Horticulturists with Iowa State University Extension and Outreach advise that all roses need some attention before winter arrives. They advise that most modern roses require protection during the winter months and one such way is to mound soil over the base of each plant. Also, styrofoam cones need insulating material added to protect plants. Soil should be placed over the base of the plant before the cone is secured over the roses, also, several holes should be around the top of the cone to allow for ventilation.
For more information regarding roses and winter click here.