Clematis

Botanical/Latin
   Clematis

Pronunciation
   Klem-a-tis

Common Name
   Vase Vine

Hardiness zone range
   4

General Comments
Exceptional climbing plants with showy flowers that come in a wide variety of colors, types, and sizes, and may be followed by silken seed heads. They climb and clothe supports by means of twining leaf stalks that twist around any slender support available.

Light Preference
Sun to Partial shade

Culture & Care
They thrive in rich, fertile, loamy soils that have a PH level that is on the alkaline side of neutral (ph 7 is ideal). Soils should be well drained and have the capacity to retain moisture in dry weather, so it is well worth excavating a generous hole and incorporating extra compost or other human media at planting time. When placing next to walls, large trees, or anywhere that is likely to be drier, try to locate the planting hole out from the drier area and lean the young stems, including our specially designed wire trellis, towards the supports; this will help the young plants to get established and receive more moisture during the critical growth period of spring and early summer. Once they are established and attached to the supports, the trellis can be easily removed. Clematis respond well to good nutrition, so a light application with a well balanced fertilizer should be applied in early spring, and again in early summer, to help keep them lush and healthy. Many gardeners find the subject of pruning their Clematis to be confusing, so click on Pruning Clematis to find out when and how to prune your plants.

Uses
They are wonderful plants for placing on garden structures like pergolas, arbors, trellises, and archways. They are great for clothing and softening hard features like walls and fences, and are tremendously useful for placing on difficult places like cold, shady, north or east facing walls. In woodland or natural style gardens, they will scramble up the trunks of tall trees and evergreens to adorn the upper parts with grace and create color among the foliage. They are marvelous plants for containers, and can be used to cover screens and give valuable color and exotic interest to decks, patios, balconies, and roof gardens. Several cultivars can be planted together to complement each other and extend the period of flowering. They are excellent for cut flower arranging, too. They should be cut early in the morning or late in the evening and conditioned by standing in water overnight. The best stage to cut them is when the flowers have just opened, or, better still, when they are not quite fully out. They do not dry well, but the silken seed heads can be preserved by standing the stems in a mixture of one part glycerin and two parts water for a few days.

Background
The botanical name comes from a Greek word Klema that describes "a vine or climbing plant". There are about 300 different species; the ones that are best suited to our gardens hail from Europe, North Asia, North America, and one gorgeous species (Clematis paniculata) from New Zealand. During the last 150 years or so, many fine selections and hybrids have been introduced to make up the tremendous diversity or color, shapes, and forms that are available today. Robert Fortune (a Scottish plant collector, famous for introducing tea to India) brought Clematis lanuginose from China in 1850. It had larger flowers with overlapping tepals (botanical term for the flower petals), it flowered in succession from late spring through to autumn, and, when crossed with other species, formed the basis for the popular "Large-Flowered Hybrids". The most famous of these is Clematis x jackmanii. It was raised in 1860 on the English nursery of Jackman of Woking and was a cross between Clematis lanuginose and Clematis viticella. These hybrids became incredibly popular and many fine old cultivars are still grown today; unfortunately some are prone to the puzzling disease Clematis wilt. Recently, breeders have been using Clematis viticella and other species to develop cultivars with improved disease resistance. We grow several of these exciting cultivars, so explore the selection and see our list of favorites.

Pests & Diseases
Clematis have a reputation for being difficult to grow and susceptible to several pests and diseases. Fortunately, this is not the case. They are remarkably adaptable and able to grow and flourish under a wide variety of conditions, often with minimal care and attention. Like most plants, aphids, slugs, and mildew attack them occasionally. This is usually not serious, and with good cultural practice can be easily controlled. "Clematis wilt" (Ascochyta clematidina) is the most serious problem a gardener is likely to encounter. It is a fungal disease that attacks the slender stems of Large-Flowered Hybrids near soil level or within 3 feet of soil level. It interrupts the flow of sap, causing the upper parts of the plants to collapse and wilt. Typically, the symptoms appear during the peak of the growing season, just when the flower buds are about to open. It is distressing because it usually shows up without warning, and, within a few days, the wilted parts turn dark brown or black. The whole plant can be affected or, as usually happens, one or two stems get it first. If this is noticed, remove all infected material immediately, cutting the stems back to healthy material. Parts of the fungus may have spread further down the stems, so make sure to cut well beyond the point of infection (sometimes beneath soil level), remove and burn all plant debris. As an added precaution, it may be advisable to mix a solution of a systemic fungicide in a watering can and apply it around the base of the plant. Your Garden Splendor Center will be able to advise and help with the appropriate material. The plants usually recover by sending up new shoots (often from beneath soil level) and, with good culture, grow and prosper without any ill effects. Fortunately, this problem seems to be less prevalent than it once was. Modern nursery techniques ensure stronger, healthier plants, and plant pathology experts are understanding more about this disease all the time. The latest research suggests that the fungal spores are likely to be present on the soil surface before infection, and that they may get splashed up by rainfall or watering to enter through damaged tissue. Good culture and hygiene are, therefore, very important, since weak plants that are under stress are much more vulnerable than well-grown, healthy specimens. Preventing damage to the stems is also important, so consider keeping our specially designed trellis (that has the plant already trained on it) in place at planting time; this helps to protect them against damage from mowers, string trimmers, and twisting. In fact, we go to considerable lengths to make sure our plants are grown in sterile medium, that they are big, healthy plants, and shipped nursery fresh to give you the best possible defense against this problem.

Splendor Suggestions
Take a tip from experienced gardeners and put down a thick insulating layer of mulch to keep the roots cool during the growing season. In Victorian times, it was not unusual to see a large stone or rock placed over the roots to retain moisture and provide the same cooling conditions.

Companion Plants
The later flowering ones are absolutely superb when planted to grow up and flower with climbing roses. They both flower around the same time, the bold, exotic flowers complement the roses perfectly, and the color shades are easy to harmonize. They enjoy similar growing conditions, the twining clematis cling easily to the rose stems and training materials, and, a final bonus is that they can be pruned at the same time in spring. Strong growing ones like Clematis terniflora (paniculata) can be trained into large evergreen trees like Pines or Cedrus atlantica 'Glauca', while other vigorous ones like C. tangutica, 'General Sikorski', 'Polish Spirit', and 'Royal Velours' are great for training into smaller deciduous trees and evergreens, like Ilex (upright hollies), Cryptomeria 'Yoshino', or the elegant, golden Chamaecyparis 'Crippsi'. Most of the cultivars can be placed to grow over and through the wide selection of shrubs, so it is easy to devise combinations that suit individual tastes and combine the effects of foliage, flower, and form. As mentioned earlier, Clematis enjoy a cool, moist root run, so placing shallow rooting perennials at their base is a good way to shade the roots and complement the flowers. Our favorites include the silvery foliage of Artemisia and Dianthus (especially nice with the blue and purples), purple foliaged Heuchera (good with the whites), and spiky flowered Veronicas.