Deciduous, Evergreen, Perennials, Vines
Of the more than 200 clematis species, most are deciduous vines; exceptions include the useful evergreen vine C. armandii, as well as some interesting upright herbaceous types.
Attractive blooms come in a wide variety of shapes; they may resemble bells, stars, tulips, saucers, urns—even miniature lanterns. Each flower consists of a central brush of stamens surrounded by petallike segments called sepals. Range of flower colors is wide, from pastel pinks to crimson red; periwinkle blue through soft lavender shades, rich magenta, and dark purple; and pure white through creamy tones and even golden yellow. Unless otherwise specified, blooms are 4–6 in. across. Float cut flowers in a bowl of water to make a choice indoor display. Burn cut ends of stems with a match to make flowers last longer. The blossoms of the large-flowered hybrids and a few species are followed by fluffy clusters of seed heads, also useful for flower arrangements.
Leaves vary from pale to dark green, usually divided into leaflets. Leafstalks twist and curl to hold plant to its support.
Deciduous vine, native to Europe and Asia. Grows to 6–8 ft., with lacy, soft green foliage. Early-spring blooms are nodding and bell-shaped, with four pointed sepals in white, pink, periwinkle blue, or purple, depending on the variety. An inner skirt of stamens is creamy white in most varieties. Blooms are followed by decorative seed heads. Plants are extremely cold hardy.
‘Constance’ has reddish pink flowers; ‘Pamela Jackman’ has blue flowers. ‘Ruby’ grows to 8 ft. with lacy, soft green foliage. Early spring blooms are nodding and bell-shaped, with four pointed sepals in rosy pink.
From China. Fast-growing vine to 15–20 ft. Leathery leaves are divided into three glossy, dark green leaflets to 6 in. long; they droop downward, creating a strongly textured look. Creamy white, vanilla-scented, saucer-shaped flowers, 1 1/2–2 in. across, are borne in clusters in early to midspring.
Leaves burn badly at the tips in areas where the soil or water contains excess salts. Best planted in a sunny, sheltered spot (out of harsh winds) with adequate support, such as a sturdy fence. Slow to start but races once established. Makes a great privacy screen if not allowed to become bare at the base.
These deciduous vines grow 6–10 ft. tall, unless otherwise noted. Flowers of most are saucer shaped and 6–8 in. across. Although there are hundreds of large-flowered hybrids in commerce, local nurseries usually offer only a limited selection of the old favorites and perhaps some of the newer, branded varieties sold as Signature, Patio, and Garland clematis. Mail-order catalogs are the best source for collectors seeking the new and different.
Native to Europe and Asia. Nonclimbing growth to 2–3 ft. or taller and about 2 ft. wide, with dark green, undivided 2–4-in.-long leaves. Nodding, sometimes fragrant, bell-shaped blue flowers, 1 1/2–2 in. wide, appear in summer. Useful as a border plant because of its diminutive size.
Native to the Himalayas. Vigorous grower to 20 ft. or more, with massive display of 2–2 1/2 in.-wide, anemone-like flowers from late spring to early summer; blooms in shades of pink. Give it plenty of room to roam; prune as for spring-blooming types.
Vigorous growth to 25 ft., with pale pink 2–2 1/2 -in. flowers and new foliage that is rich bronze, maturing to bronzy green.
The plant is semievergreen in milder areas. Native to China, Korea, and Japan. Very fast growing to 20 ft., with dark green leaves consisting of three to five oval leaflets. Produces masses of fragrant, creamy white flowers in late summer to fall. Can reseed. Plant in a warm, sunny location. Makes a good privacy screen or arbor cover. Often confused with C. paniculata, a similar species from New Zealand.
Deciduous vine, native to Texas. Fast growth to 6–10 ft., with blue-green leaves divided into three to five heart-shaped leaflets. Tulip-shaped scarlet flowers, 2–3 in. across, are produced in abundance from early summer until late fall. Use on posts or a tall trellis in a location with full sun and good air circulation to prevent powdery mildew.
Crosses with large-flowered hybrids have produced eye-catching varieties such as the vivid pink ‘Duchess of Albany’, crimson ‘Gravetye Beauty’, and rich pink ‘Princess Diana’.
