I live in N.Idaho and this past winter we had so much snow and it lasted till March that many people experienced rose loss. I lost 3 big roses but not one of my minis. They were all newly planted last spring. All I did was make sure they had a good layer of pine needles and pine mulch around them. The roses I lost were well established and up against the house. The local plant expert said that the roses didn't have enough time to go dormant and when the temperature suddenly dropped in Nov. the moisture in the stems frozen and damaged the inside of the plant.