Known for shape, style and their small size, bonsai trees originated in China. Bonsai trees receive their distinctive shapes two ways, through pruning and wiring. Many novice bonsai growers feel intimidated by the thought of pruning their trees. Though such insecurities may have some merit, it is important to remember that bonsai trees grow and therefore mistakes can work out over time. Careful thought before the actual pruning begins reduces the number of mistakes that require growing out.
Prune your bonsai tree's roots. Although most pruning occurs on the visible portion of the tree, root pruning improves the overall health of the bonsai plant. First, shake all large clumps of dirt off the roots. Use a root hook to untangle and dislodge additional dirt from the roots. Clip off the bottom third of the roots and cut off any damaged roots.
Prune your bonsai tree in the right season. Prune the tree during dormancy, when the sap does not rise. The dormant season varies from species to species. Deciduous trees are dormant from late winter to early spring, juniper trees are dormant between early spring and winter and pine trees are dormant in the fall.
Remove all branches located at the bottom third of your bonsai tree. The trunk adds to the overall design of your bonsai tree; prune enough branches to reveal the bottom part of the tree.
Prune branches across from each other; cut them so they become near equal in size to the branches located across from them. Cut just small amounts off the smaller branches; focus on reducing the size of the larger branches.
Seal cuts on your bonsai tree. Use tar-based paint on deciduous trees. Seal evergreen trees with grafting wax. Specially formulated Japanese wood paste works well on all bonsai tree types. In a pinch, seal cuts with petroleum jelly.