By Margaret Page Culver, Master Gardener, Colorado State University Cooperative Extension, Denver County
Interest in things Elizabethan is high in the wake of the success of the movies Elizabeth and Shakespeare in Love.
Among those things is the woody vine clematis, known in England as virgin's bower in honor of the first Queen Elizabeth.
After the expansion of travel and botany beginning in her reign, new species broadened flower colors found in European clematis varieties. The "cool" clematis colors of purple, blue, pink and white were joined by "hotter" shades of red and yellow.
Flower shapes now range from large, 8-inch hybrids to dainty bells and the honey-suckle forms of the autumn clematis.
Clematis belongs to the Ranunculaceae family, as do the hellebores, delphiniums, peonies, and anemones.
Many varieties of clematis perform well in Colorado, and their cultivation is relatively simple if gardeners can meet initial location and soil requirements.
In Colorado's climate, spring planting generally is more successful than fall planting. Vines will do best in full sun but bloom poorly in more than a half-day of partial shade. A trellis or other support is needed to help vines withstand Colorado's windy periods.
Clematis does best in well-drained soil amended with organic matter such as compost at planting. The crown, the part of the plant where the stem and the roots meet, should be positioned about two inches below the soil. Keep plant roots moist but not wet; they will not survive in waterlogged areas. Keep roots cool by mulching plants up to, but not next to, the woody stem.
Pruning these vines can be a bit complicated. Woody-stemmed types, such as "Montanas", bloom early on old wood. Prune them after bloom to remove dead wood and to keep the vine growth constrained. Large-flowered "Henryii" and "Elsa Spaeth" hybrid types also should be pruned this way.
Other types that bloom on the current year's growth should be cut back in early spring to the first pair of healthy buds. These include "Jackmanii" and "Ernest Markham".
In harsh winters, vines may freeze to the ground. In the spring, cut the vines close to the ground. New vines will emerge later in the spring, but blooms will probably take another year to return.
May your home be surrounded by bowers of flowers.
Photographs courtesy of Judy Sedbrook.
For more information on clematis, see The International Clematis Society
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010