Grafting is not hard to do. The easiest to make and best known and most practical form of it, for general use, is the cleft graft. No matter how many forms grafting may take – the Romans are said to have had 50 – the fundamental principle underlying all is that of uniting the cambium of the cion with that of the stock so that food supplies can be conducted from the one to the other.
For it is through the cambium layer that a tree is fed, and if the cambium of the cion can he united with that of the stock, food will flow up into the Lion and it will grow just as if it had never been cut away from its original source of supply.
The cambium is the green layer between bark and wood. As viewed in the top of a stock about to be grafted early in the season, it is not sharply defined but is rather indefinite; at that time the grafter has to do a good deal of estimating as to just where the cambium is.
Nevertheless, that is the best time for the cleft graft because under those conditions the bark sticks tight to the wood – an essential for the cleft graft. Later in the season – generally about midspring – the cambium presents a definite line, and that indicates that the bark is likely to slip and, if it does, the cleft grafting season is over.
Now for the tools to do the job. Common carpentry tools can be used but for the man who wants the pleasure and convenience of the right thing there are four items lie will enjoy: a good grafting mallet, a grafting chisel with a high quality white handle (so it is easy to find), a horticultural knife, and a wedge for stocks that are too small for the wedge on the grafting chisel.
The mallet can be made from a hard wood like dogwood. It should be shaped liked a short thick policeman’s club and should have a knob like that on a bowling pin with a rawhide lace through the knob to permit hanging from the wrist. The grafting chisel designed by the New Jersey Experiment Station; it is rather expensive because it was to be made to order. The wedge for small stocks can be made by a blacksmith out of an old flat file; it is a splendid tool. A substitute for it can be a screwdriver, and for using on the big stocks, a cold chisel.