BULLETIN 231] WALNUT CULTURE IN CALIFORNIA. 235 



or a modification of the same. Some operators simply split the stock 

 through the middle, insert the wedge in the cleft, trim the split edges 

 of the bark and cambium smoothly with a sharp knife, cut the scion 

 to a smooth bevel on either side, and insert the same carefully, taking 

 special pains to make a good fit and bring the cambium layers of the 

 stock and scions into intimate contact. After removing the wedge some 

 grafters fill the cavity across the heart of the stub with paper or some 

 other material before waxing. Another, and in our opinion somewhat 

 better method of cleft-grafting, especially on stubs more than two 

 inches in diameter, is that shown in Fig. 35. This differs from the 

 ordinary method in that instead of making one cleft across the middle 

 of the stub two or more are made at uniform distances apart out 

 near the edge, splitting off slabs about one half an inch in thickness. 

 A special tool is useful both for this or for ordinary cleft-grafting, as 

 shown in Fig. 35. In making the splits the splitting wedge is held 

 in a horizontal position over the place where the cleft is desired and 

 driven in to a depth of about one half inch. It is then tilted up in a 

 slanting position and driven down to a depth of one and a half to two 

 inches, first at one end of the cut and then at the other. The limb in 

 Fig. 35 was 3J inches in diameter. In this two clefts were made, 

 each J inch thick by 2J inches long and 2 inches deep. The rough 

 edges of the bark were smoothed with a sharp knife and the cleft held 

 open with the terminal portion of the tool, as shown in Fig. 36. The 

 proper scion for such grafting is shown in Fig. 34. This is prepared 

 by beveling off one end into a wedge shape, cutting entirely through 

 the pith on one side, and then down to the pith on the other. The back 

 side of the wedge, that which is placed toward the outside of the tree, 

 is made wider than the side which goes toward the interior of the tree. 

 There should be two buds on each scion, one near each end as shown 

 in the illustration. Two scions are carefully fitted into each cleft, 

 taking great pains to make a good fit and bring the cambium portions 

 of stock and scion into intimate contact. If the bark splits irregularly 

 it should be smoothed with a sharp knife. In all cleft grafting it is 

 well to slant the point of the scion a little toward the center of the 

 stock so that the upper end of the scion points out a little in order to 

 be certain that the cambium may cross at least at one point. In 

 grafting limbs up to 4 inches in diameter two clefts or four scions 

 are commonly put in by this method. In larger limbs more clefts and 

 scions may be used. It is desirable to put in as many scions as possible 

 without at the same time splitting off slabs of too little thickness, since 

 the more scions that grow the quicker will the cut surface heal over. 

 It is much better to get several scions started, even though it be neces- 

 sary to cut off all but one the following year rather than having only 



