Erm, there isn't a white flowered Jasmine that would have flowered and finished by now, I'm afraid. Do you mean Clematis armandii? If you do, any pruning you need to do should be done now, as the flowers fade.

Thank you for replying it is ajasminum polyanthum star it has been flowering for a couple of months now and there are a few flower still in bloom

Well, I'm astonished - Jasmine polyanthum is not entirely hardy, and although we've had a mild winter, given where you are, I couldn't think it had survived outdoors and flowered late winter and spring. But clearly, it has! If you want to prune it back, do so once the flowers are finished. Ultimate height, if it survives, is up to 2.5 metres, with a spread of 1.5 metres. You may just want to tidy it up a bit instead, rather than heavy pruning.

My climbing Jasmines have only just come into leaf (and I'm a lot further south than you), and won't be flowering until next month, so I too am astonished. Are you absolutely sure they're Jasmines? Is it possible that they were mislabelled by the nursery?

I don't know what to say. I'm 100% sure is a jasmine pink buds that turn in to white flowers when open and a lovely fragrance. if I get the chance I will take a picture :)

Just noticed it still has a few buds of it so it might last a while longer :)

That is definitely Jasminum polyanthum - it does flower earlier than Jasmine officinale, but I've only ever seen these flourishing outdoors in London or the West Country, always in sheltered sunny spots against a wall. We lost ours in that cold winter of 2010.

I have just found the label and it does say it flower until July so may only get to June as it started flowering a month early. Will have to remember to protect it over winter when temp is below 0.