Mostcan be grafted on to other cacti. I have never heard of grafting practised on other kinds of succulent, but it is presumably feasible in some instances.
There are occasions when grafting helps a weakly or slow-growingto grow more strongly, or quickly, or allows the cultivation of species which are impossible to grow on their own . Sometimes a hanging cactus is grafted to the top of a columnar form to produce a result like a weeping standard rose. Apart from these more or less necessary cases, I think grafted plants are ugly and unnecessary, though sometimes grotesque combinations may elicit a reluctant fascination.
The basis of cactus grafting is to make flat cuts which correspond on stock and scion, and to press them together immediately. Horizontal, V or A -shaped cuts may be used. When the scion is a thin or flattened plant, such as Aporocactus orrespectively, a wedge graft is used; a narrow cleft should be cut in the stock, and the edges of the scion should be pared of the outer skin to provide sufficient cut surface.
Schliimbergera is sometimes grafted fanwise on to large Opuntia pads. Very thin round, such as of Pereskia, may be pushed into a hole in a large cactus. Various combinations will suggest themselves.
The two parts are generally pinned together, usually with an unbarbed cactus spine, which will not rust like a metal pin. Alternatively, twine is placed around the base of the pot and the graft, using paper or cotton-wool as padding if necessary. Weighted twine can also be used and avoids the need for making a knot.
Union should occur in a week or two. If the plants are pinned together, the spine should eventually be removed to avoid rotting; other fixing should be left for three weeks. In any case, great care should be taken to avoid jolting the union during the first three weeks. Nor should any water reach the point of union during this time, or rotting may occur. Otherwise conditions are the same as for normal plants.
Grafting should be done in summer when the day temperature is between 18 – 21 ° C. (65 — 70° F.), and when the atmosphere is dry. Full ventilation should be given to promote air circulation.