Living sculpture is any type of sculpture that is created with living, growing grasses, vines, plants or trees. It can be functional and/or ornamental. There are several different types of living sculpture techniques, including topiary (prune plants or train them over frames), sod works (create sculptures using soil and grass or moss), tree shaping (growing designs with living trees) and mowing and crop art (create patterns or pictures with plants or in lawns). Most living sculpture technique requires horticultural skills, such as grafting or pruning, to create the art.