Gardeners may need to transplant evergreens in the home landscape for a variety of reasons. Plants outgrow their current location or overrun nearby ornamental plants during expansion. The act of transplanting an evergreen requires planning to limit the amount of transplant shock experienced by the shrub. Transplant shock occurs when too many feeder roots are left behind in the former location. The gardener should begin preparing the plant for moving in the fall, with physical transplant occurring the following spring.
Schedule root pruning in the fall before the ground becomes too hard to work easily. Root pruning chops off some of the extensive root system of the evergreen without subjecting the plant to immediate transplant. Cutting off lengthy roots encourages the plant to develop new feeder roots closer in to the main root ball. The plant will experience less transplant shock by allowing time for new feeder roots to grow.
Tie up the branches of the evergreen using twine to protect lower branches and to allow working space for the gardener.
Plan the size of the future root ball for the plant. This depends on the overall evergreen size but a general rule is that the proposed root ball should be two-thirds the size of the branch spread of the evergreen. Look at the canopy of the evergreen and the drip line extension point to help you decide where to root prune.
Place the spade shovel 6 inches closer to the main trunk to create the planned root ball. Moving inward will allow feeder roots to develop in an area that won't be harmed during the transplant. Feeder roots will be housed in protective soil away from the edge of the new root ball.
Step down on the shovel to a depth of about 8 to 10 inches. Remove the shovel blade straight out of the ground and repeat this action around the entire tree. Connect each slice into the soil end to end to create a seamless circle around the plant.
Remove the twine holding the branches and wait until spring to transplant to a new location.
Transplanting the Evergreen
Prepare the new location by turning over soil layers to a depth of 12 to 18 inches. Work compost or peat into the soil to increase organic content and dig a hole twice the size of the transplant root ball.
Return to the original planting site and carefully tie up the evergreen branches to limit damage during the move.
Dig around the perimeter of the evergreen 6 inches outward from the original root pruning spade cuts. Carefully remove soil to expose the edge of the root ball. Gradually work the shovel under the evergreen until you can lift the plant free from the soil for transport in the wheelbarrow. Don't hack, chop or slam the shovel roughly against roots during this process. Move the shovel further out to avoid harming roots.
Carefully place the evergreen in the new planting site and check the planting depth. Try to mimic the previous planting depth and conditions as much as possible.
Fill in the planting hole with soil and smooth the garden surface with a rake. Add a protective layer of mulch to promote water retention and to protect roots from the heat of the sun.
Water the newly transplanted evergreen after planting as well as throughout the year. Don't let soil become dry and monitor the plant carefully during times of drought. Water at the base of the evergreen with a low trickle of water or soaker hose to allow water to seep deeply into the soil around the roots.