Publication 457 - Revised by John W. Jett (1997)
Cleft-grafting, the most popular method of grafting apples and pears except in the
nursery, is perhaps the oldest method of grafting because of the simple procedure.
Cleft-grafting may be performed on main stems or limbs, providing they are one to two
inches in diameter.
Cleft-grafting is relatively simple to do but there are certain steps that should be
carefully followed to obtain the desired results.
- Select scions from well-developed terminal growth of the previous season, preferably
those that made a growth of 12 inches or more. Gather the scions when they are dormant,
and store them where they will remain dormant and not dry out (like in a plastic bag in
the refrigerator) until time of grafting. (Actual grafting is best done in the spring when
the bark of the understock begins to slip.)
- Choose a smooth section of understock to receive the scion. This area should have
straight grain for at least six inches below the cutting point. This area should also be
free of spurs, knots, and cankers. Remove the undesired section with a fine-tooth saw just
above this point.
- Using a grafting blade (clefting tool) or a clean sharp blade, make a clean cut or cleft
two to four inches deep. Cut the bark ahead of the split if it does not part evenly. If
the graft is to be made on a branch growing on a horizontal plane to the ground, the cleft
should also be made horizontally to the ground rather than vertically. Otherwise the
bottom scion may grow upward into the upper scion.
- Remove the blade and insert wedge into the center of the cleft to hold it open for the
insertion of the scion (Figure 1).
- Cut off a piece of scion wood containing three or four strong buds and, starting at the
base of the lowest bug (Figure 2A), make two smooth, straight cuts to form a blunt wedge
one to two inches long. The side containing the lowest bud should be slightly thicker than
the other edge (Figure 2B). Note that the taper is not too great. (Generally two scions
are used per graft.)
- Insert these scions into the cleft, one at each side as shown in Figure 3. The lowest
bud on the outside of the scion should be placed just above the cleft, making contact
between cambium layers of the stock and scion (Figure 4). It should be noted that the
cambium layer is a very thin, colorless layer between the bark and the wood.
- Remove the wedge carefully (by moving it back and forth sideways) in order not to
disturb the scions and permit the cleft to close solidly on them.
- Cover all cut surfaces with a nontoxic asphalt emulsion or with grafting wax --
preferably brush wax (Figure 5). Make certain that all spaces around the scions are filled
with coating, eliminating all air pockets and preventing water from entering the graft.
- Check the scions periodically to determine the success of the graft. If both scions have
"taken," one should be dwarfed after the first year to allow for better growth
of the other (Figure 6A). The dwarfed scion may be completely removed as the cleft begins
to seal completely. If one of the scions dies, that portion of the understock should be
removed after the second year (Figure 6B). The cut should be coated with a tree wound