Try this from the archives:
http://faq.gardenweb.com/faq/lists/peren/2002104341005782.html

As for clematis, I would stick to either the alpinas (pruning group 1) or the viticallas (pruning group 3).

Among my favourites of these are Venosa Violacea and Madame Julia Correvon.

If you look here you will find more about them:
http://www.clematis.hull.ac.uk/clemlistsearch.cfm

And here, some help on growing them:
http://faq.gardenweb.com/faq/clematis/

I have just such a growing season here in my zone 3 garden. I have MANY large flowered Jackmanii types in which are cut back hard and bloom freely on the current seasons new growth. I have had no problem with hardiness as most all my plants are grown up against the foundation of the house where the roots stay warm during winter. ALTHOUGH, I know many of these types are exceptionally hardy and can be grown in the open ground! My sister has several large flowered clematis, which survive and thrive being planted against her trailer where they receive NO additional heat as the place is without any foundation Her clematis are deeply planted and this is something I would strongly suggest for any clematis being growin in COLD climates! In zone 3 or colder, IÂd also HIGHLY recommend that the large flowered types be hilled up with a deep layer of peat moss. One can also grow the integrifolia types some of which produces rather large bell shaped flowers. Pamjat Serdsta is one such that performs very well for me without requiring any winter protection!

Greg, there are all sorts of interesting and beautiful plants in which can be successfully grown in cold zone 3 ... others here will be able to guide you along with such choices.

Terry

We have a Jackmanii and a Huldine sharing a trellis on the east side of our house here in Zone 2b. They have been there for almost 30 years and grow to 12'again each summer.I had to extend the trellis after this picture was taken last year. This year we had a few blooms up to the first of November.{{gwi:627177}}