by George Buehler

Over the next few months, we will examine the various bonsai styles - detailing a few each month. Most authors list five "classical" or better yet, the five basic bonsai styles as:

There are also a substantial number of currently accepted styles, but the five classical styles form the basis from which all the other styles are derived. When we study examples of bonsai grown in each of the basic styles, it doesn't take long to realize that the main distinguishing feature between these styles is the physical configuration of the trunk.

How did the various styles come about? They reflect the observations of natural trees and are only a suggestion of reality rather than a mirror image of natural trees. Some of the "rules" for various styles are pointed toward giving the tree an aged appearance.

In John Naka's Bonsai Techniques I (page 123-124), he lists styles in a somewhat different manner. His list comprises 16 main styles with 26 sub styles. Generally, his main category is for upright trees, cascades, and then various other forms such as double trunks, group plantings, etc. His sub group of upright trees contains, the formal upright, informal upright, and slanting, along with others. We will not sub-divide the categories, suffice to say that there can be combined forms of the various styles.

It seems that bonsai enthusiasts have tried to reclassify the styles and the many sub-divisions into which plants can be trained. Once an understanding of the principles behind the various bonsai styles is gained, it will be easy to assess a tree's potential for a suitable style. Having said that, everyone must understand that sometimes a tree just doesn't conform to a certain style and that it may be a combined form (i.e. a slanting informal upright for instance). That doesn't mean that this should be a new style, it just means that the tree looks better to the stylist in the combined style.

Some trees look better styled in a certain fashion. For instance conifers don't naturally grow in the broom style and few, if any deciduous trees occur in the formal upright style. However, conifers are very suitable for both formal and informal uprights. Deciduous trees are very well suited for informal uprights, slanting, as well as a number of other styles.

Harry Harington in his Bonsai4Me website has an article Styling; the Basic Forms of Bonsai. In the article he makes a distinction between the form and the style of a bonsai. He states: "The form describes the basic shape of the tree as defined by trunk, the style describes the way in which the tree has been styled (for instance windswept, near or far away from the viewer, naturalistic or abstract)". This distinction was put forth by a noted German bonsai artist Walter Pall. To me, this seems like just semantics. In this article, we use the term form and style interchangeable.

When we look at bonsai styles, we must realize that no two bonsai will ever be the same even if shaped by the same person. This is due in part to each starting specimen not having the same branching or trunk structure as well as how the bonsai stylist perceives the tree. However, if two elms, styled by the same artist in an informal upright style, are examined, we find that certain characteristics are evident in both trees. For instance, both may have the first bend at the same height or the branches may be bent in the same form. The "rules" of the informal upright are followed, but the bonsai artist has his own way of styling a tree. We can classify this individual styling as a "signature" of the artist.

It is also evident that trees styled in various parts of the world take on characteristics of that region. This is more than likely due to the way that trees grow in their area or to environmental constraints the trees are exposed to. It can also be due to the cultural aesthetics of a region. This doesn't mean that an informal upright styled in Germany doesn't follow the same guidelines as an informal upright styled in the US. The underlining guidelines are the same, but the individualism is different.

When deciding on a suitable style for a tree, don't settle on the most obvious case. As the tree is examined, it may appear that it is only suited for an informal upright. However, turning the tree or tilting it may show that it fits more into a slanting style or a windswept. Keep an open mind and think about the many possibilities before the shaping process is begun. There is rarely only one choice for a particular tree, and usually there are many possibilities that will yield an acceptable result.

Having laid the groundwork, we will start with the basic styles, the "rules" to follow and list some of the species that can be used for these styles.

FORMAL UPRIGHT - CHOKKAN

IN NATURE

A tree that has a lifetime of ideal environmental conditions without any interference from nearby trees or strong winds usually grows in a straight line. The most important thing to notice for this style is that the trunk is perfectly straight with a natural taper from the base to the apex. All branches are spaced so that they are symmetrically balanced when viewed from any direction. Generally, in nature, only conifers will grow in this form, but other species can exhibit this form if there are no other trees or structures nearby. This form can be found in rural farmland areas, open spaces in parks and in some large acreage landscapes. This style exhibits a feeling of dominance or strength.

IN BONSAI

A formal upright in bonsai is both the easiest and the most difficult style to produce. The "rules" for this tree is that the trunk must be perfectly straight from the base to the apex with all the branches radiating out in a symmetrical pattern. The ramrod straight trunk is perhaps the most difficult feature to find in nursery stock. If this style is desired, it probably is best to start with a seedling when it is most pliable and can be wired or staked up to produce the perfectly straight trunk. However, even if a straight trunk is found or produced, the position and distribution of the branches is fairly critical.

