There are occasions when you need to move a tree or shrub from one place to another, or perhaps you want to try your hand at moving a tree from the wild to your landscape. Successful transplanting requires patience and work.
The challenge in transplanting trees and shrubs is to preserve as much of the root system as possible. Small plants and seedlings can usually be moved with little difficulty. Larger specimens with wide spreading root systems requires more planning. For these you need to force the plant to grow more roots closer to the trunk so they can be included when you dug up. Root pruning does this.
Root pruning is done while the tree is dormant, from late Fall to early spring. The simplest way to root prune is to sharpen a flat bladed shovel and make cuts into the soil around the tree. An especially good shovel for this project is a long narrow one called a transplanting spade. Root pruning should be done at the same distance from the plant as you intend to dig up the root ball a year later.
The rule of thumb is to go out from the trunk one foot for each inch of trunk diameter (smaller plants are definitely easier). The severed outside roots will die, and the shortened inner roots will grow new roots closer to the tree. The tree can be dug up one year after root pruning. Before digging the tree, prune back the top growth by at least one third. This will help reduce the workload of the reduced root system. Be ruthless, but try to keep the plant attractive looking.
Digging up the tree is also done during the dormant season when the ground is not overly wet or frozen. Start well out from where you want to form the root ball and work your way in carefully. Leave as much soil on the roots and possible. At the bottom of the tree you may run into a large taproot. Its function is mostly support, so don’t be afraid to cut it, just take as much of it as you can.
Once the root ball is dug, wrap it in burlap to keep it together. Move the plant to its new site and plant it as soon as possible, keeping the root ball moist. Dig a hole large enough so that the root ball fits comfortably. When planting, the shrub should be placed at the same level it was before it was moved. Fill the hole with dry soil and water well when finished.
If the tree is tall you should support it with some form of staking. It takes a full growing season for the plant to become reasonably settled. During that time it should watered often, and mulching will help keep the soil moist. Don’t fertilize the tree the first year.