clematis

I am not an expert on clematis, but I don`t think pinching out has any effect, usually just leave mine to scramble and try and tie in the off shhots to cover whatever it is growing over.

I pinch out with some Clematis it does increase the number of blooms and also means it does bloom later.

Clematis should be pruned every year to keep them from becoming straggly - if this is done, you shouldn't really need to pinch out to maintain bushyness, it just happens! Pruning time depends on what type of clematis you have (and thus what time of year it blooms). Now is not the time whatever type you have, I'm afriad.