I have spent more of my time cultivating black walnuts than any other kind of nut tree and given more of my ground area over to them. Yet it was with no great amount of enthusiasm that I started working with these trees. Obviously there could be nothing new or extraordinary resulting from my planting trees of this species either on my farm or at my St. Paul home, since there already were mature, bearing black walnut trees at both places. It was only with the idea that they would be an attractive addition to the native butternut groves that I decided to plant some black walnut seedlings.

This did not prove feasible as I first attempted it. I had engaged a Mr. Miller at St. Peter to procure wild black walnut trees for me since they grew near that town. He was to dig these trees with as much of the root system included as possible and ship them to my farm. But the winter season came before this had been accomplished and both Mr. Miller and I, deciding the idea was not as practical as we had hoped it would be, abandoned it. Later that same autumn I found that a nursery just outside of St. Paul had several rows of overgrown black walnut trees which they would sell me quite reasonably. I bought them and sent instructions to the tenant at my farm to dig twenty-eight large holes in which to plant them. Packed in straw and burlap, the trees weighed about 500 pounds, I found. This was much too heavy and cumbersome to pack in my old touring car, so I hunted around for some sort of vehicle I could attach to my car as a trailer. In an old blacksmith shop, I came upon an antiquated pair of buggy wheels. They looked as though they were ready to fall apart but I decided that with repairs and by cautious driving, they might last out the trip of thirty-five miles. So I paid the blacksmith his asking price—twenty-five cents. The spokes rattled and the steel tires were ready to roll off their wooden rims but the axles were strong. My father-in-law and I puttered and pounded, strengthened and tightened, until we felt our semi-trailer was in good-enough order. It might have been, too, if the roads in the country hadn't been rough and frozen so hard that they hammered on the solid, unresisting tires and spokes until, almost within sight of the farm, one wheel dismally collapsed. As the wheel broke, the trailer slid off the road into a ditch, so that it was necessary to send on to the farm for the plow horses to haul out the car, the trailer and the trees. The horses finished hauling the trees to that part of the farm where holes had been dug for them. I had told my tenant to dig large holes and large holes he had certainly dug! Most of them were big enough to bury one of the horses in. Such was my amateurish first endeavor.

It was not until December of that year, 1919, that the twenty-eight trees were finally planted. Although the ground was already somewhat frozen and the trees poorly planted as a result, most of them started to grow in the spring. They would probably be living now if I had not been too ambitious to convert them from seedlings into grafted varieties such as the Ohio, Thomas and Stabler, which I had learned of during a winter's study of available nut-culture lore. I obtained scionwood from J. F. Jones, part of which I put on these abused trees and the remainder of which I grafted on butternut trees. At that time, I must admit, I was much more interested in trying the actual work of grafting than I was in developing or even conceiving a methodical plan to be worked out over a period of years.

In order to facilitate my grafting work that spring, I pitched a tent in the woods and lived there for a week at a time, doing my own cooking and roughing it generally. Cows were being pastured in this part of the woods and they were very interested in my activities. If I were absent for a long time during the day, on my return I would find that noticeable damage had been done to my tent and food supplies by these curious cows. While preparing some scionwood inside the tent one day, I heard a cow approaching and picked up a heavy hickory club which I had for protection at night, intending to rush out and give the animal a proper lesson in minding its own business. The cow approached the tent from the side opposite the door and pushed solidly against the canvas with its nose and head. This so aggravated me that I jumped over to that part of the tent and gave the cow a hard whack over the nose with my hickory stick. It jumped away fast for such a big animal. This seemed to end all curiosity on the part of these cows and I was allowed to carry on my work in peace.

With beginner's luck, I succeeded with many of the butternut grafts, as well as with some of the grafts on the twenty-eight planted black walnuts. However, all of the grafted black walnut trees ultimately died with the exception of one grafted Stabler. This large tree was a monument of success for twenty years, bearing some nuts every year and maturing them, and in a good season, producing bushels of them. One other of these seedlings survived but as it would not accept any grafts, I finally let it live as nature intended.

In 1921, I began ordering grafted black walnut trees, as well as grafted hickory trees from J. F. Jones, who had the largest and best known of the nurseries handling northern nut trees. Some of these grafted trees were also planted at my home in St. Paul, using the two locations as checks against each other. The site in St. Paul eventually proved unsatisfactory because of the gravelly soil and because the trees were too crowded. The varieties of black walnuts I first experimented with were the Thomas, Ohio, Stabler and Ten Eyck, which were planted by hundreds year after year. If I had not worked on this large scale there would be no reason for me to write about it today as the mortality of these black walnuts was so high that probably none would have lived to induce in me the ambition necessary to support a plan involving lengthy, systematic experimentation. Some of these early trees survive today, however, and although few in number, they have shown me that the experiment was a worthy one since it laid the foundation for results which came later. In fact, I feel that both the time and money I spent during that initial era of learning were investments in which valuable dividends of knowledge and development are still being paid.

