A beautiful clematis CraighB, I have found it to be quite slow growing, but mine is in heavy shade, it is very floriferous. I wouldn't pinch it out, you've already cut it hard back, that's all it needs - and lots of food.
Aaah - thank you CraighB for bringing this up - I have Pink Fantasy - good to learn what to do from other people's experience
Clematis aren't the same as annuals. Pinching out an annual will help it develop more flowering stems so that it does a better job for it's single growth season. Clematis are more like shrubs in the sense that you prune them to develop the mature plant. This also promotes new growth, but it's different from the growth produced by an annual as it's in order to create the eventual structure for flower buds to form. They are long term plants so you're building their future.
Hope that makes sense
Yes - I understand what you've said Fairygirl - thank you. So when do you actually start pruning a young plant - I think I understand about the groups - but are we not concernd then about promoting growth from the bottom of the plant? In other words, how long do you leave the leading shoot ...... if that's not a generalisation