Hi, I have one of these and mine is also massive, what I am currently doing with mine is just winding some of the new growth around the old wood to disguise it and cutting off new growth which I dont want, if you are going for a hard prune, now is the best time to do it.

Good idea Marion. I found that they will take a really good hard prune ....unlikely to kill it that way I think...but the harder back you go, the less likely to get flowers next year. Mind you, I don't know that my advice from way 'up north' is going to be that useful to you in lovely southern parts where no doubt it will grow twice as fast! It's really up to you freeas....depends what you mean by 'ruin it'....if you're worried, go cautiously! :D

thank you Marion and Karensusan,
I would like to go for the 'hard' prune but will more likely just trim back some of the new growth, because it is a magnificent plant.That way it will still look good this Summer, and should grow enough to produce flowers for next year. It's funny that you think Oxfordshire is very South [its more South Midlands!]but still a lot warmer than where you are I guess [Scotland?]

Yup, N. East coast....about 80 miles n. of Edinburgh and 15 East of Dundee. :D

Freesa, believe it or not but I have 3 in my garden, (and its not a large garden) I put one up to cover the ugly garage walls and corogated roof, and it is doing a great job, the roof is half covered now. I planted one in the corner of my garden and although there is a gap between the garden and the house wall I managed to train it all the way up the house wall, I just started doing that last year and the whole wall is nearly covered, and the other one is by the gate as you walk into the garden, I keep this one, trimmed as there are other things around it but I just keep twining and twining the new growth around the old growth and I have ended up with a lovely large bush like Montanna, I cant be without mine as what a show they give us when in flower. To give summer interest I have planted loads of summer flowering clematis in them which I picked up from Morrisons for £1.79, they take a year or 2 to really get going but I figure for £1.79 its worth a little wait and these ones are really easy to prune in February.

That sounds wonderful Marion!

yes, what a very good idea Marion, to get some Summer flowers in there, I will have to try that once I have done the 'prune'. I have also planted a new Montana on the pergola and that is really doing well with all the rain, as they seem thirsty plants.Its a new one called [i think] something like Freya or Freda.Its a smaller flower but more purple -ish leaf colour and a deep cherry pink flower.

Oh yes, that's Freda Freeas....I love that one. Not so rampant and a wonderful colour. I don't think it is new though....well, at least 15 years old I would think, as I had it in my old garden that long ago I reckon. Actually, I did prune it back once and it didn't flower for a couple of years. Pruned it at the advised time...but up here things take longer to recover.

I also agree with you saying they are 'thirsty'. Once I cottoned on to that I had much more success as I started to water mine a lot more, and they loved it.

I have just googled the Freda Montanna and oh what a gorgeous colour, I am envious now Freesa as I have no room left to plant one.

yes Marion, the Freda is a lovely colour, you will have to get one, there's always room for one more plant! I did think it was a new clematis, but Karensusan says not[maybe my garden centre just advertised it that way for sales!]