Inarching, also known as approach grafting, is used to join two plants that are otherwise very difficult to join together. The pieces are tied so that each individual piece has roots beneath it and growth above it. Inarching can also be used in pleaching, which is the technique of weaving tree branches into bushes for decorative purposes.
Hilgard, E. W. and W. J. V. Osterhout Agriculture for Schools of the Pacific Slope (New York, NY: The MacMillian Company, 1910)
Courtesy the private collection of Roy Winkelman