Answer: There are numerous types of clematis and the suggested pruning depends on which specific variety you have. Generally speaking, the early spring bloomer blooms on old wood. It should be cut back immediately after it blooms if needed for shaping purposes but does not require pruning.
The mid summer bloomer should be cut back hard in early spring, leaving about 12 inches. Unfortunately, there are two groups of summer bloomers, so whether you should prune yours every spring for best performance or only prune it if it needs to be brought back to size is an open question.
It is possible to start clematis from summer cuttings but it is fairly tricky. That's why most gardeners purchase professionally propagated plants.
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