Clematis is a versatile vining plant that comes in many sizes and colors. Monty Don, the British gardening personality, says, “Everyone loves clematis. To dislike clematis as a matter of principle would take a degree of perversity of the same order as disliking grass, trees or coffee ice cream. If you have a wall or fence, a decent-sized container or a patch of border, then you have room for at least one. In general, they are easy to grow, generous in flower and a cheerful addition to the scheme of things.”
Unlike twining vines that wrap themselves around a vertical support, clematis has delicate tendrils that need something smaller (3/4” or less in diameter) to wrap around. A piece of string or fishing line attached to the larger support is ideal. On the ‘Jackmanii’ cultivar we have growing outside our screened porch I keep last year’s main stem intact and that serves as the support for this year’s growth. The stem is attached to the side of the house with string and a few teacup hooks. The new growth each spring comes from the ground up, scrambling right up last year’s stem.
Clematis tendrils or petioles can wrap around other plants too. One offshoot of our ‘Jackmanii’ has found its way onto a shrub that finished blooming in early May. I trained the clematis in a deliberate way and now it almost looks like the shrub is in bloom again, but this time with bright purple flowers.
There’s a saying about clematis that they like ‘cool feet and hot heads.’ This means that their roots like to be kept in the shade and mulched to keep them cool, while the flowering part likes a lot of sun (at least 6 hours a day). If you grow a smaller clematis (under 10’ tall) in a container, pair it with shallow-rooted plants such as annuals to protect the roots. Be sure your container has good drainage. Avoid plastic or metal as they get hot.
There are many larger clematis that grow 20’ – 30’ tall. Flower sizes range from small (1 – 1 ½”) to large (6”) with sizes in between. Bloom times can be throughout the season, from spring through fall.
Not all clematis need full sun. I am looking for a clematis that is happy in part shade. Horticulturist Robin Zitter, in Sharon, CT, suggests Clematis virginiana, which is a native species and has a profusion of small white flowers late in the season. Don’t confuse it with Sweet Autumn clematis (C. terniflora), which has been listed as an invasive in our region. If you’re not sure which you have, check the leaves. C. Virginiana has toothed leaf edges and the invasive one has smooth leaf edges.
For a showier flower in part shade, Robin recommends a cultivar ‘Perle d’Azure’, which grows to about 10-12 feet and has a flower size of 5” across. It blooms from midsummer to early fall and gets cut back almost to the ground in early spring just before growth begins.
Pruning methods vary with different varieties of clematis. Some can be cut back to 1 foot from the ground and others like a light pruning or don’t need any pruning. Check the cultural recommendations for the one you choose. Brushwood Nursery, a mail order specialist in clematis, offers instructions on the various methods of pruning and labels each plant with the recommended method for that plant.
Robin has some favorite clematis species and cultivars and they include Clematis ‘Betty Corning’, C. ‘Etoile Violette’, C. ‘Huldine’, C. tangutica and C. ‘Rooguchi.’ She suggests these sources for purchasing: Oliver’s Nursery in Fairfield, CT and Brushwood Nursery.
Pronunciations of the word clematis are varied like the species itself. England’s Monty Don accepts several pronunciations, so if you say it one way and someone else says it differently, no worries! I say it with the accent on the first syllable.
Dorian Winslow is the owner of Womanswork, Pawling NY, (Womanswork.com). Email your gardening questions and comments to DWinslow@Womanswork.com