Most big fruit tree orchards use grafted trees to combine a sturdier trunk and root plant with delicate branches that produce tasty and consistent fruit. A long-dead fruit tree can keep bearing fruit from branches attached to a different trunk. And it is possible to graft several different kinds of fruit branches onto the same tree!
Grafting unites the tissues of two or more plants so that they grow and function as a single plant. One plant in the graft is called the rootstock, selected for its healthy or hardy root system. The other plant or plants, chosen for their fruit, flowers or leaves, are known as scions. You can join a scion to a rootstock in many different ways. In one of the most common techniques, you remove a branch from a plant whose fruit you want to reproduce and cut the broken end of the branch into a V-shape not unlike the reed for a woodwind. Shaving the scion in this way exposes its vascular cambium—a ring of plant tissue full of dividing cells that increase the branch’s girth. Once the scion is ready, you slice lengthwise into a branch on the rootstock—exposing its vascular cambium—and wedge the scion into the cleft. Successful grafting requires placing the vascular cambia of both the rootstock and scion in close contact. Another grafting method involves cutting small pockets between the rootstock’s bark and cambium and slipping scions into those pouches. To seal the deal, you bind the scion and rootstock with a rubber band, tape, staples, string or wax.
Ferris Jabr at Scientific American goes on to explain what happens inside the branch as grafting takes hold. But you don't have to do it yourself. He also has links to several nurseries that sell fruit salad trees for your backyard. Link -via 80beats
(Image credit: Fruit Salad Trees)