Tips for Winter Care
Knock Out® Roses are tough and can make it through anything. But, if you live in an area with harsh winters (zones 4 and below) there are a few things you might want to try.
To protect your roses, you should do the following:
In-ground: Add 2-3" of mulch, leaves, or pine/fir boughs around the base of the plant. A heavy snow cover will also help insulate and protect the plant through the winter. Also, the winter winds can really dry out the plant so you may want to wrap the plant with burlap. In spring, remove any extra mulch that may be covering the plant too deeply and trim out any dead or broken canes, also remove any burlap that you may have used to wrap the plant.
Containers: If you planted your Knock Out® Roses in containers, winterizing them is easy. To start, leave the containers outside through the first few frosts of the season, then bring them inside and store in a cool, dark area such as your basement or garage. If you store your containers in the garage, remember to protect them from the winter temperatures that can come in as you open and close the door. Keep your containers inside until the threat of the last frost has passed (typically in early spring). You'll want to check your roses periodically to make sure they don't dry out completely. If they do start to dry out, water them lightly.
Tree roses: In areas where the temperatures fall below 10˚ F in winter, tree roses should be wrapped with insulating material to protect them from the cold and wind. In the colder areas where the temperatures fall below zero, the only adequate protection for tree roses is to lift them in late fall before very severe freezing weather and bury them in a trench covering them completely with a foot or more of earth.