One method of obtaining a large trunk bonsai is to plant a tree in the ground and allow it to grow for several years then cut it down (sometimes called a trunk chop). Under normal circumstances this trunk chop method will not work to form a formal upright style. About the only way this method will work is, after the trunk chop, to form a jin at the top of the tree which then becomes the new apex. Depending on the size of the remaining trunk, there may be a need to carve out some of the trunk to give the impression of a uniform taper. However, in general this trunk chop method should only be attempted by skilled bonsai artist since it will be very difficult to maintain the needed uniform taper.

The branches should also be uniformly distributed around the trunk with the first branch being the most prominent and placed at about one third to one half of the tree's height. This branch can be either on the left or right side of the trunk.

The second branch directly opposes the first branch and is higher on the trunk than the first branch. Going up the tree, the remaining branches uniformly taper in a cone like form. All the branches will be mainly horizontal or slightly drooping as if weighed down by snow in winter.

The back branches on trees in this style are shorter than the side branches. This helps create a feeling of perspective and depth. In addition, going up the trunk, the distance between the branches should become shorter.

The top of the bonsai is usually very thick with foliage. Generally, the foliage mass at the top is so full that it is difficult to see the internal structure of the tree. The apex, of course, should be directly above the trunk base, but it is acceptable to have a slight curve so that the apex leans toward the viewer.

Because there is no lean or curve in the trunk, the weight of the tree is well balanced and it is fairly equally affected by the pull of gravity on all sides. Therefore, the surface roots should spread out evenly around the trunk buttress since this creates an image of great strength and stability.

Quite often in natural settings, a large root occurs under a heavy branch. Therefore, to propagate the dominance of this style, the bonsai artist should strive for a thick root under the number 1 main branch.

The proper height of a tree in this style should be six to eight times the diameter of the trunk at its base just above the nebari.

RECOMMENDED SPECIES

As previously mentioned, conifers are naturally suited to this style. Larches, Junipers, Pines, Cryptomeria, yews, and Spruces are all suitable species. Maples can also be used, but they are generally very difficult to train into this style. Species such as the fruiting varieties or those that are naturally informal, such as boxwoods, or azaleas are not suitable for formal uprights. Generally, deciduous species are unsuitable as formal uprights.

RECOMMENDED POTS

Trees with this style are normally planted in straight corner rectangular pots. The tree should be planted about 2/3 away from one of the ends. As usual, the tree should be planted slightly behind the center line of the pot. Some bonsai enthusiasts use oval or rectangular pots for those trees that have thinner trunks.

The depth of the container should be approximately the same as the width of the trunk at its base. To give a more massive appearance, a pot depth slightly shorter than the width of the trunk can be utilized.

INFORMAL UPRIGHT - MOYOGI

IN NATURE

This style is modeled after trees which grow in less than ideal environmental conditions on lower slopes of mountains or at the margins of forests. Due to its close proximity to other trees that inhibit light, nutrient availability, and growing space, and because of varying wind conditions, the trunks do not grow straight and tall. Normally the trunk has one or more bends, many time resembling an 'S' shape, although it can have any number of bends depending on the age, growth conditions or location of the tree. Although the trunk bends, it generally grows upwards and not in a horizontal position.

IN BONSAI

This form is the most common style used in bonsai because the guidelines for shaping do not have to be followed rigidly, and consequently, this allows more scope for choice of tree and for the individual preferences of the person styling the bonsai.

In a bonsai, the trunk bends either to the left or right but never toward or away from the viewer. The bends can be slight, sharp, exaggerated or soft. The trunk tapers as in the formal upright but may not be completely uniform.

The surface root distribution is very similar to the formal upright - having an even distribution of surface roots around the trunk. However, if the trunk bends drastically to one side, there generally is a corresponding heavy surface root. Like the bends in the trunk, the frontward position should be clear of heavy surface roots.

The first branch should be on the outside of a curve. Ideally, the first branch should be on the outside of the first major bend in the trunk; however, this is not always possible. It is not acceptable to have branches growing from the inside of a trunk curve. In nature, when a tree has bends in the trunk, the tree will try to balance itself by growing in the opposite direction of a heavy branch. In addition, trees put out foliage where they can get the most sunlight, and this would be the outer bend of the trunk. This doesn't mean that the branch has to grow on the 'exact' outside of the curve of the trunk, but it should be as close as possible. If the branch is slightly before of after the bend, it is often possible to wire the branch so that it appears to be coming from the outer edge of the curve.

In styling an informal upright, one has to be cautious that the tree doesn't take on a two dimensional appearance. By that we mean there should be branches radiating out from the trunk (except from the inside of a curve) to give the impression of fullness of the tree. This is especially important toward the top of the tree.

The apex is very full and always above the base of the tree (if the apex is not above the base, the style would be considered a slanting style).

It should be remembered that, even though this style can have many twists and bends, the overall shape of the tree should be triangular.

The Informal Upright style is an excellent one for beginners to start on their practical shaping experience.

