Marc Montefusco
Frederick County Master Gardener Program

Most clematis species are vines, and the most widely-grown vines are the so-called "large-flowered clematis" like Nelly Moser (pink), Duchess of Edinburgh (double white), and Jackmanii (dark purple). There are hundreds of varieties, and most require the same basic, if somewhat confusing, cultural conditions: partial to full sun exposure with protection for the roots, regular watering without waterlogging, heavy feeding, and soil that ranges from pH neutral to slightly acidic.

The most important of these requirements is "good light, protected roots." You can provide this by mulching the base of the plant heavily, or by placing low-growing companion plantings at the base of the plant, or by growing the plant through an upturned terra-cotta pot with its bottom knocked out. (This is more confusing to describe than it is to do. You just have to start with a small plant.)

Vining clematis also need a support: they're not wall-crawlers like ivies, but their tendrils will wrap around just about anything, including other parts of the plant. There are creeping and shrub-like clematis as well. Although my own experience with the coarse C. heracleifolia "Wyevale" has been less than stellar, I have seen clematis species used as effective ground covers and borders.

In our area, we can grow clematis that bloom early in spring (C. montana and its various hybrids and varieties also offer wonderful fragrances), in late spring and summer, and in late summer through fall. Many of the spring-blooming varieties provide restrained repeat bloom throughout the season.

Clematis usually take several years to become established, so it's important not to become discouraged too quickly. They are also fragile when handled: treat the plant gently until it is settled in. Once they're happy, the plants can become extremely vigorous, easily growing 8 to 10 feet tall. The fall-blooming clematis like the native Virgins Bower (C. virginiana), C. terniflora, and C. vitalba can cover small sheds and slow-moving animals with a mass of tiny, fragrant white flowers - in fact, they can become invasive (but still beautiful) weeds.

Most, however, are well-behaved, providing that they are properly pruned. When, how, and if you prune your clematis are critical but confusing questions. Some flower on the previous year's wood, some on current growth only. You must learn the pruning recommendations for the variety you are growing. Many specialty growers are happy to provide this information when they sell you the plant, and there are several excellent references available.

Still not hooked? Clematis are one of the few flowering plants that come in a complete range of colors, including true blues, reds, oranges, and yellows, not to mention some of the most pristine whites in the plant kingdom. And last but not least, their beauty does not end when the petals fall: the seed heads transform from tight whorls of glistening green to feathery spirals of brown and beige. No matter how you pronounce them, clematis are all that and more.

Read other articles on shrubs and vines