Answer: Some clematis are pruned very hard and some are pruned very little. So the answer really depends on what kind of clematis you have. But, as a rule, you can trim off any winter damaged or dead stems in late winter to early spring. If your clematis blooms in the spring on old growth, you can trim it back after it blooms if you need to control its size. If it tends to bloom on new growth in the summer, trim it back quite hard in late winter or early spring. Cut just above a pair of live buds.
If you have done no pruning yet and there are dead pieces of stem, go ahead and cut them off now. I would not prune live growth at this time of year. I hope this helps.
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