[SafeHaven]

I'm in the process of working through the overgrown garden of our new house. It has extensive gardens with more plants than I know the name of, but I'll figure it out over time. One that I do recognise is a clematis, which looks ancient judging by the thick woody stems braided through the trellis tunnel thing its trained over (see photo - hopefully it hasn't loaded sideways again!!).

However, like everything else in the garden, it's gone a bit rampant, with growth sticking out and twirling around itself. There are no flowers on it.

I don't know much about clematis but I do know they have particular needs, and I wondered what would happen if I trimmed it back at this time of year? Would it hurt it? Should I just leave it? I have absolutely no idea what variety it is, nor do I know how to tell.

Can anyone advise?

[Fleecewife]

I'm not an expert.  I would wait until you have seen it flower before doing anything drastic, as when, or if, you cut it back depends on when it flowers and so which type it is.  Do it at the wrong time and you'll have no flowers next year.  In fact the advice to give your garden a full year before you attack it, is good advice, as so much is not visible at any one time. Go with the garden rather than imposing yourself on it too early on 
The easiest way to identify a clematis is by it's flowers, also somewhat by its growing habit.  You'll need a good identification book, and there do seem to be a lot of books about clematis out there.  There is also the RHS to consult once you have flowers.

[SafeHaven]

Thanks once again. Good advice. My instincts stopped me touching it without knowing what to do. I knew they were pretty fussy.