Preparing Roses for Winter
I have had several questions coming in from various places around the country asking about winter rose care.
Most roses can withstand a quick cold snap of 10 degrees, but it is best to protect them if you expect an extended period of time when temperatures dip under 20 degrees F. The amount of protection your roses need depends on the climate in which you live.
In the northern areas of the country in Zone 4, which includes states such as South Dakota, Maine, Vermont, Northern Iowa, and Minnesota, winter rose care begins after the first hard frost, usually around mid-October and if possible, before the first snow fall.
The first step in protecting bush-type roses, such as hybrid teas, floribundas, and grandifloras is to loosely tie the canes together to keep them from whipping around in the wind. Then cover the base of the plant with 12 inches of soil. Straw or leaves can be placed over the soil mound for additional insulation.
If you prefer to use styrofoam rose cones, prune the bushes back so the cone will fit over the plant. Before you cover the bush, mound several inches of soil around the base of the canes then place the cone over the rose. To keep the cone in place, mound soil around the outer base.
To protect climbing roses, remove the canes from their support and carefully bend them to the ground. Hold the canes in place with pegs or stakes and cover with several inches of soil. This should be done after the roses go dormant and have been exposed to two or three hard freezes.
Depending on spring weather conditions, remove protective materials before the buds break open, normally in late March to mid-April.
In states such as Ohio, Indiana, New York, Kansas, Missouri, Pennsylvania, designated Zone 5 or 6, since the winters are not as severe, you can protect your roses as mentioned above or simply pile protective material around the base of the plants. Another option is to create a chicken wire cage filled with leaves around the base. Your main concern is protecting your roses from extended periods of weather below 20 degrees, winter winds, and fluctuating temperatures.
For states in Zone 7 and 8 such as Arkansas, Mississippi, Georgia, Alabama, North Carolina, the biggest danger to roses is when temperatures rise and fall causing the ground to freeze and thaw. This often results in frost heaving of the roots from the ground. To prevent that from happening, mound at least 2 to 3 inches of mulch around the base of the rose. To avoid attracting rodents and insects, keep the mulch away from the trunk of the plant.