By Gillyflowers
Wiltshire,
United Kingdom 
I have a dark red clematis (name unknown) that's still blooming but beginning to go over. Can I cut it back or should I leave it - can't remember Monty Don's rule!
19 Nov, 2012
Answers
The rule is, if it flowers late June/early July onwards, cut it by 15th February at the latest, down to about 8 to 10 inches or 2 buds. So midwinter onwards, after all the topgrowth as died back.
19 Nov, 2012
Thank you - I shall make a note for future reference.
20 Nov, 2012
Sorry, I don't remember which one it is and the name tag has long gone!
21 Nov, 2012
Previous question
if its flowering mid smmer on, then generally you prune in the spring as it flowers on new wood.
19 Nov, 2012