Szerlag: Protect your new roses from Old Man Winter
If you’re a bargain hunter and scored some great end-of-season buys on roses, it’s a good idea to give them some winter protection. The folks from the mail order house Heirloom Roses in Oregon, (heirloomroses.com/info/care/how-to/protecting-roses-for-winter/) recommend winterizing any roses planted after the first of July, including those hardy shrub and own root roses.
Roses are winterized to protect them from the freeze/thaw effect that happens on sunny days and minimize windburn.
The easiest procedure is “hilling up,” or piling up loose soil in the center of the shrub to a depth and width of 12 inches by 12 inches. Don’t try scraping loose soil from the area around the bush as you may expose and damage the roots. Take soil from another area in the landscape or purchase it from a garden center. Good organic and/or mulch or a mix will also work.
After the holidays, you can use evergreen boughs banked up around the rose bush to further protect the stems and stabilize the pile. In spring, when the chance of heavy frost is past, the soil is washed away with a moderately stiff stream of water.
Gardeners who grow the more tender hybrid teas and grafted roses may choose to also use the white Styrofoam rose cones for winter protection in addition to hilling up. To keep heat from building up inside the cones when the sun shines, the cones need to be well ventilated. The Heirloom Rose folks suggest cutting four or five 1-inch holes around the top and bottom of the container to prevent the interior from over-heating. A stone or brick placed on the top of the cone will keep it from blowing away.
Roses should not be pruned until spring, when all threat of a hard frost has past. However, long stems that whip in the wind should be shortened and secured to a sturdy pole, especially on grafted roses.
Before hilling up your roses, be sure to remove fallen leaves beneath the shrub that may harbor insect eggs or fungal spores.
Mulching the surface of the soil surrounding the rose bush with 4 or 5 inches of organic mulch will help hold moisture during the winter and prevent the freezing and thawing of the soil.
Roses grown in containers will not survive if left outdoors. Move them into an unheated garage. Before the soil freezes give them a light watering monthly. A few ice cubes on the surface of the pots are good insurance should spring arrive unannounced.
Nancy Szerlag is a master gardener and Metro Detroit freelance writer. Her column appears Fridays in Homestyle. To ask her a question go to Yardener.com and click on Ask Nancy. You can also read her previous columns at detroitnewscom/homestyle.