Bonsai Technique : Air Layering

A slightly more sophisticated technique to propagate Bonsai is air-layering. The principal of layering is to force a tree or branch to form new roots at a certain point by interrupting the stream of nutrients from the existing root system. This means you can use air-layering for several purposes; reducing the length of a trunk, growing a better Nebari (root flare or surface roots) or selecting a branch to be grown as a separate tree.

Time for Air Layering:

Layering should always be done during the spring, when the tree already started growing after its winter rest.

Techniques Involved:

There are two main techniques to air-layer a tree; the tourniquet method and the ring method.

The tourniquet method involves tightly wrapping the trunk/branch with copper wire to block the stream of nutrients partially. When the trunk/branch grows thicker the stream of nutrients will decrease more and more, forcing it to grow new roots just above the wire. This method is used for rather slow growing trees that need more time to grow new roots; these will not survive the more aggressive ring method.

The ring method involves cutting away a ring of bark at the point on the trunk/branch where you would like new roots to grow. The portion above the ring will have to grow roots immediately in order to survive. The ring should be wide enough to prevent the tree from bridging the gap.

The Tourniquet Method

1. Wrap a piece of copper wire all the way around the trunk/branch right at the point where you like new roots to grow. The wire should cut about halfway into the bark; the thicker the trunk/branch the thicker the wire should be.

2. Dust some rooting hormone (available at Bonsai shops) around the ‘wound’ and now wrap a good quantity of moss around the wound, covering it with some plastic.

The Ring Method

1. Use a sharp knife to cut two parallel slits at least 2 times the diameter of the branch around the circumference of the branch.

2. Now remove the ring of bark between these two cuts right till the ‘shiny’ hardwood.

3. Make sure the ring is wide enough so the tree will not be able to gap the wound; also make sure you have removed the bark all the way to the hard wood; the tree will not start growing roots unless it has no other choice.

4. Dust some rooting hormone (available at Bonsai shops) around the ‘wound’ and now wrap a good quantity of moss around the wound, covering it with some plastic.

After Care

The moss should be kept moist at all times. After about one to three months roots should be growing in the moss. When the bag is filled with new roots carefully cut the layer just underneath the new roots. Do not try to remove the moss or sort the root spread; simply plant it in akadama, fine gravel and potting compost mixed together in a ratio of ½ to ¼ to ¼. Keep the tree protected from low temperatures and wind; a greenhouse or coldframe can be very useful. Leave the tree untouched until the next spring, when it can be trained for the first time. Small quantities of fertilizer can be used during the first summer.

Bonsai Styles : The Basic Five Styles

Styles can be grouped based on different criteria, such as the trunk orientation or the number of trunks in the bonsai specimen. Some of the major style groupings include:

Trunk orientation:

A frequently used set of styles describe the orientation of the bonsai tree's main trunk. Different terms are used for a tree with its apex directly over the center of the trunk's entry into the soil (these are the upright styles, including chokkan and moyogi), slightly to the side of that center (e.g., sho-shakan) , deeply inclined to one side (e.g., chu-shakkan and dai-shakkan), and inclined below the point at which the trunk of the bonsai enters the soil (the cascade or kengai styles).

Trunk and bark surface:

A number of styles describe the trunk shape and bark finish. For example, a bonsai with a twisted trunk is nebikan, and one with a vertical split or hollows is sabakan. The deadwood bonsai styles identify trees with prominent dead branches or trunk scarring.

Trunk and root placement:

Although most bonsai trees are planted directly into the soil, there are styles describing trees planted on rock. For example, the root-over rock style is deshojo, and the style in which trees are rooted wholly within (atop or on the sides of) a large rock is ishizuki.

Multiple trunks

While the majority of bonsai specimens feature a single tree, there are well-established style categories for specimens with multiple trunks. Within these styles, a bonsai can be classified by number of trunks alone (e.g., sokan for a double trunk from a single root, soju for two separate trees, sambon-yose for three trees, and so on). The configuration of the trunks can also be described by specific styles, including raft (ikadabuji) and sinuous (netsunagari) styles for multiple trees growing from a connected root, and the general term yose-ue for multiple unconnected trees in large number.

These terms are not mutually exclusive, and a single bonsai specimen can exhibit more than one style characteristic. When a bonsai specimen falls into multiple style categories, the common practice is to describe it by the dominant or most striking characteristic. For example, an informal upright tree with prominent areas of missing bark and trunk scarring will be described as a sharimiki rather than a moyogi.

Five Basic Styles

Cascade Style (Kengai)

Cascade style represents a tree growing on a cliff with branches flowing down (cascading) past the base of the tree. This style requires the tree to be grown in a pot that is placed on an elevated stand since the tree's branches extend past the base of the container. This style can be successfully achieved with junipers, yews, pines and other confer bonsai. This style takes a lot of patience and dedication as the tree will naturally try to grow upwards.

