Yes, for most roses, and the job is simple. After the plant goes dormant, bury its base under 10 to 12 inches of bagged soil and save the pruning for spring. Ohio’s winters are cold enough that grafted roses regularly lose canes, and sometimes the whole top. Timing matters as much as soil. Below you’ll find who needs protection, when to start, how deep to mound, and what to skip. For planting and care the rest of the year, see growing roses in Ohio.
Do roses need winter protection in Ohio?
Most grafted roses do. Ohio runs from USDA zones 5b to 7a on the 2023 USDA Plant Hardiness Zone Map, and most of the state sits in zone 6a or 6b. That map rests on a single variable, the average yearly extreme minimum temperature. It describes a typical coldest night, not the worst one. Across the whole range, the USDA hardiness zone is built on the average annual extreme minimum temperature, and some winters go colder than the label on the map.
Cold alone is rarely what finishes a rose. Ohio winters swing back and forth: a hard freeze, a thaw, then another hard freeze. Each cycle can pull a plant out of dormancy and split the bark on its canes. Winter sun and wind also dry out the canes while the frozen ground keeps roots from sending up replacement water.
The weak point is the graft union. Hybrid teas, grandifloras and floribundas are budded onto a tougher rootstock, and the union is the swollen knob at the base where the canes emerge. If it survives, the plant regrows from it in spring. If it freezes, the top dies and the rootstock sends up shoots of its own. That wild rose is usually a rangy plant with small flowers, nothing like the one you bought.
Which roses can skip winter protection in Ohio?
Roses growing on their own roots have no graft to lose. If the canes die back, the plant regrows true to type from the crown. Hardy own-root shrub roses, rugosas and most groundcover types generally get through Ohio winters bare, so mounding them is wasted effort.
The warmest pockets of the state, the zone 6b and 7a spots in the south, along Lake Erie and in the sheltered parts of larger cities, give the most honest “no.” There, a hardy own-root rose needs nothing at all. A grafted rose in zone 6b is a judgment call. Mild winters pass unnoticed, but one bad winter can cost the plant, and the insurance is a bag or two of soil. In the colder parts of the state, zone 5b and the colder side of 6a, leaving a grafted rose bare is a gamble that often loses.
When to start, and what triggers it
The trigger is a run of hard freezes. The calendar only gives a rough window. In the zone 6a part of Ohio, the first fall frost lands between October 5 and October 15. That first frost burns tender leaves, but roses keep moving sap for weeks afterward. Bury the base at that point and the crown sits warm and damp under the soil. The plant keeps trying to grow, and rot can set in before the real cold arrives.
Wait until the plant is dormant. In most of Ohio that means mid-November to early December. Southern counties run toward the later end of that window, and the northern tier toward the earlier. By then the nights have stayed below freezing for several days running, the leaves are down, and the soil surface has stiffened without freezing solid.
How do you know a rose is dormant?
Look at the plant before you look at the forecast. The leaves have yellowed and dropped, or hang blackened on the stems. The tips have stopped pushing new growth, and the buds along the canes stay tight. In the morning the soil is firm and a little crusty on top, yet a trowel still goes in without a fight. If a warm week is forecast right after a cold snap, hold off. The soil under a fresh mound would warm back up and wake the plant.
A few chores belong in the weeks before. Rake fallen leaves away from the base, because they can carry black spot spores through the winter. Stop fertilizing after late summer, since feeding keeps soft growth coming that will not harden off. Tie the canes loosely together so wind cannot whip them around. Buy the soil early too. Garden centers stock fewer bags by late fall, and bags left outside can freeze into a solid block. Stacked in the garage, they stay workable.
How to mound, and how deep
The job is to bury the graft union, because the canes are expendable and the union is not. Pile loose soil over the base of each plant until it forms a cone 10 to 12 inches tall, with the knob of the union well inside it. A mound that low leaves the upper canes exposed, and that is fine. They may die back, but the buds near the base stay insulated at a fairly even temperature and regrow in spring. Cut canes that stick up far above the mound so wind cannot rock the plant. Save the real pruning for spring, when you can see what survived.
