Grafting an orange tree is usually performed to join the fruit-bearing qualities of one type of orange to the disease-resistant and hardy root stock of another. To accomplish this, a live cutting is implanted into the root stock tree. The growth that comes from the cutting will bear fruit that is identical to the tree it was taken from. A type of grafting called T-budding is the preferred method for grafting orange trees.
Gather a branch with buds from the desired orange tree. The branch should be mature growth from the previous season and up to 1/2 inch in diameter. Gather the branch in the summer when the bark slips easily from the wood.
Remove the bud branch from the tree with the pruning shears and clip off any leaves. Wrap the branch in a damp cloth or sphagnum moss to keep it moist.
Remove a bud to be grafted from the branch by cutting under the bud, starting about 1/2 inch below the base of the bud and ending 1/2 inch above it. Trim the top edge of the bud's bark square to form a little shield.
Remove the inner wood under the bark of the bud by gently squeezing the cutting, until the wood comes loose. Do not let the newly removed bud dry out.
Make a T-shaped cut through the bark of the trunk on a young tree selected as the understock. Be careful not to cut too deeply. Lift the corners of the cut with the tip of the knife to loosen the bark from the trunk.
Slide the pointed part of the bud's bark into the T cut so that the bark is under the root stock tree's bark. Insert the bud until the top of the shield meets the cross cut in the T.
Wrap the trunk with rubber band strips to hold the bud in place. Do not cover the bud.
Check the bud after two weeks to see if the graft has taken. The bud should remain dormant until next spring.
As the bud starts to grow, cut off the stock above it. Remove any shoots sent out by the root stock to encourage the new bud to grow.