Can I prune back my clematis montana to within a couple feet or will I kill it.
By Motown
United Kingdom 
Montana has got lots of dead looking vines, flowers grow at tip which is in a tree and other side of pillar of wall. I would like to encourage flowers at garden level. Is this possible? would appreciate any advice, thanks.
20 Jul, 2009
Answers
I've got a different take on this from Fractal. I think, if its outgrown its allotted space, and isn't particularly attractive from your point of view, I'd cut it back, not to a couple of feet, but to six/eight feet from the root, BUT not till after its flowered in the Spring next year. I have done this once before - the plant survived and grew much better. You do risk it not coping with the pruning, but what the hell, you don't like the way it looks anyway - give it a chance and cut it back, if it recovers, fine, if it doesn't, well plant something else.
20 Jul, 2009
Unfortunately, at least from an aesthetic point of view, I think your plant sounds quite healthy. The "dead looking" stems/vines are just covered with stringy, flaky bark that sometimes hangs in long linear shreds. Quite normal.
Being a vigorous species, and the type it is, the answer is no, it will not appreciate being cut hard back. It may well shoot from the base or lower stems but this cannot be guaranteed.
Why not plant another type of Clematis or even a different climber at the base to cover the stems?
20 Jul, 2009