In grafting black walnuts on butternut trees, I very foolishly attempted to work over a tree more than a foot in diameter and I did not succeed in getting a single graft to grow on it. Other younger trees, from three to six inches in diameter, I successfully grafted. Some of these are still living but clearly show the incompatibility of the two species when black walnut is grafted on butternut. The opposite combination of butternut on black walnut is very successful and produces nuts earlier and in greater abundance than butternut does when grafted on its own species.

The expense of buying trees by hundreds was so great that after a year I decided that I could very easily plant black walnuts to obtain the young trees needed as understocks. When they had grown large enough, I would graft them over myself. I wrote to my friend in St. Peter, Mr. E. E. Miller, and he told me where I could obtain walnuts by the bushel. Soon I was making trips to the countryside around St. Peter buying walnuts from the farmers there. I planted about five bushels of these at the River Falls farm and the rest, another two bushels, at St. Paul. Soon I had several thousand young walnut trees which all proved hardy to the winters.

When pruning the black walnut trees purchased from Mr. Jones for transplanting, I saved the tops and grafted them to the young trees with a fair degree of success. In a few years, I was using my own trees to fill up spaces left vacant by the mortality of the Pennsylvania-grown trees. I did not neglect seeding to provide stocks of the Eastern black walnut also, which is almost a different species from the local black walnut, but these seedling trees proved to be tender toward our winters and only a few survived. After they had grown into large trees, these few were grafted to English walnuts. The difference between the Eastern black walnut and the local native black walnut is quite apparent when the two trees are examined side by side. Even the type of fruit is different, although I do not know of any botanical authority who will confirm my theory that they are different species. They are probably to be considered as geographically distinct rather than as botanically different species.

For several years I continued to graft black walnuts on butternut trees with the intention of converting hundreds, perhaps thousands, of these wild trees over to prolific, cultured black walnuts. I did not realize my mistake in doing this until ten years had elapsed. I believed that since the tops were growing, the trees would shortly produce nuts. Today they are still growing, bigger and better, yet most of these grafted trees bear no nuts, having only a crop of leaves. A few nuts result from these grafts, however, and some of the trees bear a handful of nuts from tops of such size that one would expect the crops to be measured in bushels. The kind which bore the best was the Ohio variety. In another chapter, I shall relate parallel experience in hickory grafting which I carried on simultaneously with grafting of black walnut on butternut.

My first big disappointment in my black walnut orchard was when, in about 1930, having a fairly good crop of nuts, I unsuccessfully attempted to sell them to local stores. They were not interested in anything except walnut kernels and to them, a wild walnut kernel was the same as a cultivated one as long as it was highly-flavored. This so cooled my enthusiasm and hopes for a black walnut orchard that I ceased experimenting with them except to try out new varieties being discovered through nut contests carried on by the Northern Nut Growers' Association. The 1926 contest produced a number of black walnut possibilities, among them being such named varieties as the Rohwer, Paterson, Throp, Vandersloot, Pearl and Adams.

The neglected and over-grown walnut seedlings now began to serve a useful purpose in grafting the new varieties which I obtained for testing in this locality. These were propagated by obtaining scionwood from the originators of the variety and grafting it on these seedling trees. My technical knowledge had increased by this time to such an extent that I was usually certain of one-half of the grafts growing. The behavior of the Rohwer and Paterson in 1937 invited nursery propagation on a greater scale than did other better-known types, because of their qualities of hardiness and earlier-ripening.

In the spring of 1937, these native seedlings were again offered to the spirit of propagation, when a large part of the scionwood of English walnuts I had imported from the Carpathian mountains of Poland was grafted on them. The success of my grafting in this instance was only about 1-1/2%, showing that something was decidedly wrong. Two conclusions were possible: Either the scionwood had been injured by transportation and the severe winter temperatures during January and February of 1937 during which they were stored, or incompatibility existed between the imported walnuts and our local ones. My conclusion now is that when these stocks are fifteen years old or more and are thrifty, they will support grafting of the Carpathian English walnuts much more successfully than they will in their first decade of growth. Results have shown that these local stocks will accept such grafts, however, and that crops of English walnuts will be produced. The fertility of the soil must be maintained carefully, since the English walnut top tends to overgrow its black walnut root-stock, and unless nutritional substance for the support of these tops is fed to the root-system, meager crops, if any, will result.

I might note in comparison to the 1-1/2% success I had in this grafting, that during the same season I put several hundred scions of these same English walnuts on the Eastern black walnut stocks without a single successful graft occurring.

In 1933 and 1934, many of these experimentally grafted walnuts, such as Vandersloot, Paterson, and Rohwer as well as others, were planted in orchard formation. In digging these trees, we took care to get all of the root possible and to take a ball of dirt with the root. In spite of these precautions, some of the trees died, not having sufficient vitality and root development to withstand transplantation. This was a result not only of the crowded condition under which the stocks had grown but also of the poor soil which had nourished them. The soil was heavy blue clay underlaid with limestone within two feet of the top of the ground. Enough trees were set out in orchard formation which are growing well and bearing annual crops, to give us the proof we need in drawing conclusions of superiority among these varieties.

