Cool fall weather brings on the dormant period for roses. When this occurs, it is time to winterize your rose plants. By now, you should no longer be feeding your roses. Refrain from major pruning and stop cutting blossoms. These three things only stimulate new growth which will be killed by frost.
Begin by removing old mulch from under and around your rose plants. The old mulch could harbor insect eggs or disease spores so it is best to replace it with a fresh layer. Spread fresh mulch as far out as the branch tips on the shrubs. Wood chips, shredded bark, straw, and chopped leaves are all good choices. After mulching, water the rose bush well.
Once the ground freezes, add another layer of mulch. This will insulate the soil and helps it maintain an even temperature in spite of the alternating freezes and thaws that we experience throughout the winter. As the temperatures fall regularly to the freezing mark, keep adding additional layers of mulch until the bush or tree is virtually covered.
By using a layering method, and by using the above-mentioned coarser materials, the rose plant will continue to have good air circulation. If you would prefer to keep the mulch or leaves more contained, or the area where the roses are located is particularly windy, it is a good idea to build a simple chicken wire cylinder around the plants or to use stakes and burlap in addition to the mulch.
The mulch and protection can be removed in March and the roses can then be fed and pruned for the upcoming growing season.