Posted: 24/06/2012 at 13:34
That's not quite right. If it produces small flowers in early to mid spring it's a group 1 and only needs pruning to keep it in bounds by trimmming off excess growth after flowering finishes or to renew vigour from the base by cutting one or two stems at teh base and then leaving them to wilt. They can be pulled out a couple of weeks later without doing too myuch damage to the rest.
Group 2s are the early, large flowered hybrids which flower on old wood in May and June. These need to be dead headed once flowering finishes and can also be pruned to keep within bounds or renew vigour as above. Both types should be fed as soon as they've been pruned and also in Feb/March when new growth appears. Group 2s often go on to produce a second flush of flowers in late summer and do this best if given the earlier prune and feed.
Group 3s flower in summer on new wood and should be pruned back either to the gorund or to the lowest pairs of buds in Feb/March depending on how cold you are. I sometimes have to leave mine till early April. again they should be fed once new growth shows. Group 3s can be large or small flowered.
The best way to check is to look at this site - http://www.clematis.hull.ac.uk/ - which allows you to search for info based on the clematis name, its description or a picture.