How to Care for Rose Bushes in Cold Climates

Whether grown in a rose garden or as part of a larger perennial bed, the survival of rose bushes during a harsh winter is a major concern for rose gardeners in northern climates. Protecting rose bushes starts with planting tough roses then developing a rose care plan.

Types of Roses

Rose species are propagated from wild roses. Shrub roses are hybrid plants bred from rose species. Old roses are from varieties created around the mid nineteenth century. Modern roses include hybrid teas, floribundas and climbers. Roses with a history of harsh winter survival include:

• Carefree series shrub roses – hardy repeat bloomers with good pest resistance.
• The Explorer series shrub and climbing roses – bred in Canada for winter hardiness.
• Rosa ‘William Baffin’ – best hardy climbing rose.
• The Knockout rose series – shrub rose developed in Wisconsin. Repeat bloomer is pest resistant and winter hardy.
• New Dawn – climber, hardy and disease resistant.
• Rosa ‘Bonica’ is a shrub rose. All America Rose Selections winner in 1987.

Gardeners should check plant tags for specific cultivar information. Look for rose information indicating whether the plant has been grafted.

Grafted Roses

Some roses are grafted onto hardy rootstock. This will help the roots withstand freezing temperatures, however from the graft point and above winter damage can occur. To protect roses, plant the grafted point two inches below soil surfaces.

Select grade one roses are the best bare-rooted roses to purchase. Gardeners should look for thick canes and large roots. The canes will be dormant. Before planting in early spring after danger of frost has passed, soak several hours.

Potted rose plants should only be purchased if they have been hardened off. Plant after danger of frost is gone.

Shrub roses are not grafted; these can be planted at the same level as found in the container.

Planting a Rose Bush

Roses should receive six hours of sunlight, preferably facing south or east. For good air circulation, space roses ensuring light reaches all sides of each plant.

Soil must be well draining, applying two to four inches of organic matter to clay or sandy soil. Organic material should be worked into the top foot of soil.

Watering and Fertilizing Roses

Roses need one inch of water per week. In clay soil, the total amount can be applied once but in sandy soil space out the applications. The top two to four inches of soil should be dry before watering. Apply water using a soaker hose or watering wand avoiding the leaves.

Use a soil test to determine levels of phosphorous and potassium before applying more to a rose garden. Low nitrogen, slow release fertilizer can be applied to roses.

Fertilizer for species, shrub and climbers should be applied in early spring. Repeat bloomers should receive a fertilizer application in early spring and, again, after the first bloom. Do not fertilize roses late in the season.

Pest management is essential to have healthy roses; it is the best chance for surviving harsh winters. Pest resistant cultivars are a wise choice for this reason.

Winter Care for Roses

For grafted climbing roses use the Minnesota Tip Method from the University of Minnesota Extension to protect plants over winter. It is a reliable method to save climbers. Other methods to protect roses include using rose cones or by mounding organic material.

Protect roses with cones by following these steps:

• Cover roses after a week of freezing temperature.
• Tie and prune back canes.
• Cover the base of the plant with eight to ten inches of soil.
• After this freezes, cover rose with rose cone, add a layer of straw between plant and cone for additional insulation.
• Cover the edge of the cone with soil.
• Use cones with removable vents or add vents by punching holes near the top on sides that face away from wind.
• In spring, gradually remove mulch as temperatures increase.

The mounding soil method is another way to save roses:

• Surround the rose plant with hardware cloth and sink into soil, starting after a week of freezing temperatures.
• Loosely tie canes, prune very long canes.
• Mound eight to ten inches of soil around the base.
• After soil freezes, mulch base of plant with evergreen boughs or straw.

Visit northern botanical gardens with hardy rose collections. Kingwood Center grows a selection of roses hardy for the region.