Not all roses need winter protection, but for those that do, here’s how to prepare them for a long winter nap.
Summer is just a memory now for gardeners as they clean and stow their tools and look forward to the holidays. But before you get sidetracked, have you thought about putting your roses to bed for the winter?
Some roses, such as hybrid teas and those that are grafted (attached to the roots of a vigorous, hardy rose) just can’t tolerate the freezing temperatures and icy blasts that come roaring across the Midwest. Others, such as species roses, some shrub roses, and some of the old garden roses, are quite hardy and require little or no protection.
Whatever rose you grow, it should be completely dormant by mid-fall. (If you fertilized after August 15, you prodded the plant to produce tender new stems and buds. This new growth is more likely to succumb to freezing temperatures, and you’re likely to wind up with dead, blackened stems come spring.)
Some rose bushes start producing hips (the fruit of the plant) around September 1. The Chicago Botanic Garden recommends that you stop all deadheading (removing spent flowers) at that time. Allowing the roses to produce hips helps them prepare for dormancy. Rosa rugosa, in particular, is known for beautiful hips, which often last into winter and provide food for wildlife.
The greatest damage to roses and to many perennials occurs when winter weather alternates between freezing and thawing, so the goal is to keep the rose bush cold and frozen throughout winter, not warm and toasty.
Providing winter protection for roses is fairly simple. Once a hard, killing frost causes the rose to drop most of its leaves (usually late November or early December), it’s time to take action. Rake up leaves and other debris from around the base of the plant, since they can harbor disease. The canes of taller roses can be tied together to keep them secure when winter winds come whipping through your garden. (If by Thanksgiving we have not had the required low temperatures, go ahead with the winterizing.)
The Chicago Botanic Garden recommends that hybrid teas and English roses, like the David Austin® Roses, be cut to knee height after several days of temperatures in the teens.
Make a small hill (10-12 inches) of good soil or compost around and over the base of the plant. If you don’t have any good, well-drained garden soil or compost, buy a bag for each plant. Don’t be tempted to use clay soil from your garden; this can be the kiss of death for your rose since clay holds too much water around the plant’s roots.
About mid-December, this protective mound generally freezes. When that happens, you can cover the mound with leaves, straw or evergreen branches. Another way to do this is by staking chicken wire or hardware cloth wrapped around the rose, filling it with soil. Once it’s frozen, top it off with leaves or straw. The benefit of the collar is that it holds the soil and leaves or straw in place.
Many rose growers use white plastic foam rose cones. They’re very conspicuous in the winter landscape, unless we’re having a snowstorm, and they’re not recyclable when they fall apart. However, if you are considering rose cones, timing is important—they should be used after we have a hard, killing frost, or when we’ve had several days of temperature in the teens, not any sooner.
Rose cones must have ventilation; otherwise they become a mini-greenhouse on sunny winter days. The cones should have four or five 1-inch holes around the top and bottom to prevent the air inside from heating, which can cause the rose to break dormancy and begin growing—not a good thing in January or February. Even with a rose cone, soil should be mounded around the base of the plant before the cone is set in place. Place a brick or stone on top of the cone to keep it in place.
To protect climbing roses, which bloom on the previous year’s canes, you’ll need to release the long canes from their supports. Tie them together as much as possible and mound with soil. Wrap the canes from top to bottom with burlap and secure them to the support with twine. When does all this winter dressing come off the plants? Start checking for signs of new growth in early- to mid-spring. Once you see new shoots, you can remove the cones or begin removing the chicken wire, leaves, and brushing back the soil.
From Chicagoland Issue XVI Volume VI. Photos by Gene Sasse, courtesy of Weeks Roses.