Twin Trunk

by Lawrence Burgess and Noel Gessler

The twin-trunked style is unique in that it is the only bonsai style that has an even number of trunks. It is easier to grow than the more formal single-trunked styles and presents an interesting challenge. On the minus side, it is less grand and dignified than the single-trunked tree and there is often little choice for positioning the trunks for depth and clarity.

Material for twin-trunked bonsai can be found in two ways. Firstly one may use two trees planted closely together to give the impression of one tree, called SOJU by the Japanese. For this type of planting it is best to use two trees of the same species that combine well and supplement each other in their root and branch systems with regard to structure and vigor. The other way is to find a single tree with a trunk which forks near the ground or a tree with a branch low enough to train as a secondary trunk (SOKAN).


Whentwin-trunk-proportion selecting material for this planting there are a few things to bear in mind. The trunk bases and the heights of the trees should be in proportion. If the trunk girth of the larger tree is three times that of the smaller tree, then the height of the bigger tree should be three times that of the small tree.

When the difference in height and girth of the trees is great it can be likened to a 'mother and son'; with less of a difference the composition can be thought of as 'man and woman' or 'master and scholar'. The interaction of the two trees should give the viewer a feeling of warmth and companionship and not that of protagonists.

It is rare that the two trunk heights are found in the right proportion and it will be necessary to adjust them accordingly. If the heights of both trees must be adjusted, the scars should face inwards or face the same direction. If both cuts face to the outside, branches developing will tend to cross each other and even if they are then wired into the correct positions the result will look unnatural. The tree of greater should almost always be the taller tree as the reverse tends to look unnatural.

When you are deciding on the front of your planting remember that the trunks should be positioned on the diagonal with the smaller trees slightly in front of or behind the larger one, never directly in front of or behind it. Nor should they be placed side by side because this gives you a flat two dimensional effect with no depth.


The division of the trunks should be at the base or ground level (never on the upper part of the trunk) forming an acute angle at the base the letter' V' and never the rounded 'U' shape.

twin-trunk-styleThis can be achieved by allowing two trees to fuse together at the base or by air-layering a tree just below a joint.

As with anything else it is as well to plan your planting before actually starting to shape the tree, by sketching the result you want to achieve and as a reminder of what is desired as the planting develops. it will save a lot of work and heart break later on. Plan your design so that both trunks exhibit similar lines of movement and do not have a haphazard growth pattern, such as alternately diverging and converging because this confuses the viewer and looks unnatural. The only instance where it is accepted for trunks to grow in opposite directions is when one trunk of the planting cascades. Trunks which are allowed to cross each other are an eyesore.

When you plan to have features on the trunk like jins and shari, as with the flow lines of the trunks these features should match on both trunks.


Every branch should be wired with the branches arranged to give snatchy views of the trunk all the way to the top. The branches of conifers are normally lowered while those of deciduous trees are wired horizontally or slightly upward, depending on the natural growing habit of the species. The branch placement of the two trunks should adhere to the same principles as if they were a single-trunked tree, especially if the two trunks are close together.

The lowest branch should be on the smaller trunk and branches on the two trees should never be on the same level, creating a bar-branch effect. Branches of the taller tree should never be placed directly above the apex of the smaller tree as this causes the smaller tree to grow away from it to reach the sun. A better placement would be towards the front or towards the back of the smaller tree. Branches from one trunk should not be allowed to cross the other trunk.


The roots should be neatly arranged as for a single tree, i.e. the surface roots should not be one sided but the roots of both trees should compliment each other and radiate out all around both trunks. As with crossing trunks, roots crossing do not look natural and should be corrected or removed.


twin-trunk-bonsai-treeThe overall outline of both trees should form one scalene triangle, round or egg-shape. Each tree must not form its own individual outline because this clutters the design, competes for attention and confuses the viewer.


  2. DEBORAH R KORESHOFF - BONSAI Its Art, Science, History and Philosophy.
  3. KEN YOSHIRODA - HANDBOOK ON BONSAI-Special techniques.

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Random Bonsai Tip

By limbering or flexing a branch or trunk you gently break the cambium layer loose and the healing process will then increase the diameter of a branch or trunk which is too thin