The recommended times to transplant roses are spring and fall, as the rose is emerging from dormancy or preparing to enter dormancy. However, if you need to move a rose in July, the middle of the growing season, it is possible to make a successful transplant if you help the rose get through transplant shock.
Make Preparations Before Transplanting
Prepare the rose bush you want to transplant. Seven to 10 days before you will transplant, cut around the rose bush in a circle about 2 feet in diameter. Use a shovel to cut, and dig straight down into the soil all the way around the rose bush, severing long roots. Do not dig under the bush at this time.
Water the rose bush well after making the cuts. Allow the rose bush to rest until you are ready to move it. The rose will develop new feeder roots during this time, which will help it acclimate to its new home.
Water the rose thoroughly each day for two days before you transplant it.
Prepare the planting hole the day you will transplant so it is ready to receive the rose bush. Till or dig the hole 15 inches deep and as wide as necessary to accommodate the rose you will transplant.
Remove the soil from the hole, and mix in compost. Make a mound of soil/compost in the center of the planting hole.
Transplant the Rose
Spread a small tarp or piece of burlap next to the rose you will transplant. Loosen the rose bush from its current site with a shovel. Keep as much soil as possible with the root ball. Lift the rose and its root ball onto the tarp. Wrap the tarp around the rose, and move it beside the prepared planting hole.
Unwrap the root ball, and set the rose bush into the prepared hole. Center it on the soil mound, and spread the roots evenly around the mound. Fill the hole firmly with the soil/compost mix until it is about half full. Water well, and allow the water to seep away.
Finish filling the hole with soil. Keep the graft of the rose above the soil line. Pack the soil firmly around the roots to avoid any air pockets. Water the rose again.
Prune back all of the stems and canes to at least half. This reduces the amount of top growth the rose will need to try to support, so energy can be directed to root development.
Water the transplanted rose deeply throughout the rest of the summer. Pay special attention during hot, dry weather.