RECOMMENDED SPECIES

Almost any species of plant is suitable for this style, especially maples, flowering trees, and conifers. Nursery stock is readily available, especially the conifers. Junipers, pines, yews, boxwoods are all easily formed into the informal upright style.

RECOMMENDED POTS

The informal upright looks best in oval or rectangular pots, planting them 2/3 away from one end and slightly behind center of the short side. The length of the pot should be about 2/3 the length of the height of the tree. The pot depth depends somewhat on the overall look of the tree. A thick stocky tree with minor bends looks best in a deeper pot. A thin tree with major bends would look better in a more shallow pot.

SLANTING - SHAKAN

IN NATURE

In this form the trunk, which can be either straight or curved, slants as though growing toward the light or as though exposed to strong winds. It also could be growing close to older more dominant trees or buildings, causing it to search for light. Soil movement, either through erosion or landslides may also cause the tree to grow in this form. The roots on the exposed side are strong and dominant, while the roots on the leaning side are short and compressed. In both the formal upright and the informal upright, the heaviest exposed root is normally under the densest or largest branch. However in the slanting style, as the tree leans further, gravity pulls more on the weight of the tree, especially older more mature trees, causing the tree to develop stronger more dense roots on the exposed side, not necessarily under the most dominant branch. This form is quite often seen on mountainsides.

This form differs from the windswept in that it has branches radiating out from all sides. Branches on the sheltered side of the trunk can be lower than their counterparts on the other side. Branches on the exposed side should also 'appear' stronger or larger than those on the protected side, since those branches on the protected side would be shaded by the foliage mass on the exposed side.

IN BONSAI

This style can bear a similar appearance to the informal upright. One of the main distinctions is that the apex is not directly over the base of the bonsai. This form can be styled at almost any growth stage of the tree by simple wiring or by planting the tree in a bonsai (or grow) pot at the desired angle. The tree may slant to either the left or right but never away or toward the front. This style can be sub classified as either formal (straight trunk) or informal (have well balanced curves). The angle can be anywhere between 10 to 45 degrees.

As the angle increases, the tree can look unstable, and therefore the roots on the exposed side should appear much stronger than if the angle is smaller. This will put some limitation on how much angle a more mature tree can be planted unless sufficient root mass is available for styling. A younger tree can be planted at almost any angle since there is a larger opportunity for the development of the strong root mass on the exposed side.

Branches and foliage can be dominant on either side but generally the lushest growth is on the most exposed side. Branches should be horizontal or slightly downward on both sides. However, to show that the tree has been growing in the slanting style for a long period, the branches on the exposed side should exit the trunk in an upward manner before they are shaped to a horizontal position. Likewise on the protected side, the branches should initially be positioned downward then shaped into the horizontal position. This downward/upward curvature also indicates that the tree once grew in the normal vertical position but was somehow affected by the environment and changed to a leaning position.

If the tree has curves in the trunk, as with the informal upright, any branch structure should be growing on the outside of the curve.

RECOMMENDED SPECIES

Almost any species is suitable for a leaning style, and conifers work particularly well.

RECOMMENDED POTS

Pots used in the slanting style are normally rectangular with the lean of the tree in the same direction as the longest length of the rectangle. The tree should be placed in the pot about 1/3 the total distance from the edge of the pot with the leaning part over the balance of the 2/3.

SEMI-CASCADE - HAN-KENGAI

CASCADE - KENGAI

IN NATURE

NOTE: Because the semi-cascade and cascade are so similar, we have combined them into one section. In nature there would be little overall difference - the main difference being where the tree grows and its environmental conditions. However, in bonsai there are a number of differences and we will point out the distinction between the two forms. It should also be noted that these two styles are probably the hardest to get a pleasing balance of aesthetics. Additionally, due to the depth of the pot, soil types need to be carefully chosen so that there is exceptionally good drainage. Otherwise the soil layer in the top of the pot may be dry, while the soil in the bottom is still wet, leading to root problems.

This style is found clinging to rock faces and cliffs of high mountain sides as well as along the walls of steep lowland ravines. In general they show the effects of extremely unfavorable growing conditions, quite often bending, or turning downward and outward as the trunk matures. Often the trees are stunted due to the lack of soil, water and nutrients. Trees growing on cliffs or that overhang water can be considered semi-cascade. Trees growing on mountainsides, where the tip of the trunk is below the point where the root mass would be, can be considered a cascade. In both styles, the trunk is tapered and the foliage mass of the branches grow outward, like they are searching for light.

It should be pointed out that the tree's apex doesn't have to be below the root mass. The first major branch may be the actual cascading feature of the tree, while the foliage above that may be stunted and would be considered the apex of the tree. However in natural settings, trees in these styles may not appear to have an apex due to the unfavorable growing conditions.

