Even if you don't grow your own trees or shrubs from seeds, nursery-grown plants of many species are seedlings. Gardeners who buy such trees have to wait 5-10 years for the first flowers to appear, after the tree has grown quite large. On the other hand, grafted trees usually flower the first year after graftage, often while still in a 1-gallon pot. The reason for this difference is that in a grafted plant, the scion is cut from an old, mature tree. Grafting a plant allows you to select a root system adapted to your climate and soil, or resistant to local pests and diseases.
Some rootstocks produce extreme vigor in the scion.
Others may cause the scion to be dwarfed. A skilled grafter can propagate more species or varieties, often with better success, than could be accomplished by rooting cuttings or air-layers. Because of these advantages, most fruit and nut tree species are commonly grafted, including apples, pears, peaches, plums, cherries, citrus, some grapes, walnuts, pecans, and avocados. Some woody ornamental plants are also commonly grafted, including blue spruce, some magnolias, most roses, gardenias, camellias, and tree peonies. Use a sharp knife.