Japan faced a severe timber shortage by the 15th century, driven by high demand for traditional architecture. To combat dwindling resources, craftsmen developed daisugi, a method of growing multiple trees out of a single trunk. This technique essentially treats large trees like bonsai, creating a platform of vertical stems that grow upward from a central base.

This method produces taruki, a specific type of timber used for tea-house roofs. Unlike standard lumber, these beams are incredibly straight and uniform. The structural properties are impressive; the resulting wood is 200% as dense as standard cedar. Such density makes the material ideal for heavy roofing and typhoon-resistant construction.

Originating in Kyoto, the practice responded to the aesthetic demands of tea masters like Sen-no-rikyu. By forcing trees to grow in a platform shape, foresters maximized yield while minimizing land use. This ancient engineering solution provided high-quality building materials without requiring massive deforestation of the Japanese countryside.