grandadterry needs help

grandadterry

My Clematis, Montana has been in for about 16yrs with very little pruning and it has got about 12inches of deadwood and only the top 2inches of green. Can I cut it back? if so how far?. Your help is sorely needed. G/Dad

AnniD

I cut mine back to around a foot in height earlier this summer and it's heading back to the top of the wall again 

Lyn

I cut our huge one down almost to the ground, if you do it now you won’t get any flowers next year as Montana’s bloom on last year’s wood.  But it’s worth that I think. 
Either that or you can wait till it’s flowered then prune straight away then it will put on growth and flower the  following year.