One way to get larger bonsai material is to fuse smaller figs together. Basically tieing together several figs that are genetically identical can produce larger trunks. Growing a tree in a larger container or in the ground will produce faster trunk growth but is often not suitable for indoor growers.
Fusion is a useful technique for rare or unusual materials and for adding in branches, roots etc. to a fig that needs these parts.
Bind the trees together with anything that will distribute the compression forces over a wider area to lessen scarring and use a binding material that does not stretch. Allow rampant growth of the materials to speed the fusion.
Marks left from the electrical ties can be reduced by allowing a year or two of un-restrained growth after the ties are removed.
For another article on this topic see http://www.bonsaihunk.us/FusedFig.html
Ficus natalensis only one year since the start of fusing
Lower trunk with fusion remaining to be accomplished with more growth
Ficus virens ‘Thai’ with multiple rooted cuttings pulled together with electrical ties
Close up view of the ties and some marks left from earlier ties that were removed
Ficus natalensis (type two) allowed wild growth to speed the fusion process
Close up of the lower trunk showing nicely fusing trees
The definitive reference work on Ficus
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