I have several clematis. At least one is climbing up a cedar tree and I am wondering whether it can harm the tree.
If you prune the clematis yearly, they cannot grow large and heavy enough to do any damage to the cedar boughs.
I have a Clematis ‘Prairie Traveller’s Joy’ which grows many many feet into my crabapple tree. I allow it go as high as possible. Each year I cut back anything that is in the branches so that it cannot do any damage the following year.