With the exception of certain shrub roses, roses need winter protection to survive in Minnesota. Light freezing is acceptable, but when temperatures reach 15-20 degrees, covering is necessary.
There are different ways to achieve this winter protection. Rose cones often provide adequate shelter. Mound soil around the base of the plant, fill the rose cone loosely with mulch, and again mound soil around the base of the cone. Poke a few small holes in the cone for air circulation. Anchor the cone against the wind.
An alternate method is to mound soil around the base of the plant, circle the plant with a wire fence, and fill this fenced area with at least 12” of mulch (straw, hay, or very dry leaves). An adaptation of this is to put 18”-24” of straw or marsh hay over the plant (after mounding 6” of soil at the base). Drive stakes into the ground on both sides of the area and zigzag twine between the stakes to hold the mulch down.
The most effective method is called the “Minnesota Tip” method. This involves digging a 6”-8” deep trench on one side of the plant, extending from the base and going out far enough to accommodate the height of the plant. Tie canes together, loosen the roots gently with a pitchfork, tip the plant over slowly, and cover the plant with soil, filling the trench. This is usually done about the third week of October, depending in the weather. In early November, place 12” of leaves or 6” of straw or hay over the plants. This covering should remain in place until April 1-15. Slowly remove it as the weather warms.
Whichever method you choose, pull off the leaves on the rose plant before covering it. Rake up any fallen leaves and remove those also. Spray the plant with an insecticide/fungicide chemical to lessen the chances of insects and diseases wintering over. Also consider using rodent bait to reduce mouse damage (read label directions carefully). Although some pruning can be done so the rose “fits” into its winter protection, major pruning should wait until spring.
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