From southern Europe and western Asia. Grows to 8–10 ft., with medium green leaves comprising five to seven small leaflets. Open, bell-shaped flowers are 1 1/2–4 in. wide and come in a range of colors, depending on the variety. Provides an outstanding display of blooms in summer and fall. Very versatile; good in combination with large-flowered hybrid types. This is one of the easiest clematis to grow; very tolerant of heat and poor soil.How to choose and grow clematis
Choosing a site. When deciding where to plant your clematis, remember that most types need 5–6 hours of sunlight to produce the greatest number of blooms. Site vining types next to an obelisk, trellis, fence, or arbor to give stems support for twining; or plant near the base of a shallow-rooted shrub or tree and let the vine scramble up into it. You can disregard the advice to plant clematis “with their feet in the shade and their head in the sun”—provided your plants are kept properly mulched and watered. To reduce competition for nutrients and moisture, make sure any closely neighboring plants are not too vigorous; shallow-rooted annuals and delicate groundcovers are good choices.
Planting. Dig a large hole, up to 2 ft. wide and deep, and plant in rich, loose, fast-draining soil; add generous quantities of organic matter. Add lime only if soil tests indicate a calcium deficiency. For large-flowered hybrids, as well as species such as C. crispa, C. integrifolia, C. pitcheri, C. terniflora, C. texensis, and C. viticella, plant with the crown (the point where the stems emerge from the soil in the nursery container) 3–5 in. below ground level. Deep planting ensures disease- or cold-damaged plants will resprout. Others can be planted with their crowns at ground level. Stems are easily broken, so plant carefully and protect with wire netting if near a path or where pets or children might brush by and snap them off at the base. Apply a 2–3-in.-thick layer of mulch around (but not touching) the stems to keep the roots cool.
In desert areas plant where there is protection from afternoon sun and strong winds. If you’re planting a deciduous clematis, cut stems back to 6–12 in. from the ground or to two or three pairs of growth buds, whichever is lower. Late in the following dormant season, cut the plant back to two or three pairs of buds; train shoots emerging that second spring. Don’t prune evergreen vines at first; just start training shoots onto their support.
Plant care. Clematis need regular watering and a steady supply of nutrients. Don’t let them dry out, and apply a complete liquid fertilizer monthly during the growing season.
Pruning. The basic objective of pruning mature clematis vines is to get the greatest display of flowers on the shapeliest plant. Pruning is not complicated, and these are forgiving plants that will soon recover from any mistakes. The type of pruning you do depends on when your plants flower. If you don’t know which kind you have, watch them for a year to see when they bloom, then proceed accordingly. Do keep in mind that dormant stems of clematis can look dead. Spring-blooming clematis (which may actually bloom in late fall or winter in mild-winter areas) bloom on stems produced the previous year. After bloom has finished, thin out weak or tangled stems, remove any dead or damaged growth, and cut stems back to the first (topmost) pair of healthy leaf buds.
Summer- and fall-blooming clematis bloom at the ends of new stems that were produced in spring of the same year. These vines should be pruned when their leaf buds emerge—this can be any time from late fall to early spring depending on whether you live in a mild- or cold-winter climate. Cut all the stems back to 12–18 in. above ground level, making each cut just above a pair of healthy leaf buds.
Twice-flowering clematis bloom on the previous year’s stems in spring, then again on the current year’s shoots in summer and fall. In late fall or early spring, prune lightly to thin out excess shoots or untangle stems. After the early blooms fade, prune more heavily so that new shoots will develop for the second round of flowers.
Pests and diseases. Aphids, mealybugs, scale, and whiteflies occasionally affect clematis. Snails, slugs, and earwigs may require control. Powdery mildew can be a problem on some types. Stem rot is a potentially serious disease of clematis. This fungal infection causes browning and wilting of leaves along an entire stem (it is sometimes referred to as “wilt”). Infection begins at the base of the stem, near the soil line. Small stems are more likely to become infected, so buy the biggest plant possible, and try not to break new shoots when planting. To treat infected plants, cut off all diseased parts, then disinfect your shears with diluted household bleach or another broad-range disinfectant. Dispose of diseased stems in a sealed plastic bag to avoid spreading fungal spores. Infected plants will produce healthy new shoots.
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