Formal Upright Style (Chokkan)

This style requires the tree to grow in a perfectly straight line upwards with a vertical taper where the base is visibly wider than the top. There should also be a visible nebari to complete the visual effect of a tree in nature that grows in open flat ground, without competition from other trees, and protected from strong winds. This style represents maturity, perfection, and and timeless quality.

Informal Upright Style (Moyogi)

Informal upright trees grow straight up but with delicate curves in the trunk (usually two or three). The first curve starts at the trunk which tilts at an angle. The remaining curves are spread out throughout the rest of the trunk. This is an ideal style for beginners. Trees well suited for the style include most species of trees, but specifically deciduous trees, flowering trees, maples, elms, and quince.

Semi-cascade Style (Han Kengai)

This style is very similar to the cascade style. The difference is that the decending tree trunk doesn’t normally go any lower than the base of the pot allowing the tree to be displayed on a flat table instead of a tall stand. This style symbolizes trees that grow over flowing water and rivers where the branches almost touch the water. This style can be used for most trees, but works best with junipers, yews, pines and other conifer bonsai.

Slanting Style (Shakan)

Slanting style trees have trunks that slant dramatically to one side as if the tree was forced sideways by some natural phenomenon like strong wind, landslide, or knocked over by a fallen larger tree. This style has branches on both sides of the trunk. This is important to note, because this style is similar to Windswept, which features all the branches on one side.

Fundamentals of Bonsai Styles

Every experienced bonsai enthusiast has his/her own personal idea of what bonsai is to them and what defining factors make them aesthetically appealing.

If a beginner is unable to have the experience of being taught the important principles of bonsai by an expert, he must obtain as much material on bonsai as possible - whether this may be just pictures of trees, discussions on the different styling processes involved or lists of suitable species to use. This mass of information will familiarise them to bonsai and help them gain experience by experimenting on cheap bonsai material. Frequently going to bonsai nurseries and bonsai shows will also allow the beginner to see true bonsai in real life from all sides, opposed to the usual 2D format. This will enable the beginner to see the way bonsai should be displayed and what the end result will be like

The two basic styles of bonsai are the classic (koten) and the informal or 'comic' (bunjin). In the former, the trunk of the tree is wider at the base and tapers off towards the top; it is just the opposite in the 'bunjin', a style more difficult to master.

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.

Understanding Bonsai : The Basics

Sources of Bonsai Material 

Bonsai involves a long-term cultivation of small trees in containers. Trees are difficult to cultivate in containers, which restrict root growth, nutrition uptake, and resources for transpiration (primarily soil moisture). In addition to the root constraints of containers, bonsai trunks, branches, and foliage are extensively shaped and manipulated to meet aesthetic goals. Specialized tools and techniques are used to protect the health and vigor of the subject tree. Over time, the artistic manipulation of small trees in containers has led to a number of cultivation and care approaches that successfully meet the practical and the artistic requirements of bonsai and similar traditions.

All bonsai start with a specimen of source material, a plant that the grower wishes to train into bonsai form. Bonsai practice is an unusual form of plant cultivation in that growth from seeds is rarely used to obtain source material. To display the characteristic aged appearance of a bonsai within a reasonable time, the source plant is often partially-grown or mature stock. A specimen may be selected specifically for bonsai aesthetic characteristics it already possesses, such as great natural age for a specimen collected in the wild, or a tapered, scar-free trunk from a nursery specimen. Alternatively, it may be selected for non-aesthetic reasons, such as known hardiness for the grower's local climate or low cost.

Bonsai can be created from nearly any perennial woody-stemmed tree or shrub species which produces true branches and remains small through pot confinement with crown and root pruning. Some species are popular as bonsai material because they have characteristics, such as small leaves or needles, which make them appropriate for the compact visual scope of bonsai. Bonsai cultivation techniques are different from other tree cultivation techniques.

Bonsai - A Millenia Old Art

In Japanese, bonsai can be literally translated as 'tray planting' but since originating in Asia, so many centuries ago - it has developed into a whole new form. To begin with, the tree and the pot form a single harmonious unit where the shape, texture and color of one, compliments the other. Then the tree must be shaped. It is not enough just to plant a tree in a pot and allow nature to take its course - the result would look nothing like a tree and would look very short-lived. Every branch and twig of a bonsai is shaped or eliminated until the chosen image is achieved. From then on, the image is maintained and improved by a constant regime of pruning and trimming.

It is the art of dwarfing trees or plants and developing them into an aesthetically appealing shape by growing, pruning and training them in containers according to prescribed techniques.