30 THE WALNUT — BLACK. 



in diameter. The limb is sawed off and smoothed as for ordinary cleft 

 grafting; instead, however, of making a single cleft through the center, 

 two are made, one across the stub at each side of the center, the clefts 

 then being in sapwood instead of through the heartwood and pith. The 

 cion is prepared as for ordinary cleft grafting, for which purpose it is 

 best to use terminal shoots. In cutting the cion great care must be 

 exercised to cut only into the pith of one side. The cion having been 

 inserted, the wound is bound well with cotton cloth and thoroughly 

 waxed. 



(11) THE BLACK WALNUT (Juglans Nigra, Linn.). 



The relative merits of the black walnut for stocks to graft onto have 

 been under consideration for many years, and this root has been exten- 

 sively tried in this State, with satisfactory results. The variety mostly 

 used is the Juglans Californica, or California black walnut. (Plate X, 

 Fig. 11.) In a few instances Juglans Americana, or Eastern black wal- 

 nut (Plate X, Pig. 9), has been tried, but preference was given to 

 the former, being indigenous to our State. The Japanese walnut 

 (Juglans Sieholdiana) has also been tried, and has proved quite satis- 

 factory, but is not as strong a grower as the Californica. For a time I 

 was loath to believe the stock would influence the graft and cause it to 

 produce nuts of a dark shell. Experiments, however, have proved the 

 contrary. Trees now in bearing for over twenty years show no varia- 

 tion in color of shell, but an improvement in kernel and quality of the 

 nuts. The stocks are thrifty and healthy, easy of propagation, and 

 easily budded and grafted. Some twenty years ago I commenced experi- 

 menting in grafting and budding the wild walnut, with very satisfac- 

 tory results. A plot of Juglans rupestris, growing along the mountains 

 in Los Angeles County, was worked over to different varieties very satis- 

 factorily, but the stock is quite scrubby and of such dwarf habit that it 

 can only be recommended for dwarf purposes. The grafts took well and 

 made splendid growth. In all tests made on trees in the wild state, 

 nuts were produced on buds and grafts the second and third years. In 

 some cases the nuts were quite small, due perhaps to the stunted con- 

 dition of the stocks, for all must have been very old. The buds and 

 grafts that made the strongest growth were on stocks which did not look 

 so aged. These are now producing fine nuts, equal to those from the 

 parent tree. 



The oldest walnut orchard budded on the Californica is at Winters, 

 Yolo County, and the trees are over twenty years old. This orchard has 

 produced fine crops yearly and the nuts show a marked improvement 

 over those produced by the parent trees. 



At Vacaville two rows of large black walnut trees (/. Californica) 

 were worked over to different varieties of the " English " or " Persian " 

 walnut very successfully, by ' the prong bud method, described else- 

 where, and the ordinary cleft sap graft. The trees were planted some 

 thirty years ago for shade along the roadside. In the winter of 1892 

 the limbs were cut back to the crotch or main stem. In the spring they 

 put forth numerous shoots, which were thinned out to a dozen or so to 

 each tree, according to the spread of the branches. These new shoots 

 were budded in the summer. Those that did not " taike " were grafted 

 in the winter. Thus a fine stand of buds and grafts was obtained 



