Jackmanii Group clematis

'Jackmanii Superba' is probably one of the most popular large-flowered, late-flowering clematis. The rich dark purple flowers are like velvet, and make are a wonderful sight, clothing walls from mid- to late summer. As with all the late-flowering clematis, pruning is easy. Simply cut back the stems to a pair of strong buds 15-20cm (6-8in) above ground level before growth begins in early spring. This pruning technique makes late-flowering clematis useful for training into shrubs, trees and climbing roses as the clematis growth is removed each spring and so never becomes too much of a burden on its supporting plant.