As the days get shorter and the temperatures fall, our thoughts turn to getting ready for winter. This includes our gardens, especially roses.
Mention roses and people usually think of tender hybrid tea roses and winter protection. In fact, there is a continuum of winter hardiness in the roses we grow here from the very hardy species through to tender hybrids. This in turn dictates to what degree one must protect them from our winter climate. Species roses like our prairie natives, the red-leaved rose (Rosa rubrifolia / Rosa glauca), or hardy rugosa types such as Henry Hudson need no protection at all. Very hardy shrub roses such as Therese Bugnet, Prairie Dawn or Hazeldean likewise need no special treatment.
Roses of the Parkland and Explorer Series should be grown on their own roots, not budded or grafted, so they can tolerate some die back of the stems and re-grow easily to bloom the next year. Normally they don't require any special care, but can benefit from some protection their first year until they are well-established. Some winters (such as the last one) are harsher than others and bushes of these two groups may die, so to guarantee survival, these varieties can also be included with the more tender types.
The English-Austin roses are another notch closer to the tender types along our hardiness continuum. They generally benefit from winter cover, although they may survive on their own depending on the winter.
The group usually categorized as 'tender' roses on the Prairies and in need of winter protection are hybrid teas, grandifloras, floribundas and miniatures. The latter are the hardiest of this group and will often survive the winter with good snow cover.
Survival and growth for all types are increased if plants are kept healthy throughout the growing season. Sufficient water, fertilizer and pest control are the three pillars to address. Water roses if the fall season has been a dry one, and stop fertilizing at the end of July.
Good sanitation can decrease disease the following year, as fungus can overwinter on old leaves. Ideally, all leaves on the ground as well as on the plants should be removed and put in the garbage. If that is too daunting a task, at least remove those on the ground and any diseased foliage on the plant.
Cut back any long stems of tender types, Austins, Explorers and Parkland roses, as the wind may whip the canes causing them to break off. Prune any broken branches and remove fruiting hips.
Delay putting cover on as late into the season as possible to let plants acclimate (plants go through physical and physiological changes before the winter); to avoid any material around the stem causing sweating and mould developing; and to prevent mice moving in to build a nest. Even the tender roses will take a few degrees of frost so there is no need to jump the gun. Usually the end of October, once the night temperatures are consistently below freezing, is a good time.
To protect the stems from cold temperatures, we want to create small pockets of air around the rose plant using insulation. The type of 'insulation' is where all the methods vary, from piling more soil around the base, to using Styrofoam cones.
Snow is one of the best choices, so shovel snow gently (we don't want to break branches) onto the plants to the height of their stems. This works, of course, only when we have snow before the temperatures get really cold.
The main method is to mound material around the base of the plant using leaves, compost, peat moss, flax or soil. If using soil, do not scrape it from around the plant, but rather apply new soil. Oak leaves are the best, according to some gardeners, as they don't compress as much as other types of leaves. Whatever material you use, try to have it dry so as to reduce rotting.
Use wire, newspaper or cardboard boxes around each plant to keep the material in place. For large beds, cover all plants and lay burlap on top.
Then settle back and wish your roses a good sleep until spring.
Lynn M. Collicutt is the former hardy rose and perennial breeder at the Morden Reseach Station. She has introduced several roses and perennials including Morden Blush, Winnipeg Parks and Prairie Joy roses.