H. LYNN TUTTLE, Clarkston, Wash.
It took man some thirty thousand years to learn to build a fire—conveniently. I thought it was going to take me that long to learn how to bud walnuts, but fortunately the period has been somewhat shortened.
When I first began to propagate, or try to propagate, walnuts, I naturally looked to the approved and accepted methods. For me, they did not work. Before I was through I think I tried them all. I patch-budded with variations and improvisations. I shield-budded and bark-grafted. I coated the wounds with grafting-wax, latex, cellophane, asphalt and paraffine. I trimmed off the bud shoulders to make a smoother tie and trimmed around the edges to make more contact. I wrapped with raffia, strings, rags and rubber strips and tacked with small nails. Whatever I did or however I did it results were all about the same—the sap soured. In fact over a period of years I tried every way I could think up or read about to bring the bud and the cambium layer together and make them stick. Results were surprisingly uniform—the sap soured.
But we must not dwell too long on the shots that missed. As with a refractory engine that will suddenly sputter, there came some elements of success. The point to learn was, why? Concentrating on the shield bud entirely we determined to find these whys. So we tried taking big slabs of bark along with the bud, peeling out the wood, breaking off the leaf stem entirely and waxing the scar and making an unnecessarily long cut for the bud. The bark stuck fairly well but the buds died. This was some encouragement and I knew that with enough time, reason and a little luck we would eventually hit the mark.
Now Dame Fortune had decreed that I be raised on a grain and stock ranch where the only trees we could see were in the distant mountains, or, if we rode in the canyons, cottonwoods and choke-cherries. My experience and training was with animals, and animals, especially horses, seem quite susceptible to accident. The first principle of treating almost any wound is to give it drainage, otherwise, both literally and figuratively, the "sap" soured. Thus it dawned on me that a tree-wound, even if only skin deep should have the same treatment as a flesh wound. And drainage, being desirable, should be ample.
It was quite late in the season but I went out and set a dozen Schafer walnut buds on eastern black stocks. These buds HAD DRAINAGE. The vertical cut of the T extended at least two inches below the bud. Success ensued, they grew. The following spring we budded as soon as the bark would slip and continued at intervals all summer. Results were good. Some of the steps we now use are probably not essential and perhaps not even the best, but there are two points that cannot be over-emphasized, namely, drainage and contact. The complete method is as follows: 1. Trim bud sticks to leave an inch of petiole on the bud. 2. Make the T cut with a long vertical slash that will extend at least an inch below the bottom of the bud. 3. Cut the bud long and deep and peel it from the wood by pinching the sides. Be carefull not to injure the bark just below the bud. 4. Insert the bud either flush with or below the cross-cut. 5. Wrap with large sized rubber budding strips just firmly enough to make good contact. Too tight wrappings curtail circulation. Do not cover the cut below the bud. The wound must have drainage. 6. Be sure that the center of the bud-cut is firm against the cambium layer. If it humps of bows and won't stay down insert a tooth-pick or bit of leaf stem or something along the center line to hold it down. We usually do this during the wrapping process.
We use no wax. We throw a wrap over the bud, shoulders even though it may press the petiole forward against the bud. If the center of the bud pulls out it will not grow although an adventitious bud may eventually start. Budding seems about equally successful any time that the bark slips freely. On walnuts this is all summer if not too dry.
Early-placed buds may make several feet growth before fall if sufficient moisture is available. On walnuts there are always dormant buds. We have used storage wood but now just cut it fresh. We have not tried draining patch-bud or grafts. Although we have not tried it we think cherries and other trees inclined to drown the buds might be better handled in this manner. Climate is a factor in the type of propagation advisable. One very fine grower using buds in California could propagate only by grafts when he moved to Western Oregon.
The kernel of my walnut budding experience may well be summarized in one word—drainage.
Questions asked Mr. Stoke after his demonstration of grafting and budding.
[See his paper in 1946 Report, pp. 99-103.—Ed.]
Member: "How do you keep your scions?"
Stoke: "I prefer 'orange' cold storage for scionwood. This is just above freezing. Walnuts should be in full leaf before spring budding."
McDaniel: "What percentage of chestnuts did well with the 'plate' method of budding?"
Stoke: "I don't use it with chestnuts for spring budding, but sometimes for summer budding. It will work well on any variety of Persian walnut, heartnut and black walnut. Place buds on the north and northeast side of tree to prevent sun injury."
Question: "Do you find any difference in using buds from an eight or ten year old tree as against a younger tree?"
Stoke: "No, not so long as it is healthy. For spring budding I don't care to have any trees too vigorous. Cut tops off young trees three to five days after budding, and force the buds into growth. If you delay too long the bud will die. I wouldn't try to bud trees unless bark is slipping."
Member: "I have used parapin wax and covered it with old bread paper."
Stoke: "That may work because the wax was shaded. Southern sun may melt parapin and paraffin waxes."
Mr. Corsan: "Dentists, surgeons and wood carvers make the best grafters."
Question: "Can the scions be cut with a small plane?"
Stoke: "Anything you have to cut with a plane is too big. I never use a plane."
Question: "What do you use a splice graft for?"
Stoke: "Anything except walnut. In walnut I use a modified cleft graft, and I take care of the sap flow by placing the graft down about 1" or 1¼" below the cut (where the tree is cut off). Wax the scion but do not wax the cut. Let it bleed."
Question: "What is the value of cut leaf black walnut?"
Stoke: "Purely ornamental. Weschcke reports that it is very hardy with him."
Rick: "What about the Lamb walnut?"
Stoke: "We don't know whether the wood of grafted trees is curly or not. I sent Mr. Reed a limb from Lamb and he gave it to the forest laboratory and they found no evidence of curly grain."
Rick: "Shouldn't it be propagated until we are sure?"
Stoke: "We had Mr. Lamb himself talk before us at Roanoke and he told us about the parent tree. He doesn't know what makes one tree curly and another not."
Korn: "Is that uncommon?"
Stoke: "Not so very. Trees are most curly at the base and in the outer wood."
Question: "Do you always leave that stub on black walnut?"
Stoke: "Yes, but it should be removed later in the first summer."
Question: "Where do you use your splice graft."
Stoke: "On anything other than walnut, if scion and stock are the same size. Where stock is larger than scion I use the modified cleft graft up to sizes approaching one inch in the stock. For topworking larger stocks I use one of the forms of bark graft. For the large hickory stock Dr. Morris' bark slot graft is preferred. For large, thin-barked stocks the simple bark graft may be used. My original grafts of the Carr and Hobson Chinese chestnuts, made with scions received from Messrs. Carr and Hobson in the winter of 1932, are still perfect unions.
"I believe that grafted chestnuts growing in frost pockets are most likely to develop faulty unions; possibly frost injury to immature cells at the junction point may occur. Dr. Crane mentions a similar failure of unions between Persian and black walnuts on the Pacific Coast."
Dr. Crane: "What cut did you use in grafting those chestnuts?"
Stoke: "Modified cleft. In using Dr. Morris' bark slot graft I find it best to leave just a little of the cut face of the scion wedge above the top of the stock. This, with top of the stock cut sloping away from the scion, as illustrated, promotes quick healing with no 'die-back.'"
Dr. Smith: "Is that top slanting?"
Stoke: "Yes, I cut it slanting."
Dr. MacDaniels: "That is a good graft for walnuts, too."
Note: Mr. Stoke showed the group a picture of a mockernut tree in one of his fields which he had girdled to kill it. The tree lived four years and during those years the moisture had to go up through the inner wood.
The substance of Mr. Stoke's talk, together with illustrations, may be found on page 99 of the 1946 report.