Posted: 04/03/2015 at 23:05
I don't pinch mine out either but group 2s and 3s get a good prune after winter, any time between now and the end of March for me depending on how long winter lasts. I cut them down to the ground or to a low pair of buds depending on which they are as some are more vigorous than others.
Then, as Bookertoo says, they need a very good feed as they are hungry, thirsty plants. I give mine slow release clematis food after pruning and a liquid feed of rose or tomato food as an instant tonic. A light scattering of wildlife friendly slug pellets helps too as the blighters love the new shoots.