Next, mound soil 10 to 12 inches high around the canes. Place additional material, such as straw or leaves, over the mound of soil after the ground freezes. A small amount of soil placed over the straw or leaves should hold these materials in place. Many home gardeners protect their bush-type roses by placing styrofoam rose cones over them. Unfortunately, rose cones by themselves do not provide adequate protection.
Additional material is necessary.
If using styrofoam rose cones, prune the canes back to allow the cone to fit over the plant. Remove any plant debris, then mound 6 to 8 inches of soil around the base of the canes. Set the cone over the plant. Finally, mound a small amount of soil around the outside base of the cone to keep it in place. Secure the cone by placing a brick or other heavy object on its top.