Plant grafting is a propagation technique by which a scion or whip (thin branch or shoot) of one plant is attached to the root stock, and often trunk or main stem, of another plant. Usually the receiving plant is notched or split at the graft site, and the plant being grafted is inserted into that cut; the join is then wrapped with tape or coated with wax or asphalt grafting compound to hold it in place until the two grow together. Fruit trees, vegetables, and ornamental trees and shrubs may all be grafted.
Despite being labor intensive, grafting is commonly undertaken as a means of vegetative propagation of woody plants for any or all of the following reasons:
(1) to impart disease resistance or hardiness, contributed by the rootstock;
(2) My Favourite Reason : to shorten the time taken to first production of flowers or fruits , in some cases by many years;
(3) to dwarf the scion, making both its height and shape more convenient for harvesting fruit, as with apples;
(4) to allow cultivars to retain their desirable leaf, floral, or fruit characters, without the risk of these being lost through sexual reproduction; and
(5) to provide the most economic use of fruit material, in cases where there is some difficulty with stem cuttings producing roots.
Most fruit trees do not reproduce true-to-type from seed. Apple and pear trees of a particular variety can only be reproduced by grafting branches of the desired variety to another tree stock. The fruit of these grafted trees will be identical to the fruit of the original trees. Fruit tree grafting also allows orchardists to control the size of the trees they are growing by their selection of dwarf or full-size root and trunk stock. Ornamental novelty trees can also be created for the home landscape by grafting several fruit varieties onto one trunk stock.
One key advantage of grafting for gardeners and market farmers is the ability to grow delicious heirloom varieties, which lack modern disease resistance, on disease-resistant stock. Grafting to sturdy root and main stem stock also improved the yields of the heirloom tomato varieties where there was not disease pressure, which makes growing unique and interesting tomatoes–even by organic methods–considerably more economically productive for small market growers, and allows home gardeners a wider choice of tomato selections.