Usually an odd number of trees are used unless there are more than nineteen. The trees should be of different sizes and have the same general characteristics-either all straight trunks or all curved in such a way that they are compatible. Always use the same species for all the trees.
The pot can be oval, rectangular or a free-form slab and should be either larger or smaller than the tallest tree. It can be glazed or unglazed depending upon the plant being used. The depth of the pot should not be deeper than the caliper of the largest tree.
Potting materials are the same as for any other bonsai; soil, screen to cover the drainage holes and wire for the trees and to secure the trees to the pot. When planting on a rock or slab it will be necessary to attach the wire to the rock with epoxy, cement or other means. You will also need muck to build a wall around the planting area in order to hold the soil in place.
If you wish to create a landscape effect you will need some rocks, moss or other small leafed plants.
Preparing the Pot
If you are using a conventional bonsai pot you can attach the tie-down wires through the drainage holes.
Holes can be drilled in mica pots for the wires. Drill the holes where you wish to place each tree, the size of the hole should accommodate a 2mm aluminum wire. One wire wrapped around the trunk is usually sufficient to hold the tree in position.
If a rock slab is being used it will be necessary to attach the wire with quick-set cement or epoxy. First cut pieces of 2mm wire long enough so that it can be bent into hairpins to be used to hold the trees to the rock. Lay them on the rock in the area where you want to plant the tree. After all the wires are in place mix the cement or epoxy and pour it over the u-curve of each wire. After it has cured the wires can be bent into a vertical position ready for planting.
Muck walls should be applied to the rock around the areas that the soil will occupy. Muck can be made with clay, peat, sphagnum moss and some fine bonsai soil, slow release fertilizer can also be added if desired. Mix the ingredients with water to form a stiff workable consistency. After applying the muck it must never be allowed to become completely dry as it will shrink and pull away from the rock. Place a layer of soil in the bottom of the container before planting the trees.
The root ball of all the trees should be reduced so that they will fit in the planting. Tropicals and deciduous trees can be bare-rooted and root-pruned as needed.
Remove unwanted branches and shorten the trunks to conform to the caliper of the trunks. The tallest tree should be taller or shorter than the length of the pot. The height of all the other trees is determined by the diameter of the trunk and should be proportionately taller or shorter.
Wire any trees that need to be wired.
Place all the trees in a row according to their trunk caliper, the largest tree next to the pot. With the base of each tree in a straight line it is easy to determine the height of each tree, shorten as needed.
There are an infinite number of ways to create a forest, therefore you can be as creative as you wish. It is helpful to have a plan before you start to plant your trees but it is not necessary. Study the largest tree to determine the front, keep in mind that all the other trees will have to blend together. The largest tree is planted first and the other trees are arranged around this main tree in the order of their size, the smallest is planted last. The overall silhouette will have a triangular appearance.
Before planting each tree in the pot make sure that the roots have been trimmed so that the adjoining tree will fit. The first tree is placed off-center and must be secured with wire. The second tree is positioned then the third etc. Never place trees in a straight line, any three trees will always form a triangle when viewed from the top. When viewed from the front all the trees should be visible at a normal viewing distance and should appear to be planted at an unequal distance apart. Make sure that all trees are secure in the pot. Sometimes it is possible to anchor two or more trees with the same wire. If you are using a slow release fertilizer briquettes place them around the perimeter of the planting just below the surface of the soil. Add more soil to fill the pot. Hold each tree in position as you work the soil around the roots with a chopstick.
After all the trees are secure in the pot study the overall appearance and make any necessary adjustments. Trim the silhouette to the desired shape and remove any branches that aren=t needed -those that are crossing the trunks in the lower third of the tree. The shortest trees will have the lowest branches, the tallest trees may only have branches in the top third of the tree. If you wish to create a landscape you can add other small leafed plants, use larger plants in front, smaller ones near the back to give the illusion of depth.
If you are using rocks, place them so that the soil appears to have eroded from around the rock. A round shaped rock will have less than half it’s surface exposed.
Contour the soil to have a natural appearance. If you are using moss, contour it to give a natural appearance.
Aftercare is the same as with other bonsai and will depend upon the plant material.
It is usually advisable to allow the planting to develop a strong root system before trimming the trees.