Winterizing Roses

Not all roses are completely hardy in the Chicago area and require winter protection.  The goal of winterizing roses is to keep plants dormant throughout the winter, which protects them from the cold temperatures. Hybrid tea, floribunda, grandiflora and the majority of climbing roses require winter protection. Shrub roses are generally hardier, however, we still advise protection.  Tree roses and container roses also should be protected in the winter; however, the winterizing steps for these types of roses are different than those for garden roses and are listed at the end of this handout.

WINTERIZING GARDEN ROSES

1. Begin winterizing after there have been three consecutive nights of temperatures in the 20 degree F range. This will ensure that the roses are dormant.
2. With the exception of climbing and shrub roses, prune branches (or canes) to 30” tall. This will prevent wind from blowing them around and severing the feeder roots.  Do not prune canes all the way to the ground since the roots draw carbohydrates from the canes during the winter.  It is unnecessary to prune shrub roses, unless you are removing weak or unwieldy canes.  Climbing roses should not be pruned, as best flowering occurs on old wood.  Canes can be detached from their trellis and buried under 8” of soil, or wrapped in either burlap or in synthetic covering such as “Polar Planket”.
3. Strip the foliage off the canes and rake any fallen foliage from the ground. Dispose of the leaves to prevent fungal diseases from surviving and re-infecting the plant next season.  While the temperature is still above 40 degrees F, an application of an anti-transpirant, such as Wilt-Pruf, may be helpful for protection against the drying effect of winter winds.
4. When the soil is frozen, place a rose collar around the base of the plant (crown) and cover the crown with 8-10” of topsoil to protect the graft union.
5. After the topsoil dressing is frozen solid, fill the collar with organic mulch (shredded leaves or bark). This will help prevent the soil from thawing out during a warming trend in the winter.  For shrub roses, mulch with a 2-3” layer of shredded bark, as you would for other shrubs in your garden.
6. Leave the mulch in place until the beginning of the spring thaw (usually around March).
7.  

WINTERIZING TREE & CONTAINER ROSES

Tree roses have two grafts that require winter protection.  Bury the tree rose below 8” of topsoil in a shallow trench.  This requires raising the root ball to lay the tree in a horizontal position.

When dormant, containerized tree roses should be stored in an unheated garage after three consecutive nights of temperatures in the 20 degree F range.  Give the tree a thorough watering once every 4-6 weeks or when the soil surface feels dry.  Return the tree rose to the outdoors when the weather permits, usually in early May.