Clematis - prune hard back now?
I have a clematis that has just finished flowering. It was in situ from when I moved in to my house and it stayed put when the garden was "done", but its now looking a bit of a mess and needs some proper suport - previous occupants simply left the plant tied to the original two foot canes it came in and provided no additional support or trellis. It is only by sheer determination it has managed to reach the top of the fence by using a scraggy winter Jasmine that was next to it, but after that was removed its all collapsing on itself. OK to hard prune back now to allow me to install a trellis or should I wait will next Spring before new growth happens?