If you find it necessary to transplant a rose bush, it can easily be done without harming it if you prepare it properly. If you can't transplant in early winter or early spring when the rose is dormant, follow these instructions. Your rose bush should recover from the shock of transplanting within a few weeks.
Sever the root system. About 2 weeks before transplanting your rose, drive a spade into the soil in a circle around the rose bush about 18 inches away from the main stem. This will reduce the mass of the root system and force it to grow a mass of smaller roots within the 18 inch circle. It will help the rose bush recover faster from being transplanted.
Cut back the canes. Using this method, it is only necessary to remove about one third of the length of the rose's branches. Make each cut just above a bud or where a leaf grows out from the stem.
Prepare the new planting hole. Dig a hole about 18 inches deep and about 18 inches across. Mix two to three shovelfuls of peat moss and two to three shovelfuls of garden compost into the soil you remove from the hole.
Add about ¼ cup of slow release granulated rose food to the bottom of the planting hole. Use a garden fork to loosen the soil and incorporate the fertilizer.
Add a few shovelfuls of the improved soil to the bottom of the hole. Form a mound with the soil.
Dig up the rose. Drive the shovel into the ground in the approximate place where you severed the roots in Step 1. Continue to circle the plant, digging deeper with each pass, until you can work the shovel under the rose bush. The plant will rock back and forth when it has been loosened enough to remove from its present position.
Carefully lift the rose bush and place it on top of the mound of soil in the prepared planting hole. Spread the roots so they are trailing down the mound of soil.
Add a few shovels of soil and gently firm it with your foot.
Fill the partially filled planting hole with water. Let it drain and then repeat. This will help ensure there are no air holes and the roots are in good contact with the soil.
Back fill the hole the rest of the way with soil.
Use your hands to make a ridge of soil around the outside of the planting hole to catch rainwater.
Place a hose set at a slow trickle near the main stem of the rose. Leave it there for 30 to 60 minutes to thoroughly water the newly transplanted rose.
Apply a 3- to 6-inch layer of mulch. Use wood chips, shredded bark, landscaping gravel, hay or straw. This will control weeds and conserve soil moisture.