Marshall gave a talk on group planting
A group means 2 or more trees, up to about 9. Human eyes can absorb a visual number up to 8 or 9 (then your mind just goes “many”). More than 9 trees and it’s considered a forest. The Japanese word for group or forest is the same – Yose-ue. Marshall surmises it’s a recent style, possibly originating in Japan. Clump style implies root connection or intertwinement.
Rocks used in a group or forest planting – imply a landscape. The outline of the group should be that of a single tree (or the triangle shape). It’s not so important in a forest planting to have the triangle shape.
Perspective in group/forest plantings is crucial. Each tree has an importance within the overall design, but it is the overall design which has pre-eminence.
Groups with an even number of trees i.e. 4, 6, or 8 are not encouraged however having an odd number of trees is not as important as the overall balance of the composition. Using cuttings are usually better than seedlings for uniformity of growth pattern. Groups tend to be planted in shallow pots or on slabs.
Before creating your own group/forest planting remember to do lots of research – study groups created by other bonsai artists, look at photos, read books. Use of templates when composing your group is ideal especially when you’re just beginning. Place your primary trees higher on undulations, the secondary or tertiary trees further down-slope.
Remember to get all the ingredients together before starting; slab, compost, lots of tie-wires, rocks (which, if used, should be buried ½ to ⅔ deep). Remember to take photos of all stages of the planting.