This group contains some of the most vigorous clematis. When used to cover large areas, such as walls or fences, no pruning is required. If, however, space is limited some pruning may be necessary. If you do need to prune a Group 1 clematis this should be carried out as soon as flowering has finished. This allows the plant to produce some new growth which will supply the flowers for the following year.
This group contains the early and mid-season large flowered hybrids which usually begin flowering before the end of June. Although no regular pruning is required, you may wish to remove any dead tips from the stems. This will keep the plant looking tidy. In late February or early March, working down from the tips, follow each stem until you come to a pair of live buds. Remove the end of the stem by pruning just above this point.
This group contains all the late flowering species and hybrids. Although these varieties will flower if left unpruned, they will soon become bare at the base and flowers will be produced well above head-height. This is ideal when growing clematis into a tree, but for general use hard pruning is recommended. Each February, prune all stems back to approximately 30cm (12") from ground level, cutting just above an old leaf joint. New growth will soon appear, resulting in a plant whivh is green from top to bottom and with flowers at a more acceptable height.