Clematis is by far one of the most popular summer-flowering vines because of its distinctive flowers, nice leaves, rather uniform growth habits, versatility and ease of care.
Clematis flowers come in a wide range of colors and sizes, from an inch in width to nine inches or more. Most varieties are deciduous, meaning they lose their leaves over winter. However, Armandi, Hendersons rubra and Little Joe (a small leafed variety), have evergreen foliage.
Clematis comes in shades of pink, rose, red, purple, lavender, blue and white. A few varieties have flowers with two colors or are striped. Although most varieties are single, a few are double.
USES IN THE LANDSCAPE
This versatile vine is most often grown on a trellis, arbor or along a fence. They are also used to cover old stumps or to grow up into trees. The vines are often used effectively to hang along the eaves of the house or similar locations. They can be grown in the ground or in containers.
A FEW POPULAR VARIETIES
Keep in mind, these are a few of my favorites. You'll probably find others you like even more. Because there are hundreds of other varieties, some of which are probably nicer then those mentioned.
Clematis prefers a bright, sunny location but will grow in partial sun and shade. After making that statement, I must tell you the most beautiful 'Nellie Moser' clematis I have ever seen was grown against a house with a northern exposure. Although the vines like plenty of sun, the roots should be shaded and kept cool in order for the vines to grow at their best. This can be accomplished by planting annuals, perennials or small shrubs at the base of the vine.
HOW TO PLANT
At planting time, mix generous amounts of organic humus in the form of compost or processed manure into the planting soil. A good rule to observe is about 1/3 organic humus and 2/3 of your existing soil. Prepare an extra deep planting hole because clematis has an extensive root system. Incidentally, this is one plant (vine) that can be planted deeply.
LIME THE SOIL
If your soil tends to be acid, add about one cup of dolomite lime into the planting soil. Clematis needs a sweet soil in which to grow and will benefit from a light application of lime in future years, in areas where the soil is acid.
Clematis vines are rapid growing, flower prolifically and will benefit from feeding twice yearly. The first feeding can be done in late winter and the second in late spring. Use a rose-type fertilizer following label instructions and water thoroughly after application.
If the lower foliage begins to turn yellow or brown this often indicates the need for magnesium, so one should make an application of Epsom Salts (Sulfate of Magnesium) at the base of the plant, on the soil. Apply according to label instructions (horticultural use) and about April 15th is an ideal time. However, if lower leaves begin to turn off color later in the season, make the application of Magnesium Sulfate when you notice it.
The most misunderstood thing about clematis is when to and how to prune. If the vines are allowed to go year after year without pruning, the lower portions develops woody stems and becomes unattractive, with all the flowers at the top of the vine. Pruning them back encourages bushy growth and more flowers throughout the entire vine.
So here are some pruning suggestions: The most popular large summer flowering clematis is pruned during the winter dormant season in February or March. (In cold climates a little later, but before the new growth starts.) Spring blooming varieties such as Montana rubens are pruned immediately after they have finished flowering.
Those pruned in February or March can be cut back to about waist height. Spring flowering varieties that are pruned when they finish flowering, should only be thinned to encourage side branching and the development of new growth.
YOU SHOULD KNOW
When first planted, the vines may be a bit slow to show growth or flowers. This is due to the plant devoting its growth to a new root system. Once established, the plant will respond with prolific top growth and flowers.
If a clematis vine dies back, this usually means the plant has been over-watered or that the root area is not cool enough for the sensitive root system. However, it can also be a sign of a blight that will sometimes, quickly kills the top growth. If this appears to be the case, apply a fungicide on the soil and vine, and keep your fingers crossed, as the vine may recover.