'Budding' refers to the particular form of grafting best suited for the propagation of citrus trees. In a bud graft, a bud, along with some bark (budwood), is removed from the variety of tree (scion) the grower is trying to propagate. The bud is then inserted beneath the bark of a host tree (rootstock). As the 'T' budding procedure is the one generally recommended for the inexperienced grower, it is the one we'll describe below.
Select the variety of tree you wish to cultivate. Look for a tree that is vigorous and healthy. Remember that some states prohibit the importation of budwood due to disease concerns so check with local authorities if you plan to use imported budwood or even budwood from quarantined areas of your own state.
Budwood is usually collected during the growth period between April and November when the bark can be separated easily from the wood. Carefully collect rounded budded twigs that have begun to harden. Do not use very young buds from the current growth flush. Trim the budwood to 8 or 12 inch lengths. Try to use the collected budwood as soon as possible. If you must store the wood for a period, place it in a sealed polyethylene bag in the vegetable crisper of your refrigerator. Check periodically for moisture build-up or mould. Use the stored buds within 3 months.
Select the young citrus tree that you wish to use as rootstock. Look for a variety of tree best suited for vigorous growth in your area. With a sharp knife, make a one-inch vertical cut through the bark of a healthy rootstock stem about six inches above the ground. At the bottom of the vertical cut, make a horizontal cut, the two cuts forming an upside down 'T'.
Using your knife, remove a bud along with a one-inch sliver of wood and bark from a budded twig. Carefully insert the bud under the flaps of the 'T' cut of the rootstock with the wood of the bud sliver completely enclosed by the 'T' flap. Wrap the graft with budding tape making two or three rounds below the bud and two or three rounds above. Wraps should be removed not later than 30 days after the graft. A green, healthy looking bud will indicate that the graft has succeeded.
In order to stimulate the growth of the union, the bud must be forced into growth. To force growth, cut 2/3 of the way through the rootstock about 1.5 inches above the bud and on the same side as the bud. Then push the rootstock over to lay on the ground. After the bud has grown 3 to 4 inches, the top of the rootstock can then be cut off about one inch above the top of the bud. To prevent competition from rootstock buds, they should be removed as soon as they develop.
The above images and image captions have been reproduced from Fact Sheet HS-86, a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: August 1991. Revised: June 1994.