Clematis are deciduous, perennial, flowering woody vines. They are excellent climbers and extremely attractive on lamp posts, trellises, walls and fences. Their rich colors and varied bloom times can provide masses of color from spring to late fall. Clematis attract hummingbirds and are deer and rabbit resistant. There are over 250 different varieties of clematis. Their flower color, size, style and bloom time depend on variety.
Planting: When choosing a location for clematis, remember that the vine will need to be supported and it requires at least 5-6 hours of direct sunlight a day. Clematis prefer to have their foliage in the sun but their roots in the shade.
They like light, loamy, well-dug, rich, alkaline soil. Dig a hole about 5 inches wider and deeper than the plant’s container. Cover the bottom with rich compost or well rotted manure. Add enough topsoil mixed with a handful of bonemeal to cover the compost. Carefully remove the clematis from the pot and gently loosen the roots. Place the clematis in the hole so that the root ball is at least 2” below soil level.
The stem of the newly planted clematis should be very carefully secured to a support to avoid damage to the stem. Water deeply. Apply mulch around the base of the plant to keep the roots cool. Try using a ground cover or plants at the base of the clematis to provide shade for the roots. Clematis need regular watering to keep the soil moist (but not wet).
Pruning : “To prune or not to prune” is a tricky question with clematis. Some varieties bloom on old (last year’s) wood and the buds for this year grew last year. If pruned, the clematis will not bloom that year. Some clematis bloom on new wood and, therefore, do not have blooms yet. These can be pruned without losing flowers for that year. Pruning can be beneficial because it removes dead wood, controls the growth of the plant and keeps the plant lush and healthy. That said, incorrect pruning will not harm clematis. It will only delay flowering for a year.
Clematis Pruning Groups
Young clematis need a special first year pruning. Young plants should be pruned back
to a height of 18 to 24 inches regardless of itspruning code. This encourages good strong root growth, branching and the development of multiple stems. The roots and stems need to develop proportionately for proper growth and stability.
Group 1 - None - Flowers on last year’s stems. Only remove dead, weak or damaged stems.
Group 2 - Moderate - Flowers on last year’s stems. Prune in April or early May. Remove dead and weak stems. Trim just enough to keep it under control.
Group 3 - Hard - This group flowers on new growth each year. In late April or early May, remove old growth to about 12-18” above the ground, giving the plant a fresh start each year.
Possible problems: Clematis Wilt is the sudden collapse of plants just about to bloom. This due to a fungus and there is no cure. Remove wilted shoots and place in the trash, not in the compost pile. Clematis Wilt usually only affects young, thin stemmed plants. Most recover after being cut back. Powdery Mildew is also a fungus brought on by hot, humid weather. It looks unattractive but will not harm your plant. If you wish, routinely apply a fungicide even before you spot any Powdery Mildew as a preventative. Alternate a systemic drench with a contact product (neem oil, hort oil, Serenade). Mice and rabbits like to eat tender shoots at ground level. Use a wire mesh to protect them.