How to Graft an Orange Tree to a Lemon Tree

Lemon trees can be modified to produce oranges, or even to produce both oranges and lemons on a single tree. This is done through a process called grafting. Grafting one or more additional kinds of fruit to a single tree makes maximum use of limited space. More often, though, grafts are used to enhance production of just one kind of fruit by grafting it to the rootstock of a compatible tree that is better established or is more disease-resistant. The technique for grafting an orange tree to a lemon rootstock depends on whether you want to grow one or both varieties of citrus on a single tree.

Things You'll Need

• Pruning saw
• Grafting knife
• Grafting tool
• Mallet
• Chisel
• Paraffin tape or raffia
• Grafting wax

Instructions

The Cleft Graph (To Grow Oranges but not Lemons)

1. Wait until the growing season is underway. Saw straight through the trunk of a healthy lemon sapling at a height of around 3 or 4 feet. The trunk should be no more than 2 inches in diameter. The cut trunk will serve as the rootstock or base of your orange tree. Make the cut smooth and perpendicular to the ground.

2. Use a standard grafting tool, available through nurseries and nursery supply companies, and a small mallet, to make a downward slit about 2 inches deep through the top of the rootstock. This slit should extend all the way across the severed trunk of the tree.

3. Cut two healthy budding branches about 1/4 inch in diameter from an orange tree. Use them to fashion two scions for grafting to the lemon rootstock by making a sloping cut about 1/4 inch above the uppermost bud on the branch with your pruning shears or knife. Put a chalk mark near this cut so that you will later remember which end of your scion is "up."

4. Count down from the top bud two more buds so your scion will have a total of three buds. Cut the scion about 2 inches below the lowest bud. Repeat the process with the second branch so you have two scions each about 6 inches long to graft to the prepared lemon rootstock.

5. Use your grafting knife to shape the lower end of each scion into a two-sided wedge, leaving them slightly blunt at the end. Do not remove too much material. To graft the plants successfully with the rootstock, you must expose the layer of cells just under the bark of both the host rootstock and the scion and make sure they come into contact with each other. If you cut too deeply, you will remove this layer of cells, and the graft will not fuse.

6. Use a chisel or small wedge to gently separate the cut you made on the trunk with your grafting tool just wide enough to insert the pointed tip of the scion. Insert one scion on each side of the trunk so that the bark remaining on the pointed sides of the scions is roughly lined up with the bark of the rootstock and the scions are pointed upward. Even if only one of the two scions bonds with the trunk of the tree, your graft will be a success. If both bond, so much the better.

7. Wrap the graft with paraffin tape or tie the graft with raffia and then cover with warm grafting wax, all available at nursery supply stores, to protect the tree while the graft forms. Your tree will now produce oranges instead of lemons.

The T Graft (To Grow Both Oranges and Lemons)

1. Produce both oranges and lemons on your lemon tree by inserting orange scions onto a lemon branch using a T graph.

2. Use a grafting knife to make a straight cut about 2 inches long through the bark only on the top of a healthy 1- to 2-inch branch on your lemon tree. Make the cut at least a foot away from the trunk of the tree and away from other lateral branches. At the end of the straight cut farthest from the trunk, make a shorter cut perpendicular to the first, so that the cuts form a T.

3. Prepare one or more orange scions as before, except instead of making a wedge cut at the end of the scion, shave away only a flat surface on one side. Your goal will be to make this shaved end, which should be cut on about a 30-degree angle, lie flat against the host branch just under the bark. In this way, the rest of the scion should angle away from the host branch just like any other lateral growth.

4. Use the tip of your grafting knife to carefully lift the bark of the host branch on both sides of the T cut. Lift the bark only enough to insert the scion, then secure the graft with paraffin tape or tie and apply grafting wax as before. Choose a nearby branch to add any other scions you wish to graft to the tree in the same manner.

Tips & Warnings

• Test whether the plant is ready to accept grafting by attempting to lift a small section of bark from a similar sized branch. If the bark is difficult to separate, the tree may not be in a sufficiently strong growth mode to allow grafting. Grafting cannot be accomplished during dormant periods.

References

• Why is my Orange Tree Turning into a Lemon Tree?
• Graft of Crown