When growing high-value timber the trees can be pruned to remove multiple leaders, branches and so on to leave clear wood on a single stem as high as you feel like pruning. But foresters of yore would harvest trees leaving natural features like forks for use in applications suited to these shapes in the timber. In boat keels, for example.
So I could leave some of my trees with forks. One possible use for a section of the harvested tree including a fork is as the legs of a table. But will a fork split unless it is tied/fastened in some way? Could be a bit of a mess if it gave way during a particularly raucous dinner party.
Any rustic furniture makers who could comment?
When's the best time to plant a tree? About 20 years ago. When's the next best time? Today!
It would depend on the size since the larger the trees get, the more bark is included in the crotches (forks). The bark is what makes the crotch wood weak. If you use a wide crotch angle without any noticeable bark inclusion I can't imagine it breaking. Once the wood dries it is stronger than when it is alive.