While most people prefer not to transplant rose bushes that have successfully grown in one spot, sometimes it does become necessary. Perhaps the person is moving and doesn't want to leave the bush behind, or maybe some changes in landscaping affect how well the bush does. Whatever the reason, transplanting can be successful if done correctly. All it takes is some knowledge, advance preparation and a commitment to achieve a successful move.
Prepare the area where the rose bush will be transplanted. Properly aerate the soil and prepare a hole that is large enough for the bush but no more than 2 inches wider or deeper than the root ball of the bush to be transplanted.
Mix some potting soil in with the natural soil of the area where the bush will be replanted. Add rose food and/or Miracle Grow into the soil if desired.
Water the area before the transplant is made.
Allow room in the surrounding area for the bush to to grow. Don't transplant it too close to another bush or plant. Knockout roses grow rapidly and require lots of space.
Transplant before the bush it is too firmly entrenched and rooted in the ground in the original location. As a rule, all plants transplant better when they are still young.
Move the plant during late winter or early spring while it is still in the dormant stage. Moving the bush during the height of its growing season is just asking for trouble. Allow between 8 and 12 weeks for the plant to bloom.
Prune the rose bush back before transplanting it. Give it a few weeks between the pruning and transplant, if possible. Also make certain that pruning takes place before winter begins to set in, or a difficult season could end up destroying the bush. Prune them back between 9 inches and 1 foot. This will keep the bush well balanced.
Dig up as much of the soil surrounding the bush to be transplanted as possible. This will help to keep the root system intact and will prevent major shock to the bush.
Keep the bush's root system damp. Cover the roots with cloth that has been dampened, but don't wrap them too tightly.
Transplant the bush as quickly as possible in order to ensure the health of the plant. If it cannot be transplanted immediately, store it in a cool, damp place until the transplant can take place.