Plan on one to two bags of soil per bush. Bagged topsoil or a bagged garden soil mix works well. Compost blended with topsoil also works, as long as it is loose and not soggy. Pour it around and over the base, then pat it gently so it does not slump.
Why does bagged soil beat soil dug from around the plant?
Digging beside the bush cuts through the shallow feeder roots just when they need protection. It also leaves a trench around the crown. That trench fills with meltwater and freezes into a ring of ice right where you wanted insulation. Soil from the bed can also carry fungal spores from the season’s diseased leaves, and it tends to be heavy and wet. Bagged soil is loose, drains well, comes up clean, and can be handled even after the ground starts to harden.
Once the ground has frozen on the surface, add a loose layer of shredded leaves, straw or evergreen boughs over the mound. This second layer keeps the soil from thawing and refreezing in January and February, which is a pattern that does a lot of harm. Keep it loose and open to air. A packed, soggy layer only holds moisture against the canes.
What does not work in this climate
Plastic wrapping is one of the worst offenders. It looks like a windbreak, but it works like a greenhouse. On a sunny day in January the air inside warms well above the air outside, and the canes start to wake. Condensation forms, and the damp, stagnant air is ideal for canker and gray mold. When the temperature drops again overnight, the softened tissue freezes and splits. A bush left in plastic often looks worse in April than one left bare.
Do rose cones work in Ohio?
The foam rose cone is the classic example of a good idea used badly. Placed over a bush and sealed tight, it traps heat and humidity just as plastic does, and sprouts that form inside the cone are weak and pale. The cone can work as a cap over a mound if you cut a vent in the top and prop it open on warm days. Without the mound beneath it, a cone insulates the canes that are going to die anyway and does little for the union.
Can you mulch early instead?
A thick pile of mulch or leaves laid down while the ground is still warm creates the same problem as early mounding. The soil stays warm, the crown stays damp, and the plant keeps growing. Voles and mice also move in, since a deep layer of loose material over warm ground is an inviting place for them to nest, and they chew bark at the base while they live there. Add mulch after the soil surface has frozen. Leave every cover open to air, and the plant will usually come through in better shape than any sealed wrap would leave it.
Checking this against your own county
The 5b to 7a range hides real differences between counties, and between neighbors. Elevation is one of them. Cold air drains downhill and pools in low spots, so a garden at the bottom of a valley can run colder than a hilltop garden a short drive away. Your nearest county office of Ohio State University Extension can tell you the local zone, the typical timing of the first hard freezes, and how nearby winters have behaved. Call your county Extension office before deciding that your yard is the exception, because a lot of gardeners learn that lesson only after losing a bush.
Common questions
Should I prune my roses before winter?
Only lightly. Trim canes that stand well above the rest so wind cannot loosen the roots, and remove anything dead or broken. Do the real pruning in spring, once the buds begin to swell and you can see which canes are alive.
When do I take the mound off in spring?
Remove it in stages. Pull off the leaves or straw first, then clear the soil in a couple of passes over several weeks, usually from late March into April. In the zone 6a part of Ohio, the last spring frost falls between May 5 and May 15, so new growth can still be nipped after the mound is gone. Keep a few spare bags of soil or a sheet of burlap handy for a late hard freeze.
Do roses in pots need different protection?
Yes. A pot freezes from every side, so the roots are far more exposed than roots in the ground. Move potted roses to an unheated garage or shed once they are dormant, and give them a little water now and then so the soil never dries out completely. If the pot has to stay outdoors, sink it into a garden bed and mound over it as you would any other bush.
Does snow protect roses?
Snow is a good insulator, and any canes buried under it are in better shape than canes standing in open air. Ohio’s snow cover is unreliable, though. It comes and goes, and it rarely covers a whole plant. A mound is steady protection, while snow is a bonus when it happens to fall.