By Jackson & Perkins
Photograph courtesy of Jackson & Perkins
If you live in USDA Plant Hardiness Zones 1 through 6 and parts of 7, you will need to protect your roses from the damaging effects of harsh winters. Most of all, remember that healthy roses are stronger: Fertilizing and watering regularly during the summer and fall growing seasons will make your plants better able to withstand harsh winters.
Care: October and November
Depending on where you live and how soon fall and winter come, you'll want to start protecting your roses for the winter during the fall months. Once you have had a few good frosts, leaves will start falling. Apply a dormant spray such as lime sulfur and/or spray oil. This will kill pests and fungal diseases that might try to overwinter on the plant or surrounding soil. It can also help nudge those final leaves off in autumn. Rake leaves from around your plants to prevent the spread of diseases.
Zones 1 to 6 and some of zone 7 should follow these additional fall and winter protection guidelines: For hybrid teas and floribundas: Cover the crowns with a mound of soil about 6" high, then cover the plants and mound with straw. Don't prune your roses at this time, unless there is a concern that canes and branches could be broken when loaded with snow.
Tree roses: In areas where winter temperatures are below 10°F, remove any stakes and gently dig away soil on one side. Bend your tree rose downward to the ground and cover it with straw first, then soil.
Climbing and groundcover roses: Cover the base of your climbers with soil. Tie the canes and wrap them in burlap. For severe-winter areas, anchor the canes to the ground and cover them with straw.
In zones 7-8, protection is usually not necessary, but roses can benefit from applying mulch over the crown area if a cold winter is forecasted. If less winter protection is your goal, always select varieties that are winter hardy to the climate zone.
Winter Care: January and February
In zones 9 through 11, roses usually don't go completely dormant, but it still is a good idea to rejuvenate them at this time. Remove all the old leaves, prune out weak, spindly or diseased canes at the base, remove any canes crossing through the center, then prune remaining canes back by one-third to one-half.
Late winter is the time to prune your roses. The killing freezes have passed and the roses are just starting to break dormancy (buds are swelling).
Water your roses if there is no rain or snow for more than two weeks, to keep roses healthy and prevent them from drying out. Be sure to remove the soil mound and any other protective covering when buds begin to swell in spring.
Again, if less winter protection is your goal, select varieties that are winter hardy in your climate zone.