Russian E-mail Wintering The majority of grades of clematis have high winter resistance. They are capable to maintain frosts up to -30°C and – 40°C with application of shelter. Use the shelter in those zones, where the roses are covered. To shelter plants we begin after autumn cutting, at approaching steady frosts and in dry weather.To this time plants pass the period of strengthening. Zones Minimum temperature C° 1 < -45,5 2 2A From -45,5  up to -42,8 2B From -42,7    up to -40 3 3A From -39,9    up to -37,2 3B From -37,1    up to -34,4 4 4A From -34,3    up to -31,7 4B From -31,6    up to -28,9 5 5A From -28,8    up to -26,1 5B From -26    up to -23,3 6 6A From -23,2    up to -20,6 6B From -20,5    up to -17,8 7 7A From -17,7    up to -15 7B From -14,9    up to -12,2 8 8A From -12,1    up to -9,4 8B From -9,3    up to -6,7 9 9A From -6,6    up to -3,9 9B From -3,8    up to -1,1 10 10A From -1    up to +1,7 10B From +1,8    up to +4,4 11 > +4,4 As a cover it is possible to use twigs of pine which the basis of a bush and lianas, lowered from a support are covered and then they are covered with polyethylene film. In the spring the bushes are uncovered when the threat of large spring frosts passes by but before the beginning of vegetation. Last time in the literature (USA, Europe), in the description of clematises there are references to zone of cultivation which are determined by average minimal negative temperature.Our nursery is located in 5-yh zone. All clematises, presented in our catalogue are cultivated with successfully from 3 to 9 zones, if all agrotechnic measure are correct.