Grafting a lime tree is usually done to combine the good fruit-bearing properties of one type of lime with a disease-resistant, hardy rootstock. This is done by implanting a living bud from one tree into the trunk of another tree. The resulting growth from that bud then bears fruit that is genetically identical to the tree it came from. A method of grafting known as T-budding is the preferred technique for grafting lime trees.
Creating the Graft
Collect a branch with fresh buds from the desired lime tree. The branch should be taken from the previous season's mature growth and can be up to 1/2 inch in diameter. Gather the branch in the summer when the bark slips easily from the wood.
After removing the bud branch from the tree, cut off any leaves and wrap the branch in a damp cloth or sphagnum moss to keep it from drying out.
Remove a bud to be grafted 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 shape.
Remove the inner wood under the bark of the bud by gently squeezing the cutting until the wood comes loose. This forms a bud chip. Do not let the bud chip 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.
Slip the pointed part of the bud chip into the T cut so that the chip is under the rootstock tree's bark and the bud is facing out through the cut in the trunk. Insert the bud chip until the top of the shield meets the cross cut in the T.
Wrap the trunk with rubber band strips to hold the bud chip 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 the following spring.
As the bud starts to grow, cut off the stock above it. Remove any new shoots sent out by the rootstock.