Transplant shock occurs when plants adversely respond to being moved from one place to another.
When moving a plant, do your best to avoid disturbing the root, even resisting the urge to shake dirt off the roots. Keep the root ball wet throughout transplanting, too, as roots that dry out are more susceptible to damage than those that remain moist.
Transplant shock is less likely to occur if most of the roots are moved along with the plant, so try to dig up as many of the roots as possible before picking up the plant and moving it. Water also can help prevent transplant shock by helping the plant acclimate to its new location, so remember to water the plant after it has been moved.