One of the least-used methods of rose propagation is root division. The main reason root division is unpopular is that it will not work with "budded" rose varieties. Root division will only be successful with "own-root" rose varieties. Own-root rose varieties originated from cuttings from old stock rose plants. Budded rose varieties originated from grafting onto young roses. They have leapt into popularity because most nurseries only sell this variety. If you have an old rose bush that is an own-root variety, try root division to divide the old plant into two smaller bushes.
Water the rose bush generously and wait approximately 30 minutes for the water to absorb into the soil.
Dig up the rose bush and lay it down on the ground to look at it carefully.
Find a place near the center of the bush where you can cut the bush in half. Try to divide the bush so that each side will have the same number of roots and canes.
Push the knife down through the crown of the rose bush from the top. Continue cutting until the rose bush is in two pieces.
Apply the tree wound dressing to each raw edge of the rose roots and wait while the dressing dries completely.
Plant each rose bush immediately; setting each into a hole so the roses are at the same height as they were when they were in the soil previously. Tamp down the soil around the roses and water generously.