Norman the Viorna group. Most are low-growing flower (C. fremontii) and whitehair leather flower (C. albico- Deno (author of Seed Germination Theory and Practice), with delicate flowers, ideal for place- ma) —are good choices for containers or troughs. “Something Susan Austin, owner of Completely Clematis in Ipswich, ment on a trellis in a partly shaded border slow-release like crushed oystershells does wonders for these Massachusetts, sows her native clematis seeds on moist or being allowed to cascade gracefully over plants in acidic soil areas,” Beutler adds. paper towels and places them inside resealable plastic bags. small nearby shrubs. These are then stored in the refrigerator, and checked weekly (Zones 4–9, 9–1), PRUNING for germination (or evidence of mold). Once the seeds start to sometimes called vase vine, is found in Different types of clematis have different pruning require- germinate, she carefully transfers them into individual pots gravelly soils from New York west to Il- ments. Scarlet clematis and the species in the leather flower and places them under grow lights. linois and south to Georgia and the Gulf group all bloom on new wood, and thus should be pruned to —David J. Ellis, Editor Coast. Its sepals are mostly reddish purple, but the tips—which may curl upward like elfin shoes—reveal a greenish or creamy bloom on their long stalks, the tips “It’s easy to grow, fragrant, with a long white interior when the flowers open curl back to reveal a downy interior. season of bloom, followed by boisterous in midsummer. It grows seven to nine Sometimes known as blue jasmine, seedheads that are easy to germinate if you feet tall on a trellis or with the support swamp leather vine, or curly clematis, C. want more. The charming flowers earn of nearby shrubs. The late garden writer crispa (Zones 5–9, 9–5) also has down- their ‘crispa’ chops by being as crenulated Christopher Lloyd compared the golden turned flowers, but with more delicate se- as a square-dance petticoat.” seedheads that form in late summer to pals than other “leather flowers.” The se- Swamp leather vine’s genes have been many-legged “tropical spiders.” pals—distinguished by ruffled edges and incorporated in a number of hybrids, in- (Zones 5–9, 9–1) is strongly reflexed tips that often curl back cluding the well regarded selection ‘Betty found from Kentucky and Tennessee west on themselves—are pale blue to lavender Corning’ (Zones 4–10, 9–4), which bears to Missouri, Oklahoma, and Arkansas. It with a lighter band on the interior midrib lavender to pale purple flowers. has small but numerous summer to early of each, forming a star around the central fall flowers on a seven- to 12-foot vine. Its cream-colored stamens. The blooms may FREE-CLIMBING CLEMATIS sepals are rosy pink on the outside, fading be few in number, but they reappear con- In sharp contrast to the low-growing, del- to almost white towards the tips. tinuously from May to September and icate leather flower group is woodbine (C. Addison’s clematis (C. addisonii, have a light fragrance. virginiana, Zones 4–9, 9–1), a vigorous Zones 5–8, 8–3), restricted in the wild to Swamp leather vine grows from six climber that can reach 20 feet. Look for limestone and dolomitic glades and banks to nine feet tall and is native from Penn- it trailing over plants and bushes in moist in western Virginia, is a bushy plant that sylvania west to Missouri and south to Woodbine is a vigorous climbing clematis woods or along stream banks from Nova reaches only one to three feet in height. Texas and Florida, where it is often found that has numerous white summer flowers Scotia to Georgia and west as far as Manito- Distinctive heart-shaped are borne growing in forests, along riverbanks, and and attractive seedheads in autumn. ba and Tennessee. Although it blooms from on almost nonexistent leaf stalks. Its leath- in marshy areas. Its stems usually die to July through September, woodbine is better ery sepals are deep reddish purple on the the ground in winter, and in the northern er of organic mulch. Linda Beutler lists known for its fall display of plumy silver seed- outside and creamy white inside. When “Leather flower” clematis species that have bell-shaped flowers composed of four thick, reflexed extent of its range, the crown of the plant C. crispa among her 10 favorite clematis. heads than for it unspectacular small creamy

the solitary early to midsummer flowers sepals include vase vine (Clematis viorna), top, and swamp leather vine (C. crispa), above. LYNNETOP: HARRISON. STRAUCH,JOSEPHG. BOTTOM: JR. BILLJOHNSON should be protected from frost with a lay- “What’s not to like?” she asks, rhetorically. white flowers. Known by several common

