Shrub roses are hardy siblings to the more tender hybrid tea roses. Shrub roses are easier to winterize; they don’t need to be covered completely and in some climates will survive winter without any protection at all. To ensure that your shrub roses last through the cold winter months, follow a few simple steps beginning in late summer.
Do not fertilize after early August. Fertilizing encourages the plant to put out succulent new growth that will not survive winter.
Stop removing faded flowers in late August. Allow them to remain on the plant and grow rose hips. This will help harden off the shrub rose and prepare it for cold weather ahead.
Remove the shrub rose’s fallen leaves from around its base. Do not compost them; bag them and put in the trash or burn them, as they may harbor rose pests or diseases.
Prune your shrub rose after the leaves drop. Remove any canes that are dead or diseased. Then remove any canes that are crossing or crowding others. Finally, cut the individual canes back by about a quarter of their length.
Gather the canes of your shrub rose into a loose bundle and secure loosely with twine. This will keep snow from weighing down the individual canes and possibly cause them to break under the weight of the snow.
Cover the base of the shrub roses with 12 to 18 inches of hay or straw. This will protect the roots from winter kill caused by freezing and thawing during winter. Don’t cover the canes completely because if you do there is a greater chance of mold or fungus forming on them.