The second period for successful plate budding of the walnut centers around August first, varying somewhat with the weather conditions. Buds of the current season's growth are used. The time must be late enough for these buds to be well matured, and early enough so that the stock is still growing and the bark slipping. If the buds are immature, or the bark tight, the operation will be a failure.
The buds remain dormant during the following winter, and are forced into growth by cutting off the stock above the bud early in the spring. The tying material, if durable, should be removed about 30 days after budding.
If conditions are right and the work is properly done, a high percentage of "takes" may be expected. In summer I preferably place the bud on the shady side of the stock, or shade it with a little skirt of white paper tied just above the bud.
Chestnuts can be budded by the same method, but the spring budding should be done earlier, while the stocks are in bud, and the summer budding should be done two or three weeks later than with the walnut.
I have not tried the plate bud on hickory or pecan, but it is the only budding method I use on walnut and chestnut, and I have tried them all.
When it comes to grafting, the simple splice graft, as illustrated, is very successful, but it should only be used when scion and stock are of the same size. It works splendidly on chestnut, filbert and hickory, and can also be used on walnut; however, I prefer the modified cleft graft for the latter, because of the bleeding problem.
In making the splice graft, the diagonal cut should be about four times as long as the diameter of the scion, to prevent slippage in tying.
For the modified cleft graft I cut the stock off at the selected point at an angle of from 45 to 60 degrees. This greatly facilitates the healing of the entire wound.
The cleft is made not by splitting, but by making a cut with a sharp knife, beginning at the apex of the stock and cutting diagonally downward and inward toward the center of the stock.
Before making the cut, the scion should be selected, and the wedge cut, with one face slightly longer than the other. This enables one to properly judge the depth and angle of the cleft, thus securing a fit on all four cambial lines. The longer face goes toward the main body of the stock, and is left slightly above the top of the stock. The apex of the stock is squared off slightly before the cleft is cut, and the knife is set very slightly on the wood at the starting point, rather than between the bark and the wood. Care at this point guarantees very rapid healing, with no dead tissues or "heel" on the stock, sometimes called "dieback."