24 the American Gardener July / August 2014 25 The range of C. occidentalis overlaps Sources that of a related species (some sources list Alplains, Kiowa, CO. (303) 621-2247. it as a subspecies of C. occidentalis) called www.alplains.com. rock clematis (C. columbiana, Zones Brushwood Nursery, Athens, GA. (706) 4–7, 7–3), which has purple to blue, 389-0689.www.gardenvines.com. May-blooming flowers with translucent Completely Clematis Nursery, Ipswich, sepals that are even broader than those of MA. (978) 356-3197. its more eastern relative. Rock clematis is www.clematisnursery.com. found from British Columbia and Alber- Joy Creek Nursery, Scappoose, OR. ta south to Oregon and Colorado. (503) 543-7474. www.joycreek.com. Another western species, native to Shooting Star Nursery, Georgetown, meadows and high desert from Washing- KY. (866) 405-7979. ton and Oregon west to South Dakota and www.shootingstarnursery.com. south to New Mexico and Arizona, is hairy Woodlanders, Inc., Aiken, SC. (803) clematis (C. hirsutissima, Zones 4–7, 7–3). 648-7522. www.woodlanders.net. Also known as sugar bowls, its rounded, leathery, downturned flowers are formed of deep purple sepals that curl back at the very Resources tips to reveal creamy stamens within. Sugar Gardening With Clematis: Design and bowls rarely grows more than two feet tall, Cultivation by Linda Beutler. Timber and both its foliage and sepals are covered Press, Portland, OR, 2004. with fine silvery hairs. It can be grown in Guide to Growing and Propagating a sunny border with free-draining soil, a Wildflowers of the United States and rock garden, or a container. A botanical Canada by William Cullina. Hough- variety, C. hirsutissima var. scottii, differs ton Mifflin, Boston, MA, 2000. from the species in having bipinnate leaves, International Clematis Society, sepals that are a paler shade of lavender, and www.clematisinternational.com. growing up to a foot taller. MIDWEST CLEMATIS names—including old man’s beard, virgin’s In its native habitat in the Pacific Northwest, In the harsh climate of the Midwest prai- bower, and my personal favorite, devil’s rock clematis, above, grows in full sun on ries, certain native clematis tend to be more darning needles—it is sometimes confused limestone-based soil. Fremont’s leather herbaceous in habit. Fremont’s leather with non-native sweet autumn clematis (C. flower, right, native to alkaline sites in the flower (C. fremontii, Zones 4–7, 7–4), for terniflora), but the flowers lack fragrance. In lower Midwest and South, forms bushy clumps instance, grows only one to two feet tall, the eastern United States, woodbine grows to two feet tall and is a good option for troughs. forming dense clumps in sites where it is so vigorously and self-sows so readily that it happy. Native to Nebraska, Kansas, and can become a bit of a nuisance, especially in Missouri, its nodding flowers bloom in ear- small gardens, but it is less rambunctious in CLEMATIS IN THE WEST ly summer in shades from purple to white. the western part of its range. In addition to C. ligusticifolia and C. lasian- Fremont’s leather flower is endemic to sites Its western counterpart, usually called tha, there are several clematis from western underlain with limestone, so it does require virgin’s bower, is C. ligusticifolia (Zones 5–9, North America worth considering. One of neutral to slightly alkaline soil. ‘Betty Corning’, a hybrid whose parents include vase vine () and C. viticella, 9–4), native from western Canada south to the widest ranging native clematis is purple A more vinelike species, growing six to grows to six to 10 feet tall. From midsummer into fall, it bears hundreds of dainty, lightly California and Mexico and east to the Rock- clematis or bell rue (C. occidentalis, formerly 10 feet tall, is bluebill (C. pitcheri, Zones 4–9, fragrant, pale purple flowers with eye-catching white markings. ies. It grows to 20 feet tall or more, with clus- C. verticillaris, Zones 3–8, 8–3). Along with 9–4), native from Indiana south to Missis- ters of small white flowers in late spring and its two botanical varieties (described later), it sippi and west to Nebraska and Texas. It is woods, and even more exciting when you species.“I find native clematis much easier to decorative seedheads in autumn. encompasses a vast native range from British distinguished by five ribbed sepals that are realize a number of them are actually in grow and tougher than a lot of the hybrids,” Native exclusively to California and bor- Columbia to eastern Quebec, south to Wis- pale lavender or rose on the outside and ru- cultivation (for a list of nurseries that carry says Susan Austin, who runs Completely dering coastal Mexico, chaparral clematis consin and northeastern Iowa and east as far by red to purple inside. Creamy to greenish some of these species, see “Sources,” page Clematis nursery in Ipswich, Massachusetts. (C. lasiantha, Zones 5–8, 8–5) is another as West Virginia and New England. can reach two inches long but rarely open white stamens provide a lovely contrast to 26). Some are ideal for naturalizing a corner “I wish more people knew about them be- white-flowered option. It can grow up to The species, which inhabits the eastern fully. Its botanical varieties are C. occidentalis the sepals. Its large leaves are divided into of your garden. Others will look terrific in cause they are worthy garden plants.” m 20 feet tall, developing woody stems where part of the range, is a woody-stemmed six- var. dissecta, a three-foot climber with rosy seven to nine occasionally lobed leaflets. the border as late season adornments for a fully hardy. It bears showy flowers composed to 10-foot clamberer that thrives in forested pink to purple flowers, found in the Cascade small whose spring flowers are long Carol Howe is a freelance writer who re- of white sepals surmounted by pincushion areas with rocky, alkaline soil. It has broad, Mountains of Washington, and the indi- MAKING ROOM FOR NATIVE CLEMATIS gone. Still others can be trained up a small sides in Rockland, Maine. This article is a clusters of prominent yellow stamens in drooping, almost translucent, lavender to go-flowered C. occidentalis var. grosseserrata, These species are just a few of the many trellis or grown over an arbor. revised and updated version of one originally spring, and then offers a second flush of or- purple-blue, downy sepals. Arising singly found in Alaska, northwest Canada, and that are native to our continent. It’s fun to And finally, don’t be discouraged by any published in the May/June 1996 issue of The

namentation via its silky fall seedpods. from leaf axils or branch tips, the flowers south to Colorado. LYNNEJERRYBOTTOM: TOP: PAVIA. HARRISON. SUSANROTH A. discover these clematis on rambles in the reports about the finickiness of the native American Gardener.

26 the American Gardener July / August 2014 27