Formal Upright Style
In order to train a bonsai to grow in a style like formal upright, you must raise and cultivate it in perfect conditions. The essential aspect of the formal upright style is having a perfect straight trunk, which tapers from the base to the top in a natural, even manner. No matter what direction the tree is viewed from, this style should appear to have symmetrically spaced branches which are naturally balanced. The formal upright is one of the more demanding styles.
Some great tree varieties to try and train in the formal upright style include pines, junipers and spruces.
You need to make sure that you can see approximately one third of the trunk when viewed from the front in order to create a true formal upright style. This can be as viewed cumulatively, through the arrangement of the branches, or from the base of the bonsai to its first branch.
There should be a distinct natural pattern with the general placement of the branches. The longest branch should be the one closest to the base, which is usually trained and trimmed to a length about one third the height of the bonsai. Almost in a right angle to the tree’s trunk, this will be the “heaviest” branch.
The branch directly above this is grown in the opposite direction from the first branch. The branches are trained into a tapering cone-like shape as the structure of the bonsai ascends.
The mass of needles or leaves that adorns the top of the bonsai is full and thick, expanding out so that, looking down from above the tree, one would find it difficult to make out the internal structure of the branches.
In an effort to give the appearance of “looking at the viewer”, the tip of a formal upright style bonsai leans forward with a slight curve. It is not necessary for the tree to be perfectly symmetrical, as some species will call for you to alternate the branches on each side as they ascend.
There is always a very distinctive tapered characteristic to the trunk and branches of a bonsai in the formal upright style. Every new year, one prunes the trunk or branch by cutting off the growing tip and reforming the apex by wiring a new branch into position to maintain the all-important taper. While training a bonsai in the formal upright style can be somewhat difficult, when the taper becomes gracefully prominent as the trunk begins to fully develop, the breath-taking result is worth all the effort.