There are several different reasons why you may want to transplant a shrub.
When you’re transplanting a shrub, you need to dig around it at the drip line. The drip line is the outside parameter of the leaves on the shrub.
Be careful to get as many roots as you can without making the root ball so heavy that you can’t move it without a Bobcat or track hoe.
Dig deep enough to get all of your major roots. Cut the roots carefully with a sharp shovel. Dig the new hole the same depth as the root ball, but twice the diameter. The sides of the whole should be scarify to allow the roots to penetrate out into the native soil.
When placing the root ball in the new hole, make sure the top of the ball is at grade or slightly above. Backfill with a mix of native soil and amendment. Add two to four plant tabs, depending on the size of the shrub.
Make sure the soil is packed in firmly around the root ball to remove any air pockets. Air pockets can be detrimental to the health of a plant.
Water thoroughly to settle the soil around the root ball and fill in any remaining air pockets. Add additional soil as needed.