Digging up a growing tree to replant in a new location--known as transplanting--must be done carefully in order to preserve the root system and ensure that the tree will thrive in its new location. Certain trees, such as eucalyptus, are sturdier and are better able to handle the transplanting process than others. Always research the specific tree before beginning the process to see how likely it is to survive transplanting and to note any tips specific to that variety. Transplants are best done in late autumn after the leaves have finished falling off the trees, or even in winter, but not at extreme temperatures.
Measure the Tree
Young trees, or saplings, are those measuring about 5 to 7 ½ cm around the base of the tree, and are the easiest to transplant. Moving larger trees is much more involved and quickly can become so large in scope that it requires hiring a company or renting large equipment. In general, every 2 ½ cm of trunk diameter requires 25-30 cm of root ball. Take into consideration that the weight of the tree, soil, and attached root ball will be approximately 488 kilogrammes per square meter. Measure the tree diameter at the base, calculate the necessary root ball size, and decide if the project can be done without professional help.
Preparing the Tree for Transplant
Once it has been determined that this is a manageable gardening project, it is time to start preparing the tree and the transplant site. Typically the preparations start in spring for a tree to be ready to move in the fall. Healthy trees are more likely to survive the stress of transplanting, so if the tree is struggling, it will be necessary to spend time nurturing it before moving. Choose a new site with similar soil, sun, and drainage to its current spot and always ensure that there is adequate space to grow. In the spring, begin preparing the roots by using a sharp, flat spade to cut a trench using measurements for the root ball that were determined earlier. The trench should be about 60 cm deep. Continue watering the area as the goal is for the root ball to develop new feeder roots closer to the base of tree. Also water the new tree site to begin loosening the soil. When it is time to move, cut the root ball another 10-15 cm out from the trench to make sure that the new feeder roots are included. Before removing the tree and its root, dig the new hole, making sure the soil is loose and moist enough to allow for continued root growth.
Moving the Tree
An important tip to remember is that air can be very damaging to the roots, so have an adequate piece of burlap ready to wrap the roots if the tree has to go any distance before being brought to its new site. Position it in the hole at about the same height as before, once again focusing on keeping the roots covered in soil and free from air. Cover it with soil and water. After the water has soaked in, water again and add soil as needed to make sure the roots are covered.
Caring for the Tree After Transplanting
Staking the tree can help both young and mature trees as their roots grow and take hold, and are typically best used for the first year. In the first year, avoid fertilising and do not be discouraged if leaves fall off, as they often regrow. It is important to keep the ground moist but not overly saturated. Using a layer of mulch measuring 5 to 7 ½ cm deep can help steady the moisture level and temperature of the roots.