As our weather turns increasingly fall like, it’s time to start putting the garden to bed. For rose growers, this can be a process, depending on how hardy your rosebush is. Winter hardiness among roses varies. Is your rose grafted? The rootstock can determine hardiness. Species roses and rugosa roses are generally cold hardy to our area. Roses grown on their own rootstock are a better bet for Western New York. If for some reason the top is killed by a hard winter, then the plant that grows back from the root will be the rose you wanted.
Winter protection is frequently recommended even for roses that are labelled hardy to our area. Giving your roses some extra care will help protect them from harsh winter winds, and from any freeze-thaw cycles they will endure. How much protection you provide also depends on your site. Roses planted in a more protected spot may not need as much winterizing as a rose out in an open, windy area. Winterizing roses starts after we have had a few hard freezes, as they should be dormant.
If you haven’t yet, you should stop deadheading roses. Allow them to create rose hips, as this is a signal to the plant to get ready for winter. You really should stop deadheading around Labor Day and no fertilizer after Aug. 1. As leaves fall, do a good cleanup around the bush. Spray with a dormant oil labeled for roses. This will help reduce insect pests and diseases next year. You can prune out dead branches but don’t do major pruning as the cuts won’t have time to form a callus. If rain isn’t sufficient, do a deep watering before the ground freezes.
In mid to late November, you can start to mound soil or compost around the base of the rose. Don’t dig it from around the plant, bring in fresh soil. It can be bagged soil that you bought and kept from freezing or dig it from elsewhere (approximately 5-gallon bucket) in the garden. You want to create a 10- to 12-inch mound around the base of the plant, making sure you have the center of the rose covered. This will help keep the soil temperature stable and less likely go through freeze-thaw cycles. Soil mounding too early can delay stems from maturing and entering dormancy, reducing its winter hardiness.
You can also add some extra protection like clean straw, shredded leaves, wood chips/mulch or evergreen boughs (cut from a discarded Christmas tree) on top of the soil mound. Use a cage of chicken wire to keep things from blowing away. A covering of snow will also help to insulate the plants through the winter. If mice or voles are an issue, you might want to skip this step, as they might decide this would make a good place to spend the winter.
Rabbits and deer will take advantage of exposed plant material in the winter. Excluding your roses from them with a fence is your best defense. The fence should be tall enough that the rabbits can’t walk over it after we get snow. Deer repellents can be used but must be reapplied, which is not practical in the winter. Repellents work best if used before the deer have decided your roses are tasty. Fencing plus burlap wrapped around the outside can help keep rabbits away and help prevent wind damage.
What about using rose cones for winter protection? There doesn’t seem to be much actual research about them, but many rose sites suggest using them. Traditionally they were made from Styrofoam. There are other protective covering options available too. You still have to mound up soil around the base of the plant. You will also have to prune the plant enough to get the rose under the cone. You may have to tie up some of the canes to fit them under the cone. The cones will help reduce the amount of wind hitting the plant, which is a plus. You need a good seal between the ground and the cone to retain heat from the ground. Mounding some soil around the base of the cone can work and it will help keep the cone from blowing away. One source said that roses covered before mid-November were more susceptible to winter injury than those left uncovered. Follow any directions that come with the cone. Do your own experiments to see how they perform under your conditions. I would also check on them during the winter to see if anyone made a home under them. Seems like a cozy place for a mouse to spend the winter.
Leave your roses protected through the winter and into early spring. Once the forsythias start to bloom, you can think about removing the soil, mulch, burlap, cones, twine, etc. You want to remove all of this before new growth starts, so keep an eye on your roses. Carefully take the soil mound away and remove it to another area. Be careful not to injure your canes. Wait to prune until you can see new growth. Prune out broken or dead canes.
Keeping your roses healthy through the growing season will help them withstand the rigors of winter winds, snow and cold. Look for roses that are hardy for your area and disease resistant. Roses want to be planted in full sun in fertile, well-drained soils. They also need good air circulation so give them the space they need. Well-cared-for roses are a lovely addition to the garden.
Resources: Chicago Botanical Garden, Jackson and Perkins, Heirloom Roses, University of Vermont and “Gardening in New York” by Andre and Mark Viette.
Have a gardening question? Master Gardener volunteers are normally in the office Monday through Friday, from 10 am until noon. You can stop in at our CCE office at 420 E. Main St., Batavia, call (585) 343-3040, ext. 127, or e-mail them at: email@example.com. Visit our CCE website at genesee.cce.cornell.edu or like us on Facebook www.facebook.com/CCEofGenesee.
On the first Tuesday of the month, join the Genesee County Master Gardeners for our lunch time Garden Talks from Noon – 12:45 p.m.. On Nov. 4, the program will be “A Harvest of Squash.” Do you want to know what to do with the squash that found its way into your home? This class will explain the different types of squash, how to prepare them for use, storage for later use, as well as share a few recipes for that bountiful harvest.
This free program will be held on Zoom. Please register at our CCE website events page — http://genesee.cce.cornell.edu/ to get your personal link. Programs are recorded and posted to the CCE Genesee YouTube page.