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from "K" contains these words:

I planed 3 of the above in a large earthenware pot last spring and they
flowered beautifully on their support. For the winter, I covered the
compost with a black membrane and bark chippings and they had recently
started to sprout new leaves. A couple of weeks ago we had a few quite hard
frosts here in outer London and I notice the new shoots have been affected.
Now I've just got a brown straggly mess. Have I lost them, or is there a
chance they will shoot again? They were so pretty and were the first
clematis I have tried in a container so I would hate to lose them.

I don't know the answer to the question, I'm afraid, except that, with a
bit of luck, there might be more buds below the surface of the compost,
which might sprout.

I'm interested in the hardiness of C. sieboldii generally as well. On
Rachel Sullivan's excellent website, (http://www.ukclematis.co.uk) she
says that Clematis florida 'Sieboldii' needs a "very sheltered
site/conservatory". In one or two other places I've looked it doesn't
specify so much protection, but obviously your experiences too suggest
that it's susceptible.

I wonder whether Rachel or anyone else can comment more fully? My baby
plant is standing outside at the moment and seems to have survived
recent frosts.

Janet G