My best success with the propagation of nut trees has been with the following methods. For budding, I use the plate bud exclusively. For grafting on stocks up to one inch I use either the splice graft or the modified cleft graft. For larger stocks I use either the simple bark graft or the slot bark graft. Each will be discussed in order.
In making the plate bud, it is cut from the scion or bud stick the same as for the familiar T bud. Usually a bit of wood is cut away with the bud, which should not be removed. A bud, or a bit of bark, should similarly be cut from the stock at the desired point, and discarded. The area of exposed cambium on the stock should correspond as closely as possible with the cambium area exposed on the bud. The bud is then laid on the exposed cambium of the stock, and bound in place, preferably with rubber budding strips. The point of the bud should be left exposed.
[Illustration: SIMPLE BARK GRAFT Useful with thin-barked species.]
Choice of time when conditions are right is quite as necessary for success as the proper procedure. There are two separate periods when the plate bud may be used on walnut with the greatest success. The first period, in Virginia, is the latter half of May, when the black walnut stock is in almost full leaf. If done earlier the bud is likely to be drowned by the excessive bleeding of this species. Dormant buds cut the previous winter are used.
The follow-up care is vitally important. The stock should be cut off above the bud within five to seven days after budding. If successful, the bud will start into growth within another week or ten days, and may be a foot long within 30 days.
[Illustration: 1. Slot bark graft; useful in top-working.
2. Splice graft; unexcelled when scion and stock are of equal diameter.
3. Modified cleft graft; for all general purposes.
4. Plate bud; for small and medium stocks.]
The tying material should be cut and removed within a few days after the bud starts, to prevent strangulation of the tender shoot. Be sure to keep native growth of the stock trimmed off until midsummer to force growth of the bud.