Trees in this style in nature often have trunks that undulate as they continue their natural growth stages. Remember that trees have a natural tendency to grow toward the sun, no matter where found. The tree may start its yearly growth toward the sun but be bent downward by the heavy winter snow, then the following year start growing upward again giving a curve to the trunk. Continual strong winds coming down the hillside may bend the tender plants so that they grow in a downward fashion and have small trunk curvatures.

IN BONSAI

Semi-cascade

The tip of the semi-cascade projects over the rim of the container, but does not drop below the base of the pot. Although most authorities state that the tip of the trunk falls below the pot rim, that is not a prerequisite for this style. However, most pictures or diagrams of this style show that either the tip of the trunk or the cascading first branch falls below the upper rim of the pot. The angle at which the trunk bends is also not important but is generally between 45 degrees above to a few degrees below the horizontal. The trunk may have been growing upward before bending toward the horizontal. Both the trunk and the branches in this style bonsai have a strong horizontal tendency. Technically, this style is similar to the slanting style with the additional 'rule' that the first branch or the tip of the trunk fall at or below the pot rim. A major problem in styling this form (and the full cascade) is to keep the tree from looking flat. Since the style is basically horizontal, obtaining a balance between the 'requirements' for horizontalness and preventing the appearance of flatness is critical to the overall aesthetics. To overcome this problem, the cascade should be formed with both vertical and horizontal curvature. This curvature should not be drastic (as in some of the informal uprights) but gentler. The curvature can be more rugged in the semi-cascade style, but care must be taken to avoid having the cascade below the base of the pot.

If the cascade is viewed from above, the cascade portion of the tree should be either parallel to the front of the pot or flowing slightly forward toward the front of the pot.

Placement of the apex is dependent on the aesthetics needed to balance the overall design. It can be on the top of the bend in the trunk or almost anywhere along the length of the cascade. As stated, the main criterion is that it needs to be placed to balance the overall design.

Root masses for this style and the cascade are similar to the leaning style in that the root under the lean of the trunk are compressed and normally short, while those away from the lean need to be thicker and stronger to hold the tree in position.

Cascade

The growing tip of a cascade bonsai reaches below the base of a container giving the impression that the tree is being forced down by the forces of gravity. This style is almost an upside down informal upright. This style needs to give the impression of a tree trying to hang on to the small crevices of a mountainside, imparting a ruggedness of the environment it is growing in.

The cascade should bend slightly toward the rear as it goes over the rim of the pot and downward. This will give depth to the design and soften the flatness. As with the informal upright, the branches should be placed on the outside of the bends in the trunk. It is better to design the bends in the trunk in varying proportions. That is having a downward bend then a backward bend followed by an upward bend (or any order of this). The distance between the bends should be varied to avoid the look of a completely styled tree. Also the distance between the bends, ideally, should shorten as the tip of the tail is approached.

Also remember that the design still must maintain the triangular form. This is much more difficult in the cascade and semi-cascade styles. Placement of the branches and curves need to be well thought out before the actual wiring and trimming are begun. Generally, the triangle will be long and skinny with the point of the triangle at the tail of the cascade.

Roots of the full cascade should be very thick on the side opposite the cascade to visually balance the tree, while those roots under the cascade are thick and stubby.

RECOMMENDED SPECIES

These two styles are suitable for almost any species; the exceptions being those species that have a strong tendency to grow upwards like the oaks, etc. Flowering species, such as cherries, apricots, and cotoneasters make lovely semi- and full-cascades. Junipers and cedars are ideal candidates for both the semi- and full-cascade styles.

RECOMMENDED POTS

Pots used for this style bonsai are tall narrow pots. They can be round, square or hexagonal. Pots used in this style need to be chosen carefully for several reasons. Due to the gravitational pull of the cascading branches, special consideration needs to be given to both the height and weight of the pot. This style often needs additional securing of the pot to prevent the tree from being blown off the bench or stand. Additionally, special consideration needs to be given for the placement within the pot.

The tree should be positioned directly or only slightly off the center of the pot for both the semi- and full-cascade. This of course may have to be adjusted due to the surface root placement. If the tree is planted off center of the pot, the shortest distance to the edge would be under the cascade portion.

Height of the pot can compliment the overall appearance of the tree. Using a very deep pot will contrast the horizontal planes and gives the impression of a rugged style, while a somewhat shallower pot gives the impression of a more delicate appearance. Although there are figured cascade pots, use of this type needs to be chosen carefully so that the pot doesn't detract from the overall appearance but rather compliments the tree.

Full cascade pots tend to be slightly larger and deeper than the semi-cascade pots to allow for the larger root mass on the side opposite the cascade. In nature a full cascade tree would have deep roots to stabilize the tree. The semi-cascade would not have as deep a root mass but it probably would be spread out more. The bonsai artist needs to keep this in mind when placing the tree in a pot.

Additional styles will appear in future issues of this newsletter - ED