Cutting back climbers?

I got a potato vine Jasmine (solanum jasminoide) and a couple of Clematis'...

Do I need to trim them back at all? Snow falling off the roof last March chopped the jasmine down to a twig and it seemed to grow faster since, would it be worth hacking at it now? (Lovingly hacking of course)


Sorry pic is blurry as phone cam is poop!

 

Solanum can be rampant and I found cutting back the one I had did make it grow more profusely. It's your choice whether to trim it in preference to hacking. Sorry I can't help you with the Clematis, they won't grow in my garden.

 

It rather depends on the species. They are variable in the way that they grow and flower.

 

If they are early flowering do not prune as the flowers are on last years growth, but you could just remove it a trim removing any dead wood,
If they flower after June yes prune now.
The easiest way to remember it is,
If it flowers before June do not prune
Clematis are split in to 3 groups,
Group 1, Early flowering
Group 2, Large flowered hybrids
Group 3, Late flowering

 

And to add to Ian's post.....trace the old tangled stems of Group 2 clematis back to the highest pair of green buds, cut above this, untangle the stems gently, if you can, and tie them fanned out onto the support. Late flowerers like viticella or texensis hybrids (usually strong growers that have masses of small flowers, like Etoile Violette or Abundance, Princess Diana and Gravetye Beauty) you can cut down almost to ground level where there should be lots of strong new shoots.

 

Thanks all now I just need to find out what one of the clematis' is, the other is an evergreen (nunns gift) which I will leave grow as she's starting to flower.

 

Ah no way! Never mind, will make it a little teepee to climb up. Thank you