Dead wood can also appear on a bonsai under cultivation for many reasons, including branch die-back, pest infestation, or disease.
It can be partially or completely removed by the bonsai artist, but doing so may damage the tree's overall shape or the illusion of age.
In bonsai being developed from trees free of dead wood, it may be aesthetically useful to create some deadwood elements to enhance the illusion of age, to hide defects (such as an overlarge or misplaced branch), or to disguise the original trunk after reducing the height of a tree that is too tall.
Removing the active leader distributes vigor to lower branches, which will grow more quickly and help increase trunk diameter, reinforcing the illusion of age.
Bonsai gardeners replicate this hollow as a uro by making a small, irregularly-shaped wound in the trunk .
For example, when removing a branch from a deciduous or broadleaf species, bonsai growers often make a uro to avoid having an ugly wound healing slowly and scarring without control.
Sabamiki is done by stripping bark from the trunk, then drilling or carving out the exposed wood to produce a deep wound.
In tanuki bonsai, a living tree is joined to an interesting piece of deadwood to create a composite in the driftwood style.
The living tree (usually a young juniper, because of the species' vigor, flexibility, and ability to endure harsh shaping) is fixed within the channel using non-reactive nails or screws, wire wrappings, or clamps.
Over time, the young tree grows into the deadwood channel, which disguises the fact that it is a separate entity.
Once firmly in place, the nails, screws, or other affixing devices are removed, and the living tree is cultivated and shaped with typical bonsai techniques.
Manual tools like graving chisels, burins, and blades can carve detail into the surface of the jins or shari, since real or simulated wood grain is an important characteristic of deadwood on a bonsai.
Finally, wire brushes and sanding aids remove tool marks and simulate weathering.