How well your potted rose tolerates winter depends upon what type of rose you are growing. Old garden roses are hardier than hybrid teas, according to horticulturists with the University of Illinois. The challenge in winterizing potted roses is to help them to go completely dormant and keep them consistently frozen, with no thawing, during the cold winter months.
Stop fertilizing the rose bush after August 15.
Discontinue cutting flowers and deadheading after October 1. Allow the rose plant to produce rose hips.
Remove all the leaves and hips from the rose after the first hard frost. Clean up any debris, such as twigs and fallen leaves, in the pot.
Prune the rose to remove damaged wood, branches that cross over others, and overly long canes.
Spray the branches of the rose with a fungicide, according to label directions.
Wrap the rose tree lightly. There are several methods that work well. If the rose is small enough, place a tomato cage over it and stuff leaves over and around it. The National Gardening Association suggests placing the potted rose in a burlap bag and stuffing the bag with leaves. The association also cautions against wrapping the rose too tightly, as it needs air circulation to avoid fungal disease.
Place the potted rose in an area where temperatures will not drop below 20 degrees F, such as in a shed, garage or basement. Place the pot off the floor--on a table, for instance--where the air is warmer.