June 24, 1998

Front porches, downspouts, arbors, mailboxes, and fences are in full bloom right now. This is prime blooming time for the most popular flowering vine, Clematis. It seems everyone has their own way of pronouncing that word. Most people put the heavy emphasis on the second syllable. Some folks even pronounce the "a" as "eye". Plant nerds, however, put the accent on the first syllable, which is how it's shown in most botanical writings.

Regardless of how you say it, a clematis is a beautiful flowering vine worthy of a place in any landscape. Easy to grow once established, it brings forth a beautiful flush of color in early summer, and many varieties continue to flower to a lesser extent until frost.

The secret to making a clematis feel at home in your garden is to plant it where the roots will be cool and well drained and the top will be in the sunlight. A clematis does not like wet feet and will quickly give up the ghost if the soil remains wet. Planted in the cool shade of a small shrub or at the back of a flower border, the vine will grow up into the sunlight eager to climb the nearest support. A good layer of mulch will also keep the root zone cool.

Most clematis climb by twisting their stems and petioles (the stalks of the leaves) around the arbor or trellis. Supports made of small diameter material, such as wire or string, are easiest for the little tendrils to entwine. Large boards or pipes are difficult for the plant to grasp without a little help. Other plants and shrubs can be used as supports for clematis, too. I've seen beautiful combinations with old climbing roses.

The most common clematis in our area is Clematis x jackmanii, a profuse bloomer with velvety bluish-purple flowers. There's at least one on every block in town. Many other varieties are available in various shades of purple, blue, white, pink, and red. I have two favorites. Right now my Clematis viticella 'Etoile Violette' (French for "violet star") is covered with beautiful reddish-purple flowers with golden stamens. Unlike its common cousin, it will continue to flower until fall.

My other favorite is the sweet autumn clematis, Clematis ternifolia. In September, it will become a shower of dainty white stars. Each fragrant little one-inch flower has five narrow white petals (actually sepals). On cool September evenings the sweet light fragrance of this vine is a delight.

In early spring I cut back both of these vines to about 18 inches above the ground. By the end of May they completely cover their trellises. I treat Clematis x jackmanii the same way. If I didn't prune them back each spring, they would have bare legs and the flowers would appear only at the tops of the vines.

Pests and diseases are few but the most serious problem is clematis wilt. Thought to be a fungal disease, it causes the sudden wilting of all or part of the plant. If this malady strikes, remove all affected parts and destroy them, preferably by burning, not composting. Don't dig up or replace the plant. A well-established plant will come back. I have never seen this problem on small flowered varieties.