"Klara" wrote in message
...

Charlie, I'm not sure which we have, but it has quite large flowers. The
first summer it flowered all summer, but that was presumably something
the nursery had done, e.g. prune it much earlier?
But as we have no conservatory, do you think it will survive in the
house over winter, or should I board it with someone with a conservatory
over winter (thus presumably missing all the flowers, since it seems now
to have rejigged itself to winter flowering)?

--
Klara, Gatwick basin

Its almost certain you will have T. urvilleana. The main problem with
overwintering in the house is its size when brought in! since there is no
point cutting it back until flowering is over.
I expect that it had been kept originally in a heated greenhouse, hence its
confusion as to what season it was. Other people (not me) can grow it
outside down here. it will go down to 0 but any lower and you normally lose
it, or it takes so long to recover it fails to flower the following year.
Once you have some cuttings, why not try a bubble wrap shelter outside
against a warm wall, so you can cover for cold nights and enjoy the flowers.

--
Charlie, gardening in Cornwall.
http://www.roselandhouse.co.uk
Holders of National Plant Collection of Clematis viticella (cvs)