Tree shaping (also known by several other alternative names) uses living trees and other woody plants as the medium to create structures and art. There are a few different methods used by the various artists to shape their trees, which share a common heritage with other artistic horticultural and agricultural practices, such as pleaching, bonsai, espalier, and topiary, and employing some similar techniques. Most artists use grafting to deliberately induce the inosculation of living trunks, branches, and roots, into artistic designs or functional structures.
Tree shaping has been practiced for at least several hundred years, as demonstrated by the living root bridges built and maintained by the Khasi people of India. Early 20th-century practitioners and artisans included banker John Krubsack, Axel Erlandson with his famous circus trees, and landscape engineer Arthur Wiechula. Several contemporary designers also produce tree-shaping projects.
Some species of trees exhibit a botanical phenomenon known as inosculation (or self-grafting); whether among parts of a single tree or between two or more individual specimens of the same (or very similar) species. Trees exhibiting this behavior are called inosculate trees.
The living root bridges of Cherrapunji, Laitkynsew, and Nongriat, in the present-day Meghalaya state of northeast India are examples of tree shaping. These suspension bridges are handmade from the aerial roots of living banyan fig trees, such as the rubber tree. The pliable tree roots are gradually shaped to grow across a gap, weaving in sticks, stones, and other inclusions, until they take root on the other side. This process can take up to fifteen years to complete. There are specimens spanning over 100 feet, some can hold up to the weight of 50 people. The useful lifespan of the bridges, once complete, is thought to be 500–600 years. They are naturally self-renewing and self-strengthening as the component roots grow thicker.
Living trees were used to create garden houses in the Middle East, a practice which later spread to Europe.