Black walnuts will keep for several years if they are properly dried and then stored in a cool, but not too damp, place. Storing nuts in attics which are likely to become excessively hot in the summer time, causes rancidity sooner than any other method. Nuts keep very well in attics during the winter but they should be transferred to a basement during hot weather. If the basement is very damp, though, nuts will mould there. For general storage, without having to move them from one place to another for different seasons, nuts can be kept most practically in a barn or outside shed. The only precaution necessary under such circumstances is that they should be in a box or steel barrel to prevent squirrels and mice from feeding on them, since barns and sheds are easily accessible to these animals.

The kernels of black walnuts need not be discolored if the hulls of the fresh nuts are removed as soon as the nuts are ripe. At my farm, we have done this with an ordinary corn-sheller. The nuts, having been hulled this way, are then soaked in water for a few hours to remove any excess coloring matter left on their shells, after which they are dried for several days out-of-doors, although not exposed to the sun since this might cause them to crack open. Thorough drying is necessary before sacking to prevent moulding. Kernels extracted from nuts treated this way are very light in color like English walnuts. This enhances their market value and they command a higher price when they are to be used for culinary purposes such as cake frosting and candies where there is exposure of large pieces or halves of the nut kernel. I find black walnuts are exceptionally delicious when used in a candy called divinity fudge. The strong flavor of the black walnut kernel although appreciated by many people, is not as popular as that of the butternut, of which more is said in another chapter.

The food value of black walnut kernels is high since they are composed of concentrated fat and protein, similar to the English walnut, the hickory nut and the pecan. There is also the advantage, which John Harvey Kellogg of Battle Creek, Michigan, has pointed out, that nuts are a food of high purity being entirely free from disease bacteria. One could safely say of unshelled nuts that there is not a disease germ in a carload.

There was a time when black walnut hulls were purchased by producers of insecticides. The black walnut hull, when dried and pulverized, produces a substance which gives body to the concentrated pyrethrum extract which is the essential ingredient of many insecticides.

One cannot leave a discussion of black walnuts without reflecting on the furniture which has been possible only through the use of vast forests of black walnut timber. Beautiful veneers have come from the burl walnut, being formed by protuberances on the trunks of the trees near the surface of the ground. There is a variety of black walnut which we have been experimenting with for quite a few years, called the Lamb, which has a beautifully figured grain. As this appears only in mature timber, ours is not yet old enough to show it.

I have found that the Ohio black walnut is prone to hybridize with butternut trees in its vicinity and others have told me of its hybridizing with English walnut trees near it, which shows it to be almost as vacillating in character as our Japanese walnuts or heartnuts. Ohio black walnuts, when planted, usually produce vigorous stocks, many of which show hybridity of some sort. If one examines the nuts of the Ohio and finds them dwarfed or deformed, he may be sure that they have been pollinized by something other than a black walnut. Planting such nuts, then, will grow hybrid trees. Most of us have enough curiosity to want to try this as an experiment.

Thomas walnut seedlings have produced more thrifty trees than Ohio nuts have. However, the best understocks are those produced from seeds of native grown trees. It is well understood that rarely does a specific type such as the Ohio, Thomas or Stabler reproduce itself exactly from seeds. In raising black walnut seedlings, my experience has taught me that the nuts should be planted in the fall and not too deep, one to two inches below the surface being all the depth necessary. They may never sprout if they are four to six inches under ground. The black walnut tree is a glutton for food seemingly, it will use all the fertilizer that it is given although, no doubt, there is a practical limit. It must have plenty of food to produce successive crops of nuts, and barnyard manure is the safest and most practical kind to use. This can be put on as a heavy mulch around the trees but some of it should also be spaded into the ground. One must always remember that the feeding roots of a tree are at about the same circumference as the tips of the branches so that fertilizer put close to the trunk will do little good except in very young trees. Since 1936 we have been watching a small native walnut which came into bearing while in a nursery row. This tree bore such fine thin-shelled easy-to-crack nuts and lent itself so readily to being propagated by graftage and had so many other good characteristics that we have selected it as representative of the black walnut varieties for the north and have named it the Weschcke walnut and patented the variety. A list is here appended to show the order of hardiness and value based on our experience:

1—Weschcke—very hardy—excellent cracking and flavor

2—Paterson—very hardy—excellent cracking and flavor (originating in Iowa)

3—Rohwer—very hardy—good cracker (originating in Iowa)

4—Bayfield—very hardy—good cracker (originating in Northern Wisconsin)

5—Adams (Iowa)—fairly hardy—good cracker

6—Ohio—semi-hardy, excellent cracking and flavor (parent tree in Ohio)

7—Northwestern—a new, good hardy nut

8—Pearl—semi-hardy—good (from Iowa)

9—Vandersloot—semi-hardy—very large

10—Thomas—tender to our winters—otherwise very good (from Pennsylvania)

11—Stabler—tender—many nuts single-lobed

12—Throp—tender, many nuts single-lobed