Engrafting, or GRAFTING a term in gardening, which signifies the taking a shoot from one tree, and inserting it into another, so that they may closely unite, and form one trunk.
Grafting has been practised from the most remote antiquity; but its origin and invention are differently related by Naturalists. The great aim of this useful art is, to propagate any curious sorts of fruit-trees, to insure the growth of similar kinds, which cannot be effected by any other method : for, as all the good species of fruit have been accidentally obtained from seeds, many of these, when sown, will degenerate, and produce bad fruit. But, when shoots are taken from such trees as bear good fruit, they will never change their kind, whatever be their stock, or the tree on which they are grafted.
Mr. Bradley observes, that, the stock grafted' on, is only to be considered as a fund of vegetable matter, which is to be filtered through the cyon, digested, and brought to maturity, as the time of growth in the vessels of the cyon directs. A cyon, therefore, of one kind, grafted on a tree of another, may be rather said to take root in the tree it is grafted, than to unite with it: for it is obvious that the cyon preserves its natural purity, though it be fed and nourished by a mere crab.
The grafts or cyons with which this operation is effected, should be of the last summer's growth, from the outside branches; firm and well ripened; and selected from healthy trees. The graft is always the middle part of each shoot, cut to 5 or 6 inches in length, or so as to have 4 or 5 good eyes, or buds, but should be preserved at full length, till grafting time.
The proper tools and other materials used in grafting, are : 1. A strong knife for cutting off the heads of the stocks, previous to the insertion of the graft; also a small hand-saw, for occasional use, in cutting off the heads of large stocks ; 2. A common grafting-knife, or strong sharp penknife, for cutting and shaping the grafts ready for insertion; also to slope and form the stocks for the reception of the cyons; 3. A flat grafting chisel, and small mallet for clefting large stocks, in cleft-grafting; 4. A quantity of new bass-strings for bandages, for securing the grafts, and promoting' their speedy union with the stock ; and 5. A quantity of clay, for applying closely round the grafts after their insertion and binding, to defend the parts from the influence of the sun, winds, and wet weather, or from being affected by cold.
For this purpose, a kind of stiff loamy mortar may be prepared of strong fat loam; or any other tough clay may be substituted ; to which may be added a fourth part of fresh horse-dung, free from litter, and a small portion of cut hay, with a little water, well mixed : the whole should be properly beaten with a stick,and thus incorporated.
This operation should be repeated, according to the nature of the clay, and performed several times during the first day ; the composition being still moistened with water for six or seven days successively, at the end of which time it will be fit for use.
There are various other modes of engrafting, which are termed whip-grafting, or tongue-grafting, cleft-grafting, crown-grafting, root-grafting, cheek-grafting, side-grafting ; and, lastly, grafting by approach, or Inarching (to which we refer). Beside this last-mentioned, the following are most commonly and successfully practised:
1. Whip-grafting, or tongue-grofting, is generally performed in nurseries, upon small stocks, from a quarter of an inch to half, or a whole inch in diameter. The stock, and cyons or grafts, should always be of the same size, or approach as nearly to the same size as possible. They are both to be sloped off a full inch, or more, and then tied closely together. This method may be much improved, by performing what gardeners call tongueing, or tipping ; that is, by making an incision in the bare part of the stock, downwards, and a similar slit in the cyon, upwards; after which they are to be carefully joined together, so that the rinds of both may meet in every part, when a ligament or bandage of bass is to be tied round the cyon, to prevent it from being displaced; and the whole is to be covered over, or coated, with the clay above de-scribed.
2. Cleft-grafting, or slit-graft-ing, as gardeners differently term it, is performed upon stocks from, one to two inches in diameter. The head of the stock being carefully cut off, in a sloping direction, a perpendicular cleft, or slit, is to be made about two inches deep, with a knife or chisel, towards the back of the slope, into which a wedge is to be driven, in order to keep it open for the admission of the cyon: the latter must now be cut in a perpendicular direction, and in the form of a wedge, so as to fit the incision in the stock. As soon as it is prepared, it should be placed in the cleft, in such a manner that the inner bark of both the stock and cyon may meet exactly together. It is then to be tied with a ligature of bass, and clayed over, as is practised in whip-grafting, three or four eyes being left on the cyon uncovered. The proper season for this mode of grafting is the same as for the preceding, viz. the months of Febuary and March: towards the latter end of May, or the be-ginnng of June, the junction of the graft and stock will be completed, and the latter begin to shoot 5 when the clay may be taken off, and, in the course of a fortnight or three weeks, the bandages may be removed.