The root system should be pruned gradually, reducing the root system over a period of years. Prune roots at the same time that you prune the shoots so that the bonsai does not become root bound. The surface roots should be left intact. Wiring is next and it is this, together with the bending of the branches that makes the art unique. Wiring is done after the tree has been pruned to its essential branches.
Copper wire is flexible and is usually used for wiring.
Evergreen trees should only be wired during their dormancy so that the new growth is not damaged. Deciduous trees should be wired during their growing season. Begin wiring and shaping at the lowers part of the tree and work up. Don't wrap wire tightly since it could girdle branches and trunk. After wiring, the plant is shaped by hand by gradually bending the trunk and main branches in the desired position.