Climbing or Rambling Roses: Cover the base of the plants with a mound of soil. To leave the stems on their existing supports, wrap them in burlap packed with straw and secure them with twine. In severe winter zones, remove the stems from their supports, carefully bend them over and stake them to the ground, and cover them with at 6 inches of mulch.
Container Roses: When temperatures drop below freezing, move container roses into an unheated garage or outbuilding until the weather warms up again in the spring. Check them occasionally throughout the winter to make sure the soil in the container doesn't completely dry out, but don't give them any fertilizer. Another method is to sink the plant, container and all, into the ground outdoors. Surround the exposed part of the plant with a collar or cage and fill it with straw or leaves.
Hybrid Teas and Floribundas: Apply a final dust or dormant spray before covering plants. Cover the crown of the plant with at least 6 inches of soil, then cover the entire plant and soil mound with an additional 6-12 inches of hay or straw. In harsh climates these rose types may need to be buried.
Shrubs and Old Fashioned Garden Roses: In all but the coldest zones, most shrub roses and old fashioned garden roses require little or no winter protection. In colder zones, mound the plants with straw or hay as you would with more tender roses.
Tree Roses: In all but the mildest climates, remove the support stake and lay the trunk flat on the ground. If the trunk cannot be bent without causing damage, use The Minnesota Tip method (below) to lift one side of the root ball out of the ground so the trunk can lay flat. Cover the entire plant with soil (top, trunk, and exposed roots) and mulch with an additional several inches of straw. Tree roses growing in containers can be moved into an unheated garage or outbuilding until spring.
By Ellen Brown
Mounding or "Hilling": Use fresh soil (or compost, bark, vermiculite, peat moss, saw dust, etc.) to create a mound of loosely layered mulch around the base of each bush. The mulch should be at least 10-12 inches deep. You don't have to cover the entire plant, but make sure the base of the bush is well insulated against the cold.
Gardeners in the coldest zones (6 and below) will want to take this a step further and cover the entire plant with mulch. You can do this quite easily by adding a collar around the bush made from chicken wire, hardware cloth or a tomato cage. Wrap the collar with cardboard, bubble wrap or tarp, fill it up with fresh straw and cover the top to prevent snow or rain from collecting inside. Keep the straw loose and the mulch porous to encourage air circulation and avoid smothering the roots and crown. This method usually provides enough protection for roses grown in zones 7 and 8.
Rose Cones: Another method is to add 10 to 12 inches of loose mulch around the base of the rose bush and cover it using a commercially available rose cone. These are usually made from Styrofoam and will need to be secured by some type of weight (rock or brick) to keep them from blowing away. If you're covering extremely tender roses, cut of the top of the cone and add straw for extra protection. It's also best to poke a few small holes in the sides of the cone to allow for some airflow.
Tipping: Here in Minnesota, many rosarians use a method we call the Minnesota Tip. The first step is to dig a trench. Start the digging away from the bush and work your way towards it. The trench needs to be long enough and wide enough to accommodate the entire rose bush.
Now using a spading fork, carefully pull the soil away from the area between the bud union and the main branching of the root system. You want to loosen the soil around the roots until you can bend or "tip" the bush completely into the trench. Hold the bush down into the trench and cover it with 2 or 3 inches of soil. On top of this, add 18 inches of loose leaves or straw. Around April 1st, gradually uncover the roses as the weather continues to warm up. By mid April, the roses can be lifted back into their upright positions and the canes syringed with water to prevent them from drying out.
Protecting Climbers: To protect climbing roses, remove them from their supports, bundle the canes, lay them on the ground and cover them with 6 to 10 inches of soil and mulch. Try to avoid cracking or splitting the stems when bending them.
By Ellen Brown