General Characteristics: Clematis may be planted and trained to cover walls, trellis, posts, fences, arbors or to cover rocky sites. It will need support. Prefers a rich, well-drained soil with a pH of 5.6-6.5. Clematis do best in neutral or slightly alkaline soils, but they are somewhat adaptable. If you have very acid soil, try to add some calcium when you plant. If you want to grow really good clematis you should incorporate a little lime in the planting holes. Roots should be planted in a cool moist environment, while the vine itself should be in the sun. Root area should be protected. They require 1" of water a week. Clematis 'Jackmanii' is possibly the best known Clematis in the world and is the best blooming Clematis in its family. 'Jackmanii' is the most popular large-flowered variety and it is very healthy and hardy.
Clematis Repeat Blooming: GROUP C: These are the late large-flowered cultivars and other clematis species. They flower in late June into August. These bloom on new wood from the current season so you don't need to maintain any old wood. They should be cut back to a living bud at about 24" from the ground in spring just as the buds swell. If you don't prune, the flowers will tend to be only up at the top of the plant and the bare stems will be unattractive below.