Winterizing Rose Bushes
Learn how to winterize roses to ensure plants sail through the frosty season without harm—and greet spring ready to grow.
Guard your roses against cold weather damage by learning how to winterize them. The reason for winterizing roses is to keep plants dormant through winter so tender stems aren’t damaged by cold air temperatures. The process isn’t difficult. Learn how to winterize roses using simple materials and even simpler techniques.
The real danger to roses occurs when winter air temperatures drop below 20° F for extended periods of time. This type of winter weather typically occurs in Zones 4 and colder or at higher elevations in Zone 5. In these areas, winterizing roses is the key to ensuring winter survival. Hybrid tea roses, Floribundas and Grandifloras all benefit from winterizing, as do many climbing roses. Shrub roses tend to be hardier.
Winterize roses after a killing freeze but before the ground freezes. Some gardeners suggest waiting until three consecutive nights in the 20° F range. You want to be sure roses are dormant before starting the winterizing process.
To winterize rose bushes, gather canes together with twine to reduce damage by whipping winter winds. If your roses are in a windswept area, consider pruning branches by one-half to one-third before twining. In a protected location, you may be able to skip the twine. Knock any remaining leaves off plants (it’s okay to leave hips). Gather rose-related plant debris from beneath plants and destroy it to helps prevent rose diseases from overwintering.
After tying canes together, bury the rose’s crown by heaping soil in a mound around the base of the plant. Aim for a mound roughly 12 inches wide and deep. Bring this soil from another part of your garden—don’t scrape it up from around the rose or you risk damaging roots. If you want to use a material like wood chips or pine bark to winterize roses, that’s fine. Just increase the depth to 12 to 18 inches.
You can layer additional insulating materials, like evergreen boughs, shredded bark or chopped leaves, onto the mound after it freezes. Otherwise, you’re creating the ideal habitat for rodents to hole up for winter.
Some gardeners surround roses with a bottomless bushel basket or cylinder of chicken wire or burlap, stuffing the framework with shredded leaves or mulch. Foam rose cones also protect plants. Prune roses to fit inside cones, and place ventilation holes around the top edge to allow air flow. Bury the cone edge in soil, and add a brick on top to keep it in place. In coldest zones, heap soil over rose crowns before adding cones.
Mistake No. 1: Planting Too Late
Making late additions to the landscape can result in devastating losses next spring, especially in areas where the ground freezes. Perennials are the most susceptible to late planting, as alternating freezing and thawing of soil literally shoves plants out of soil, exposing crowns. Shrubs and trees can go into the ground later, but for best winter survival rates, you should have all plants in place by six weeks before soil typically freezes.
Mistake No. 2: Pruning Shrubs
Pruning causes plants to produce new growth, which is tender and highly vulnerable to freezing temperatures. Wait to prune shrubs, including butterfly bush and caryopteris, until spring, when all danger of frost has passed. At that point you can remove any winter killed branches. In future years, aim to get pruning done by late August, so plants have time to harden off before freezes arrive.
Mistake No. 3: Planting the Wrong Varieties
Fall lettuce crops can linger well into December in mild winter areas. Plant cold-tolerant varieties to ensure the longest harvest period. Good choices for fall planting include ‘Four Seasons’ lettuce (shown), ‘Arctic King’ and ‘North Pole.’ To overwinter lettuce in regions with cold winters, plant ‘Winter Marvel’ or ‘Brune d’Hiver.’ In mild winter areas, sow seeds of ‘Four Seasons’ or any oakleaf type.
Mistake No. 4: Not Watering New Trees
Trees that you plant in fall need consistent watering as they enter their first winter. If winter brings frozen soil without snow, give your tree a drink during any times of above-freezing temperatures. One hose-less way to ferry water to a tree is with a water bag in a cart.
Mistake No. 5: Failing to Deadhead Self-Sowers
Plants that self-sow aggressively in the landscape can be beautiful in bloom, but a gardener’s nightmare if allowed to go to seed. Clip seedheads on plants that tend to self-sow heavily in your garden. Good candidates include joe-pye weed, goldenrod, boltonia and black-eyed susans.
Mistake No. 6: Skipping Mulch
A winter mulch can be a gardener’s best friend, especially around new additions to the landscape. That extra mulch layer can help prevent frost heave around new plants that may not have an extensive root system to help keep them anchored in soil as it freezes and thaws. Put a 2-inch-thick layer around the base of plants to insulate roots.
Mistake No. 7: Spraying for Weeds
Be sure to read the label of your favorite weed killer. For common chemicals like Round-Up, 50°F is usually the lowest temperature where the product remains effective at killing weeds. Many plants essentially stop growing as soil temperatures fall into the 50-degree range, so at that point spraying is a waste of time and money. The answer is to spray early in the fall season, while plants are actively growing and air temps are still in the ideal 60-degree range.
Mistake No. 8: No Pre-Snow Clean-Up
Mistake No. 9: Not Destroying Veggie Crops
It’s vital to destroy spent vegetable crops, especially those that hosted problem pests, like Mexican bean beetles. Don’t toss these plants into a compost pile unless you know it heats enough to destroy pests and eggs. It’s safer to dispose of infested plants and fallen leaves in bags you put at the curb for garbage pick up.
Mistake No. 10: Failing to Use Frost Blankets
If you have a garden that’s actively producing when frost threatens, there’s no excuse for not investing in some season extending equipment to keep the fresh flavors—and nutrition—coming into your kitchen. This kit costs under $25 and comes with built-in hoops and the ability to extend up to 18 feet.
Mistake No. 11: Letting Grass Grow Too Long
In snowy regions, grass that goes into winter without being mowed is more prone to develop snow mold. Try to give grass one last cut before winter snows arrive. Also, once the ground freezes, stay off the lawn. Frozen grass is more prone to breaking as you walk on it, which can damage individual grass crowns.
Mistake No. 12: Not Wrapping Vulnerable Shrubs
Take time to wrap shrubs and small trees with a winter coat of burlap for protection against cold temps. Plants at risk include those with borderline hardiness and evergreens prone to winter burn. Spray evergreens with an anti-transpirant before wrapping in burlap. Before adding the burlap, protect trunks against chewing rodents by tossing mouse bait that’s enclosed in a protective container near the base of the plant.
Mistake No. 13: Failing to Protect Trunks
As food sources become scarce, rabbits, mice and voles can make quick work of bark on unprotected trees and shrubs. Use tree guards around young tree trunks, and surround shrubs with hardware mesh. You can also try to attract raptors like owls and hawks, which prey on these mammals, by erecting artificial perch poles.
In Zones 5 and 6, winterize rose bushes by mounding soil over rose crowns. If your area is prone to prolonged periods below 20° F, add a mulch layer over the soil mound once it freezes. Or use the idea of creating a frame that you stuff with leaves or mulch.
In mild-winter Zones 7 and 8, winterizing rose bushes is a quick task. In these areas, your greatest concern is repeated freezing and thawing of soil, which can push plants out of soil. This process, called heaving, is easily prevented by adding a 3-inch-thick mulch layer around roses after the ground freezes.