Australian and New Zealand Gardening: Budding & Grafting Plants, 1 by Stake

Stake wrote:
The first thing I need to tell you about is the Cambium layer. The Cambium is absolutely essential knowledge for grafting success.
If you get a piece of strongly growing plant you will be able to peel the Inner Bark back and see a shiny gooey film, this is the Cambium. The Cambium is the part of a plant that can become any part of the plant that is needed. In a healthy, uninjured plant the Cambium becomes on the inside living wood on the outside living bark. If the plant is injured the Cambium at the injury site becomes Callus tissue (This is what occurs at the base of a cutting) to heal the wound. When you have two compatible Cambiums as in a graft then a union is formed. You must have the Cambiums lined up or your graft won't (can't) take (no union). If you are doing a T bud the piece where the bark is lifted exposes the Cambium for the whole section, with the other methods only a thin line of Cambium is exposed and the same applies to the scion. If you cut a piece of growing plant on an angle you can see, on the outside Bark which is sometimes two layers "Dead Bark" & "Living Bark" then a thin line of Cambium followed by "Living Wood" then "Heart Wood" and a varying small ring of "Pith". Only the Cambium really matters and the Cambiums of both stock and scion must be matched the closer to perfectly the better the chance of success. The degree of matching varies with different plants for example, Cherries will usually form a successful union if only matched on one side whereas a Peach needs almost perfect matching.
I suggest that before you start grafting you familiarise yourselves with the Cambium, first peel the bark on some spare material with your finger nail then make a cut and lift the bark so you can see the Cambium then make the different types of cuts and observe where the Cambium layer is. You cannot match the Cambium if you don't know what it is or where it is. Although it might seem self evident I'll say it any case. Practice with non valuable material, this might just be from a big specimen of the plant you want to graft or from any vigorously growing plant available.
The easiest graft to carry out is the "T" bud because the Cambium is exposed for the whole exposed area and the same with the "Bud Schield" scion if the sliver of wood is removed from the Bud Shield, if the wood is to be removed it must be gripped at the top end and pulled upwards until free of the Bud Schield, except with roses it doesn't matter which end. A lot of "T" budding is done without removing the wood but it pays to keep the cut shallow so only a thin piece of wood remains in the bud shield. "T" budding has its limitations for good success the bark should not be too thick (less than 2mm) and the diameter of the stock not too great (less than 25mm). In the photo there are two side grafts first is slightly left of centre in the foreground and just below the leaf to the right and behind it. The side graft is best where the bark and the limb to be grafted are thick like the Frangipani.
Brian