Experts and BHG readers answer.
"It's best to move just about any plant when it is dormant--that is, not actively growing and requiring full use of its roots. If the bushes are large and mature, you might consider root pruning them the first year, and transplanting them a year later. Root pruning means slicing into the soil all the way around the plant, preferably as far away from the trunk as practical. This forces the plant to develop a new network of roots within that root zone. Then next year you cut into the same area when removing the plant.
Luke Miller, editor
Garden Ideas & Outdoor Living magazine"