Clematis butchering

We've been trimming back wisteria & clematis before they really start growing. One clematis is very woody & dead-looking but new branches are growing. It looks very untidy even when in flower. We've ended up accidentally cutting a bit that had lots of new growth on... Can I butcher this? I've got another, identical one on the wall next to the rockery, which in some ways is worse as access is more tricky

 

You can butcher this and it will grow back but you will lose most of this year's flowers if you do it now. I'm assuming it's a Clematis montana which flowers in early May. However, the following year it will flower fine as long as you've given it a season to form new flowering stems.

 

Wisteria flowers in mid0-spring also, so assume the same rules apply to them. I'm less familiar with wisteria but I believe they sometimes have a late-summer flush of flowers so even if you prune now you might get those.

 

Thanks @Madahhlia & @ARMANDII

I'm pretty sure it flowers spring/summer. It has pale pink 5-petalled flowers that are about 2" across. Last year this particular clematis only flowered near the top, and off the growth that had been fed to the left of this photo through a couple of climbing roses. So mostly you could only see wood when you were on the patio, and the flowers were more visible from further away.

So... if I cut it all the way back, irrespective if I want flowers this year or not, I won't kill it? It's been neglected by the previous owners of our house; last year (our first summer here) I had no idea how it would grow. I'm happy to have a couple of seasons with no flowers if it means ultimately recovering it

 

Literally, that splash of green towards the top is the only bit with buds on...

 

It sounds like you are fed up with it and it does look in need of some renovation. So go for it. Try to select some lower shoots that are still looking reasonably plump and juicy and leave them to train in as Armandii says.

@ARMANDII, do you think it would refuse to reshoot if cut right back into the very gnarled trunk that a Montana forms at the base when mature? Because that would be a quick and easy way of doing a neat job, it would save having to untangle anything. But that would be "butchering"!

 

I'm only fed up with it because it looks really messy if I could cut it back to the trunk I'd be happy, providing it didn't kill it

 

Thanks @ARMANDII when/if would i be able to?

 

I've got the fear I've finished off the buddleia :(

 

I'll take some better pics tomorrow & post them on this thread @ARMANDII . From memory though the lowest shoots are quite high :( the previous owners really left it to go :(

The buddleia was cut about 6" from the ground, as it was really bent due to the winds a couple of months back.

I guess I could always replant if I do mess things up

 

Right, I've got some more pics of the clematis...
This one is showing the lowest leaves, coming off the main trunk. This branch is also one which has grown into the climbing rose next to it

An underside view of where the majority of the growth is. It's so top-heavy it's pulling the trellis off the wall. Everything south of this is just wood

View to the top left of the trunk, this is where it's at it's thinnest but the growth is still very high up the wall.

This is about the lowest branch with new growth; should I give up on the rest and cut down what will likely end up being about 2-3" off the ground?