Methodical and artistic pruning is what sets bonsai trees apart from other types of trees. Though there is no need to be fearful when it comes to pruning bonsai trees, putting some thought into the overall design of the tree and being prepared with the proper materials is a step in the right direction.
The important thing to remember is that although careful thought is required, trees do grow, so even if mistakes are made with pruning, they can be overcome with time.
When it comes to pruning bonsai trees, most people think of pruning branches. Though pruning branches is what shapes bonsai trees and make the trees works of art, it's important to also prune the roots.
To prune the roots, use a root hook to dislodge soil and to untangle the roots. Prune the longer roots and any roots that have grown downward.
Pruning should be done when sap is not rising in the tree. Therefore, it is ideal to prune during the dormant season. The dormant season varies from species to species. For instance, pine trees are dormant in the autumn, junipers are dormant in early spring or winter, and most deciduous trees should be pruned late winter or early spring.
Prune every branch that is in the front of the bottom third of the tree. This makes a portion of the trunk visible, which is part of the overall beauty of the tree.
Prune branches that are opposite each other. The longest branch should be pruned to be the same size as the branch from which it is directly across.
Cuts on bonsai trees can be sealed with tree paint that is tar based. Tar-based paints work especially well on deciduous trees. In a pinch, petroleum jelly can be used in place of tar-based paint. Grafting wax works well on evergreen trees and Japanese cut-wood paste works well on all types of bonsai trees.