Creating bonsai is a living art project. The formal upright bonsai design, known as chokkan in Japanese, is simple enough for a novice to work on, and challenging enough to get bonsai masters. Formal upright bonsai have a straight trunk, with lower branches that stretch farther from the trunk than the higher branches. The divisions grow all over the trunk in this style, and they must form a visible taper with the foundation bigger than the very best. Achieving this contour takes a long time of training.
Getting Started
The tree you start with when creating a formal upright bonsai have to have a straight trunk with healthy branches all the way round the trunk. Conifers work best for this particular design, like “Angelica Blue” juniper (Juniperus chinensis “Angelica Blue”) and “Thunderhead” Japanese black pine (Pinus thunbergii “Thunderhead”). The juniper is hardy in U.S. Department of Agriculture plant hardiness zones 3 through 9, and “Thunderhead” grows in USDA zones 5 through 10. The best time to begin redesigning new bonsai trees is early spring, when they are first beginning to put out new growth. For the first few decades, prune the roots and branches gently to create an overall triangular shape that will lend itself to creating a taper in the formal upright style.
Pruning Branches
One that you have a young bonsai having a straight backward, healthy branches and a general triangular shape, it’s time to move on to the finer points of formal upright style. Training a formal vertical bonsai to have a good taper can take years, but starts with pruning to select the very best forks. Utilize a concave cutter or sharp pruning clippers, sterilized in a solution of 1 part bleach to 3 parts water, to make the cuts. Formal upright styles have an integral branch set lower and extending further from the trunk than the branch opposite. It is the lowest branch on the tree, and extends toward the front of the plan. The next branch is a bit higher, stretching toward the front on the other side of the trunk. The third division goes toward the rear of the tree to give thickness. As you move up the trunk, the purpose is to achieve a balanced design with branches all the way round the trunk. Close to the base of the tree, the divisions will be bigger and more, with more distance between them. On top of the tree, divisions are smaller and closer together. That is what forms the tapering shape.
Enrollment to get a Taper
You may cable bonsai branches at any given time of the year, but it is simplest to wire at the exact same time as pruning. Copper or aluminum wire is best because it is softer and more flexible, but steel cable can be used for tenacious branches. To achieve a good contour on the taper for an official upright, you will need to wire each branch after pruning. Start with the cable anchored in the ground, and wrap the wire around the trunk until you arrive at the branch you want to train. As you cable, keep the cable turns about 1/4 inch apart on the divisions, and do not pull the cable tight enough to pinch the bark. Once the divisions are wired, then bend the lowest key branch gradually and gently into a slight downward slope. Then, bend each other branch in the design in order that their angles match the angle of the crucial branch. For young, growing trees, then take the cable off after a year, and re-wire if necessary.
Trimming the Taper
The youngest branches on a bonsai tree are briefer than the older ones close to the foundation, therefore a taper will naturally start appearing as you prune to choose the very best forks and cable all the branches so they slope at the exact same angle. You will need to prune diligently to maintain the taper of a formal upright style. Each spring, trim the roots and branches of the tree at the exact same time, removing about the exact same proportion of origins as you do divisions. Snip off the ends of the branches to maintain the very best branches shorter than the lower divisions, keeping the tapered style, and re-wire as needed to maintain the desirable branch slope. As the tree grows, new divisions will look close to the top and angle upwards rather than down. These will have to be pruned, thinned and re-wired, following the exact same pattern as previously branches. If several branches grow on the exact same level of the trunk close to the surface, prune them away so only one or two stay. They may create the bonsai taper look fuller in the brief term, but will avoid future overcrowding.