A tree that bears two kinds of fruit is a novelty that will amaze you, summer after summer. Double fruit trees are not found in nature; they are grown by grafting a branch from one tree onto the base of another tree. You can buy mixed fruit trees at specialty nurseries and orchards, or you can graft your own tree with two kinds of fruit.
There are two keys to successful grafting: (1) both the species of the base tree and the species of the branch must be able to grow in your climate, and (2) the species must be closely related.
Drupes such as cherries, plums, apricots, and peaches may be combined on a single tree. Likewise, you can create a tree that produces different varieties of apples. You can even splice together different citrus fruit trees, such as orange, mandarin, lemon, or lime.
First, select the base tree. The base tree should have a strong root system, but still be young and pliable enough to accept a transplanted branch. A tree that is 5-7 feet tall and 2-3 inches in diameter is perfect.Cut a wedge out of the trunk of the tree. The notch should be 4-6 inches long and cut halfway through the trunk, going downward. Make the notch close the base of the tree if the to-be-grafted branch is heavy, otherwise you can cut the notch higher up.
Next, choose the branch to graft onto the base tree. A branch from a young tree or sapling is best. Make sure the branch comes from a similar tree species, or else the branch will rot and fall off. Cut the end of the branch so that it fits into the notch you created earlier. Remove excess bark from the end so that when you apply the graft, bare wood touches bare wood as much as possible. Spray the inside of the notch and the end of the branch with water, then insert the branch into the base tree. Wrap the seam with rope or grafting sealer so that the cuts are completely covered. Stake the tree for stability.
Keep the rope wrapped around the tree until the trunk has noticeably increased in diameter. Then you can loosen...