Cambium:a single layer of dividing cells between
the bark and the wood. The cambium layers of the stock and scion must be in contact for a
union to form.
Clone: a group of individual plants asexually
propagated from a single plant and, therefore, genetically identical.
Grafting wax: used to protect a graft. Typically
made using 5 pounds of resin, 1 pound of beeswax, 1/2 pound of powdered charcoal and 1/2
cup of raw linseed oil. This mixture requires a heat source to keep it liquid while it is
used. Suitable commercial substitutes are available.
Scion: a twig or shoot that serves as the aerial
portion of the graft.
Stock: the portion of the plant that serves as
the rooted portion of the graft.
Grafting Principles: The cambium layers of both
the stock and the scion must come in contact. After the graft is made, protect it from
drying, disease, and independent movement of the stock and scion. Allow for unrestricted
growth -- grafting materials must be stretchable. Scion wood must always be right side up
for the graft to take.
A bridge graft or inarching is used to bridge over girdled areas
of a tree that generally are caused by gnawing rodents. Repair the damage as soon as the
bark slips (peels easily) in the spring. Obtain scion wood from the tree, bevel the ends
and slip these into T cuts made above and below the girdled area, allowing a substantial
arch. Nail in place and protect with grafting wax. Nearby seedlings or root suckers may be
used by grafting them to the tree above the girdle.
A bud graft is used to asexually propagate stone fruit (peaches,
plums, etc.). It also may be used to propagate many other plants. This method has the
advantage of using very little scion material (one bud), and survival is usually higher
than with other grafting methods. A disadvantage is that it must be done during a brief
period in the spring when the bark slips.
To make this graft, remove a chip of wood containing a leaf with
its axillary bud. Make a T cut in the stock and clip off the leaf blade, leaving just the
petiole (leaf stalk) stub to serve as a convenient handle for manipulating the chip. Next,
remove the wood adhering to the bark of the chip. Do not touch the cut areas with fingers
-- use a knife point. Insert the bark with its bud and petiole into the T cut. Wrap with
rubber budding tape or a suitable substitute. It is not necessary to use grafting wax, nor
is it necessary to remove the wood chip. However, removing it reduces bulk and there is a
greater area of contact between the two cambium layers.
A cleft graft is used for top-working larger trees to change to
another variety or introduce a new pollen source. To top-work a tree to another variety,
cut back half of the main limbs to where they have a diameter of 2 to 3 inches. A cleft
graft is performed in these stubs at this time. The following year the remaining limbs are
cut back and cleft grafted.
To make the graft, split the stub with a special grafting tool or
with a hammer and hatchet. Hold the split open with a screwdriver and position beveled
scions in the split so their cambium layers align with the stock cambium. Withdraw the
screwdriver and seal with grafting wax. This graft may be made during the late winter or
early spring while the wood is dormant.
A whip graft uses scions and stocks of approximately the same
diameter. This graft is used primarily on year-old seedlings that are being converted to
named varieties by removing their tops and replacing them with scion wood. This graft can
be done during the winter in the root cellar where the fall dug stock is stored. This is
an advantage because yard chores are not as numerous in the winter. To make this graft,
remove the top from the stock with a diagonal cut and split the cut surface vertically.
Select a piece of scion with two or three buds and make a matching diagonal cut. Slip them
together , wrap with rubber grafting tape, and coat with grafting wax.
