grafting, horticultural practice of uniting parts of two plants so that they grow as one. The scion, or cion, the part grafted onto the stock or rooted part, may be a single bud, as in budding, or a cutting that has several buds. The stock may be a whole mature plant, such as an apple tree, or it may be a root (usually of a seedling). The most important reason for grafting is to propagate hybrid plants that do not bear seeds, or plants that do not grow true from seed. It is also used in dwarfing and in tree surgery, to increase the productivity of fruit trees by adding to the number of buds, to adapt a plant to an unfamiliar soil or climate by using the roots of another plant which thrives in that environment, and to combat diseases and pests (e.g., the phylloxera) by using a resistant stock. Grafting does not produce new varieties, since both stock and scion retain their characteristics. Grafting, which was employed in Roman times, is used extensively by nurserymen and other horticulturists. In general, only closely related plants can be grafted successfully. As a rule, the process is begun when the scion is dormant and the stock is just resuming growth. There are many methods of grafting, all of which depend on the closest possible uniting of the cambium layers of both scion and stock.
See R. J. Garner, The Grafter's Handbook (3d ed. 1968).