1. Coax Them Into Dormancy.
Stop feeding and pruning your roses around the end of August, to discourage tender, new growth that will suffer from winter damage. Leave the last of the flowers on, to turn into hips. The hips are the rose's seed pods. By producing seed pods, the rose bush thinks it's done for the season and can start to go dormant.
2. Make Sure the Rose Bushes are Well Watered.
After the first frost, thoroughly water the soil around your rose bush. Once the ground freezes the bush has to take care of itself, so give it a good soaking going into winter.
3. Prevent Problems from Over-Wintering Near the Rose Bush.
Remove all fallen leaves to prevent diseases and insects from overwintering. If the leaves were healthy, you can go ahead and compost them. But if you had a problem with a fungus, like black spot, or an insect infestation, dispose of the leaves and get them out of your yard.
4. Protect the Graft Union.
After a couple of hard freezes, mound 6-12 inches of compost around the crown of the plant, to protect the roots and the graft union where the rose species you are growing is attached to a hardy root stock. The graft should be at or just below the soil surface. In a mild winter, you could also circle the rose with wire and stuff this cage with leaves or mulch. Don't try to use the soil around the rose bush as mulch. Moving it could expose or disturb the roots.
5. Special Care for Climbing Roses.
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Climbing roses are at risk from strong, drying winds. To protect the canes of canes of climbers, either wrap the canes together bundling something like straw on the outside for insulation or remove the canes from their trellis or support and lay them on the ground. Then tie the canes together and secure them to the ground with landscape pins. Protect with a layer of mulch.
6. Winter Rose Care in USDA Zones 7 & 8.
Zones 7 & 8 always stand the chance of a freeze and maybe even some snow. The graft union would benefit from protection, but it need not be as heavy as for zones 6 and below. Mounding with leaves or a shredded mulch should suffice. However, the rule about discontinuing pruning at the end of summer holds for zones 7 & 8 too.
7. Winter Rose Care Tip for USDA Zone 9+.
In zone 9 and above, where roses won't be subject to freezing temperatures, watch for fungal diseases that can creep in with the cooler, wet weather. Since your roses are still growing and setting buds, November is a good time for a light feeding. Prune after the plants bloom in December.
