Many varieties of apple tree are actually hybrid varieties grown for their ability to resist pests and diseases such as apple scab. Because of this, if you try to grow an apple tree from seed, you may not get an an exact duplicate of the parent tree. Many hybrid apple trees are created by grafting a desirable hybrid apple tree branch onto the root stock of a less desirable apple tree such as a crabapple.
Collect apple tree cuttings for grafting (the scion) in fall when the tree goes dormant. The ideal scion is from new growth collected from an apple tree less than 5 years old. For older trees, collect scions from branches high in the tree's canopy.
Position your pruning shears at a point at least 6 inches from the end of the branch. The branch should be the size of a pencil, and there should be at least three points where leaves emerge from the wood (leaf nodes) on the branch. Cut through the tree limb and place the cutting in a plastic 1-gallon freezer bag along with a damp paper towel.
Store your cuttings through the winter in a refrigerator set to a constant 40-degrees-Fahrenheit temperature. Place the scions in a 1-gallon freezer bag along with damp peat moss to keep them from drying out.
Prepare to graft your apple scions onto crab apple roots (root stock) in spring when the tree begins to produce buds. Grafting should be done before the buds bloom. Select a crabapple branch for grafting to your cutting that is the same size as the cutting. Cut the end of the branch off at a 45-degree angle, using a pruning knife.
Cut the end of your scion in a 45-degree angle that mirrors the one that you just made in the root stock branch. Sandwich the scion to the root stock branch so that the cuts align and the bark of the scion and root stock are touching.
Wrap the graft in polyethylene grafting tape.
Remove the grafting tape once the graft heals together to avoid cutting off the tree's circulation to the new branch. Once the scion is grafted onto the root stock, train the new branch as a dominant leader and prune away the rest of the crabapple branches.