Grafting or propagating orange trees allows established root systems a fresh start and extends their fruit bearing years. Citrus plants are modern hybrids and therefore cannot simply be grown from a seed as the fruit produced on those trees is inedible. For a gardener with a small yard, citrus trees allow for an even more individualized type of grafting where multiple citrus fruits can be sustained on the same tree. These trees are called "cocktail trees."
Select the budsticks that will be used. Optimal bud sticks are roughly 1 year old and 1/4 inch or less in diameter. If grafting cannot be performed immediately, the budsticks can be wrapped in wet paper towels and stored in the refrigerator for up to 3 weeks.
Determine the location for grafting. The best branches to use are those that are 1/2 to 3/4 inch in diameter. Avoid placing the new bud stick in an area that will receive south or west sun exposure as it can become sunburned. Be sure to verify that the tree's bark is slipping before beginning the grafting process.
Sharpen the grafting knife. Grafting knives are a one-sided bladed knife that must be razor sharp for proper grafting. To test the blade, carefully shave some arm hair. If the hair comes off easily, the blade is sharp enough. If not, consider having the blade professionally sharpened before grafting.
Use the sharpened grafting knife to make a vertical cut approximately 1/2 inch in length and deep enough to cut into the wood. Make a horizontal cut underneath the vertical cut also 1/2 inch long. When finished, it should appear as an inverted "T."
According to John Begeman, Professor at the University Of Arizona Department Of Horticulture, budsticks are created by "selecting a plump dormant bud located at the point directly above where a leaf petiole attaches on the stem. Make a horizontal cut across the bud stick about one-half to three-quarter inch above the bud. Cut the bud and a small piece of wood underneath it using a continuous motion. The cut should begin about one-half to three-quarter inch below the bud and should end at the horizontal cut made above the bud. Lift the chip of wood containing the bud using the leaf petiole (leaf removed) as a handle. This will avoid contaminating the cut side of the bud chip with soaps or oils from your fingers."
Carefully peel back the bark from the "T" cut, and slide the chip inside. Push the bud chip down from the top of the "T" toward the bottom until the bark firmly holds the new bud in place. Be sure to position the bud so that it will grow in the same direction as the branch.
Tightly wrap the graft with budding tape. The wrap should be stretched so tightly that it is almost to the point of tearing while wrapping the plant. Continue wrapping until the two are firmly attached to one another. Wrap the graft so that only the bud and leaf petiole are peeking out. This will ensure that the graft remains moist enough for proper healing to take place.
Remove the wrap after a few weeks. If the graft was successful, the bud will have turned into a new shoot.