By Cestina
South Bohemia,
Czech Republic 
I am wondering whether wisteria will withstand temps of below -15C which is what it is listed as in my RHS book. Occasionally the temps drop to -30 here in the Czech Republic though it does not usually stay at that for long.
Clematis is very happy here......
10 Jun, 2011
Answers
I have a number of them in South Western Ontario, Canada. Our temps can get quite cold. No problems at all.
11 Jun, 2011
Many thanks :-)
11 Jun, 2011
I thought the same also. Very hardy when dormant.
11 Jun, 2011
I have a book on climbers which says they can tolerate Zone 5 which I believe is down to -29C
10 Jun, 2011