Dakota Gardener: Winter protection for tender roses

We have been blessed by an unusually lovely fall in the northern Great Plains. Unfortunately, the long-range weather forecast promises that all good things must come to an end. Before winter is upon us, gardeners should consider protecting tender roses. Most hybrid tea, floribunda and grandiflora roses were bred for warmer climates and cannot survive northern winters without protection.

Resourceful gardeners have devised many methods to protect tender roses. Regardless of the method, timing is important. Gardeners need to wait until the rose is completely dormant after several hard freezes. Considering that dead rose leaves can harbor spores that can cause next year's fungal diseases, cleaning up plant debris is also important.

The styrofoam cone method used to be the most popular but has fallen out of favor for many reasons. The cone traps moisture that can lead to rotting. Research also shows that cones can heat up on sunny winter days and cause the plant to come out of dormancy. This can lead to winter damage or outright plant death. Styrofoam cones are an eyesore in the landscape and they can blow across the neighborhood if not adequately secured against winter winds.

Other winter protection methods are better because they insulate the plant and minimize temperature variability. Essentially, we want the plants to avoid freeze and thaw cycles. One method is to pile a well-drained media such as compost to a depth of 10 to 12 inches over the base of the rose. After the compost has firmly frozen, another foot of leaves or straw can be added to the pile and retained by creating a chicken wire cage. To protect against rotting, a fungicide should be sprayed on the canes prior to burial.

The ultimate winter protection for roses has its origins in Minnesota. The Minnesota tip method involves tipping the plant into a hole dug next to the plant. First, tie the rose canes together using soft fabric to create a more compact bundle. Then apply a fungicide and dig a trench in the soil adjacent to the plant's base that will accommodate the height, width, and depth of the rose. Next, use a spading fork to loosen the soil around the plant roots on the opposite side and tip the plant into the trench. Make sure to remove the soil from the crown of the plant. If done correctly, only the roots will bend. Then cover with the remaining soil. After the soil has frozen, cover with another foot of leaves or straw.

If this sounds like too much work, you can plant hardy shrub roses that don't require winter protection. The Canadian Artist Series of roses were bred to be winter hardy and disease-resistant. The cultivar, Campfire, was so successful in my garden with its prolific yellow, red and pink flowers that I added Emily Carr as a lovely focal point in the front yard.