Merseyside,
United Kingdom 
i have a large clemetis which has big purple flowers on it at the moment it is still flowering but some of the vines and leaves look brown and dry should i cut it back ?
24 Oct, 2010
No. No Clematis should be cut back at this time of year. If it's in flower now, it's likely to be a group 3 type, which you should cut back hard in early spring when you can see the new buds appearing on the stems. Cut it back to the first or second pair of healthy buds.
24 Oct, 2010