Creating a Forest Bonsai

by Brent Walston

Introduction

From a beginner point of view, this is an excellent early style, if not first tree, because the material involved is inexpensive, and usually readily available. In winter, bare root seedlings for forest plantings can be purchased in bulk for about $.35 to $.50 each. These trees usually come in bundles of 50 to 100. One could share an order with a friend or club members and obtain enough material for several group plantings and specimen trees alike.
Most of these bare root tree seedlings are field grown and will require the removal of the tap root and one year of pre-training prior to use as bonsai. I have described this process in the article on bare root pruning at our website.

Tree Arrangement

I spend a lot time thinking about tree placement to get the most natural looking arrangement, and have come up with some guidelines that I think work. First, it helps to have a concept of the scalene triangle outline used so much in bonsai. This is a triangle that often defines the outline of the foliage canopy. The elements of the triangle are three unequal length sides and no right (90 degree) angles. This will make a triangle which when viewed from the 'front' or main perspective that will have three levels defined by the corners. The points of the triangle can represent the position of elements, either trees in a forest, the three levels of the canopy, or the position of stones in a garden.
This group of three can be also be thought of as a group of two and one. A group of five can be envisioned as a group of three and two, or two groups of two and a group of one. Seeing the placement in groups three, or two and one can help one find pleasing positions for all the trees.
Another guideline I use is to never place a tree on the center line (through the front) or the mid line (that divides the front and back) of the pot. Trees placed in these positions will create a perfect symmetry that does not work as well as dynamic balance. I describe this as taking the visual mystery out of the space. Our eyes are very good at spotting whole number intervals, especial halves and quarters. We can actually do this with a high degree of precision. I think that what we do subconsciously is to dismiss these intervals when we detect them. Spaces that do not fall into easily easily defined intervals have more interest to us and 'move' as our brain tries to define the interval.
Trees should not fall directly behind one another when viewed from the front, and three or more trees should not fall on a single line. They may be placed tightly together at the middle of the pot with a rather large empty perimeter creating a 'knoll' look as found on hilltops, or be distributed in the pot giving more of a forest look.

Creating Perspective

The trees at the edges of the group can be placed leaning slightly outward to create perspective effects. This is almost a 'fish eye' lens image and tends to enhance and enrich the compactness of the forest. It also helps light to penetrate the center. This can be very subtle or exaggerated, each will give a very different look.
If the larger trees are placed in the front and the smaller ones in the back, this will also create perspective, with the view fading away as the eye goes through the forest.
The number one, two, and three trees are very important and must be placed carefully. They should diminish in height and caliper, and be positioned in a group of three. This works most easily if the number two and three trees are placed to the left and right of the number one tree. The remainder of the trees can be similarly small, but reserving the tiniest for the back.

Securing the Trees

Securing trees to the pot can be very challenging. In general, there must be some way of holding the trees in place until the roots knit together as one pad. From a styling perspective, anchoring makes the work a lot easier. For larger trees the general placement can be decided upon before the trees go in the pot and wires expoxyed to the bottom. A loop of wire can hold one root ball, or used to wire the trunks of two trees which will also hold them in place. For smaller pots I wire a large piece of stiff plastic mesh to cover the entire bottom instead of just the drain holes. Before securing it, I tentatively decide where the trees will go and loop wire through the holes to secure the trunks of two trees with one piece of wire.

Exploring Your Options

I find groups of three to be very challenging, for me it is easier to work with larger numbers. Even in small six inch pots I prefer to work with seven trees.
I have seen some very handsome groups where there are massive numbers of trees without clearly defined main trees, but I prefer the above approach. This is merely a matter of taste.
Placing the trees in groups as above should create unequal spaces between the trees for the 'birds to fly through' and often a space or shelter near the center of the pot near the number one tree. This is a resting place for the eye. I position the branches to invite the eye into this space.

Species Influence

Different species can create very different looking group plantings. For example, here I have compared Trident Maple, Acer buergerianum to Chinese Cork Bark Elm, Ulmus parvifolia 'Corticosa'. The example works for most maples and Chinese elms
Tridents, when planted in groves, have a very upright, soaring quality which is very pleasing. They will really give you the feeling of a natural forest mono culture typical of temperate hardwood regions. Getting spaces below the canopy will be very easy because they tend to bud break just below the cut when pruned.
Cork Bark Elm looks best, and is naturally inclined to be a round headed tree. As a grove, I would give them more space so that the character of each tree could develop. This look is typical of the open oak forests of California. The dome of each tree in these natural groves is usually clearly visible, even though they are grouped. The dark green canopies of these oaks against the golden dry grass of late summer is one of my very favorite sights in the whole world, and some day I hope to make a representation of this in bonsai.
The elms treated in this fashion would require larger trunks and shorter trees than Tridents, and more space between the trees to allow for the round headedness. It seems to me that this would be an appropriate situation for a large slab.

And finally

The scalene outline of the foliage is created by the entire canopy of all the trees instead of the main branches and apex of a single specimen bonsai. The highest point, of course, created by the number one tree, and the other two by the farthest left and right trees. To me, it is not too important to have either the left lower than the right or vice versa in a group planting. Many flattened dome outlines are perfectly satisfactory. My favorite view of forests is without the leaves anyway. The intricate branching of so many trees in a small pot is the real treat for me.