Over the years, bonsai enthusiasts have frequently tried to reclassify the styles, and their many sub-divisions into which plants can be trained. Once you understand the principles behind these designs/styles, you will have a reference point from which to assess a tree's potential for bonsai and to decide what style suits it.

If you study very carefully the way trees grow in nature, it is possible to design a realistic bonsai without knowing the names of these styles. You do not need to stick strictly to the precise rules of your chosen style: adapt them to suit a plant's natural habitat.

When you start a bonsai, always remember that you are working with a living plant. Look carefully at its natural characteristics and you may discern within them a suitable style, or styles. All conifers are reasonably unsuitable to the 'broom' style, for example, but are very suitable for all other styles, especially formal and informal upright - to which they are particularly suited. Often you can train a plant into several styles, even if it is basically upright like a beech or elegantly slender like a maple. Even if one style only really suits a particular plant, you still can interpret this in many different ways.

Shrubs like azaleas that are not tree-like in nature have fewer restrictions in the style you choose, but, generally, it is best to base any design on the way a tree grows in nature. People that are still learning the basic principles of bonsai should not try to train a bonsai into a style totally unlike a tree's natural growth pattern, although this is quite possible as you gain more experience.

The Five Main, Commonly Used styles :

The five basic bonsai styles are formal upright, informal upright, slanting or windswept, semi-cascade and cascade. All have their own individual beauty and serenity. I will now attempt to explain the basic principles of each style.

Formal Upright...

A tree with a style such as Formal Upright occurs when it has grown in the open under perfect conditions. The most important requirement for this style is that the trunk should be perfectly straight, tapering naturally and evenly from base to apex. The branches should be symmetrically spaced so that they are balanced when viewed from any direction. It is quite a demanding style to achieve.

Recommended Species : Larches, Junipers, Pines and Spruces are all suitable species. Maples can also be used, but are not as easy to train into such a conformist style. Above all, fruiting or naturally informal trees are not suitable for formal upright

Processes/Techniques Used :

To achieve an effective formal upright, make sure that about one third of the trunk is visible from the front, either from the base to the first branch or cumulatively, as seen through the tracery of its branches. Generally, the placement of branches follows a pattern. The first branch up from the bottom is the longest and in proportion usually is trained to grow to an equivalent to a third of the total height of the tree. This is the 'heaviest' branch almost making a right angle to the trunk. The second branch directly opposes the first branch and is higher on the trunk. As the branch structure ascends, they taper assuming a somewhat cone-like form. The top of the bonsai is usually very thick with foliage - so full and tightly ramified that it is difficult to see its internal structure through the mass of leaves or needles. The tip of this style of bonsai also has a slight curve, to lean forward and effectively 'look at the viewer'. Depending on what species of tree you are using, the whole tree does not have to be symmetrical but rather the branches could ascend by alternating on each side. (I personally prefer this, as the former seems too regimented.)

As mentioned earlier, the branches and trunk of a formal upright bonsai always take on a very distinctive taper. This is achieved by cruelly cutting off the growing tip of the trunk or branch with each new year and wiring a new branch into position to form the apex. This is something quite hard to do, however it produces a stunning result when the trunk starts to mature and the taper starts becoming prominent.

Informal Upright...

In nature, such trees bend or alter their direction away from wind or shade other trees or buildings, or towards light. In an informal upright bonsai the trunk should slightly bend to the right or left - but never towards the viewer. (This applies to all types of bonsai. Neither the trunk or branches should be pointing towards the viewer when the bonsai is viewed from the front.)

Recommended Species : Most species of plants are suitable for this style, mainly the Japanese Maple (Acer palmatum), Trident Maple (Acer buergerianum), Beech, practically all Conifers and other ornamental trees such as the Crab Apple, Cotoneaster and Pomegranite

Processes/Techniques Used :

An informal upright bonsai basically uses the same principles of the formal upright bonsai only that it is informal. The style still requires a tapered trunk, however the trunk direction and branch positioning is more informal and closer to the way a tree would look when exposed to the elements at an early age. The trunk usually takes on an unexpected curve or series of twists and the branches are thus positioned to balance this effect. As with formal upright, the crown of the tree is mainly very full with foliage and despite the informal trunk, is most always located directly above the base of the tree. (This is an attribute of the informal upright style, if not done like this, the tree would be slanting.)

Jin (carved remains of dead or unwanted branches to look like dead and rotting limbs of a tree) is also more appropriate and effective with the informal upright style.

Slanting...

Trees that slant naturally occur a result of buffeting winds or deep shade during early development. Whether curved or straight, the whole trunk leans at a definite angle. The stronger roots grow out on the side, away from the angle of the trunk lean, to support the weight.

Recommended Species : Most species are suitable for this style, as the style does bear similarity to informal upright. Conifers work particularly well

Processes/Techniques Used :

As mentioned before, this style does bear similarity to informal upright. The trunk can be either curved or straight, but must be on an angle to either the right or left (never to the front), with the apex not directly over the base of the bonsai.

This style is quite a simple one that can be achieved by many methods. At an early age, the bonsai can be trained to an angle by means of wiring the trunk until it is in position. Alternatively, the tree can be forced to grow in a slanted style by putting the actual pot on a slant causing the tree to grow abnormally.

With formal upright, informal upright and slanted styles, the number three is significant. The lowest branches are grouped in threes, and this grouping begins one-third of the way up the trunk. The bottom-most three branches almost encircle the trunk, with two branches thrusting forward, one slightly higher than the other. The third branch, emanating from a point between the first two, is set at such an angle as to make the foliage appear lower than the other two. This pattern presents an easy way to tell front from back and sets the tone of the entire composition.

Cascade...

The growing tip of a Cascade bonsai reaches below the base of a container. The trunk has a natural taper and gives the impression of the forces of nature pulling against the forces of gravity. Branches appear to be seeking the light. The winding main trunk is reminiscent of a stream meandering down the side of a mountain.

Recommended Species: Many species are suitable, if they are not strongly upright.

Processes/Techniques Used:

If done right, this style of bonsai can be quite aesthetically pleasing. The trunk which is tapered, grows down below the container and gives the impression of the tree being forced down by the forces of gravity. The tree trunk usually also twists as if to emulate a meandering stream with elegant alternating branches protruding from it.

All that is required to create this style is a tall, narrow pot which will enhance the style and accommodate the cascade and a species of plant that will willingly adopt this style if trained. The main trunk should be wired to spill over and down the edge of the pot, with the main focus on the major bend (forming an upside-down U shape). Emphasis should also be kept on keeping the branches uniform and horizontal to the almost directly vertical trunk. Another major aspect to remember is that both cascade and semi-cascade should be positioned right into the center of the pot, the opposite to what you would do for any other styles.