In article ,
says...

My Clematis plants are starting to wake up could someone explain as to
where they are to be pinched out ( I think thats what its called ) to
make them flower better as last year they were very drab...........





Assuming you have done nothing as yet then take a look at them if there
are obvious flower buds in the shoot tips then leave them alone until
after flowering, if you can see no flower buds at the ends of the shoots
they can be cut hard to the ground during winter (now is still just ok)
it is seldom worth pinching them out while in growth except maybe in pots
--
Charlie Pridham, Gardening in Cornwall
www.roselandhouse.co.uk
Holders of national collections of Clematis viticella cultivars and
Lapageria rosea