Bonsai aesthetics are the aesthetic goals and characteristics of the Japanese tradition in the art of growing a miniature tree in a container. Many Japanese cultural characteristics, particularly the influence of Zen Buddhism and the expression of wabi or sabi,[1] inform the bonsai tradition in that culture. As well, a lengthy catalog of conventional tree shapes and styles helps provide cohesion to the Japanese styling tradition. A number of other cultures around the globe have adopted the Japanese approach to bonsai, and while some variations have begun to appear, most hew closely to the rules and design philosophies of the Japanese tradition.

The aesthetics of penjing, a Chinese form of container-grown tree, are distinct from those of bonsai and are discussed elsewhere. The aesthetics of saikei, Japanese multi-tree landscapes in a container, are also distinct and are not described in this article.

Over centuries of practice, the Japanese bonsai aesthetic has encoded some important methods and aesthetic guidelines. Like the type of aesthetic rules that govern, for example, Western common practice period music, bonsai’s guidelines help practitioners work within an established tradition with some assurance of success. Guidelines alone do not guarantee a successful result. Nevertheless, these design rules can rarely be broken without reducing the impact of the bonsai specimen.