GROWING NUTS IN THE NORTH
A personal story of the author's experience of 33 years with nut culture in Minnesota and Wisconsin. Includes his failures as well as final successes.
Scientific as well as readable for the amateur horticulturist with many illustrations. Tells how to grow and to propagate nut bearing trees and shrubs.
By CARL WESCHCKE
WEBB PUBLISHING CO.
ST. PAUL, MINNESOTA, U.S.A.
ST. PAUL, MINNESOTA
GROWING NUTS IN THE NORTH
Only a few books have been written on the subject of nut trees and their bearing habits, and very little of that material applies to their propagation in cold climates. For these reasons I am relating some of the experiences I have had in the last thirty-two years in raising nut trees in Wisconsin. To me, this has been a hobby with results both practical and ornamental far beyond my original conception. I hope that the information I am giving will be of help and interest to those who, like myself, enjoy having nut-bearing trees in their dooryards, and that it will prevent their undergoing the failures and disappointments I sometimes met with in pioneering along this line. Since my purpose is to give advice and assistance to those whose interest parallels mine by relating my successes and failures and what I learned from each, I have included only those details of technique which are pertinent.
It is a fine thing to have a hobby that takes one out-of-doors. That in itself suggests healthful thought and living. The further association of working with trees, as with any living things, brings one into the closest association with nature and God. I hope this book may help someone achieve that attitude of life, in which I have found such great pleasure and inner satisfaction.
Anyone wishing to make a planting of a few nut trees in his dooryard or a small orchard planting should join the Northern Nut Growers' Association. This Association can be joined by writing the current secretary, but since that office may be changed from time to time, persons applying for membership should write George L. Slate of Geneva Experiment Station, Geneva, New York, or Dr. H. L. Crane, Principal Horticulturist, U. S. Department of Agriculture, Bureau of Plant Industry, Beltsville, Maryland, or the Author. The first president was Dr. Robert T. Morris, New York City, N. Y., 1910-1911, the Association being founded by Dr. W. C. Deming of Westchester, New York, who called the first meeting in 1910.
Each year a report was printed of the proceedings of the Annual Meeting and exclusive of the 1952 meeting, the Reports which are in substantial book form number forty-two. Most of these Reports can be obtained by writing to the secretary, the total library of these Reports constituting one of the best authorities for nut tree planting in the northern hemisphere of the United States than any extant.
The author acknowledges with thanks the consistent encouraging praise from his father, Charles Weschcke, of the work involved in nut growing experiments, also for his financial assistance, thus making the publication of this book possible and available to readers at a nominal price.
The editor of the greater part of this book, Allison Burbank Hartman (a descendent of the great Luther Burbank), is entitled to great praise and thanks for the interest and work she put forth.
Grateful acknowledgment is made to William Kuehn, the artist. He had been associated with the author in Boy Scout work, also became a part of the nut growing experiments in Northern Wisconsin, which work was interrupted by World War II.
Acknowledgment is hereby made with gratitude to Dr. J. W. McKay of the U. S. Department of Agriculture, Washington, D. C.; Harry Weber of Cincinnati, Ohio; Ford Wilkinson, Rockport, Ind.; Fayette Etter, Lehmasters, Pa.; Dr. W. C. Deming, Litchfield, Conn.; Clarence A. Reed, Washington, D. C.; Dr. J. Russell Smith, Swarthmore, Pa.; George S. Slate, Urbana, Ill.; Herman Last, Steamboat Rock, Iowa, and many other professors and horticulturists who lent their time and effort assisting me in my experiments throughout the years. And last but not least, the author is indebted to his secretary, Dorothy Downie, for tireless efforts in re-writing the manuscript many times which was necessary in compiling this book.
GROWING NUTS IN THE NORTH
Chapter 1 First Encounters
Chapter 2 First Attempts
Chapter 3 Black Walnuts
Chapter 4 Hazels and Filberts
Chapter 5 Hazels and/or Filberts
Chapter 6 Pecans and Their Hybrids
Chapter 7 Hickory the King
Chapter 8 Butternut
Chapter 9 Pioneering With English Walnuts in Wisconsin
Chapter 10 Other Trees
Chapter 11 Pests and Pets
Chapter 12 Storing and Planting Seeds
Chapter 13 Tree Planting Methods
Chapter 14 Winter Protection of Grafts and Seedlings
Chapter 15 Tree Storage
Chapter 16 Suggestions on Grafting Methods
Chapter 17 Grafting Tape Versus Raffia
Chapter 18 Effects of Grafting on Unlike Stocks
Chapter 19 Distinguishing Characteristics of Scions
Chapter 20 Hybridizing
Chapter 21 Toxicity Among Trees and Plants
Almost everyone can remember from his youth, trips made to gather nuts. Those nuts may have been any of the various kinds distributed throughout the United States, such as the butternut, black walnut, beechnut, chestnut, hickory, hazel or pecan. I know that I can recall very well, when I was a child and visited my grandparents in New Ulm and St. Peter, in southern Minnesota, the abundance of butternuts, black walnuts and hazels to be found along the roads and especially along the Minnesota and Cottonwood river bottoms. Since such nut trees were not to be found near Springfield, where my parents lived, which was just a little too far west, I still associate my first and immature interest in this kind of horticulture with those youthful trips east.
The only way we children could distinguish between butternut and black walnut trees was by the fruit itself, either on the tree or shaken down. This is not surprising, however, since these trees are closely related, both belonging to the family Juglans. The black walnut is known as Juglans nigra and the butternut or white walnut as Juglans cinera. The similarity between the trees is so pronounced that the most experienced horticulturist may confuse them if he has only the trees in foliage as his guide. An experience I recently had is quite suggestive of this. I wished to buy some furniture in either black walnut or mahogany and I was hesitating between them. Noting my uncertainty, the salesman suggested a suite of French walnut. My curiosity and interest were immediately aroused. I had not only been raising many kinds of walnut trees, but I had also run through my own sawmill, logs of walnut and butternut. I felt that I knew the various species of walnut very thoroughly. So I suggested to him:
"You must mean Circassian or English walnut, which is the same thing. It grows abundantly in France. You are wrong in calling it French walnut, though, because there is no such species."
He indignantly rejected the name I gave it, and insisted that it was genuine French walnut.
"Perhaps," I advised him, "that is a trade name to cover the real origin, just as plucked muskrat is termed Hudson seal."
That, too, he denied. We were both insistent. I was sure of my own knowledge and stubborn enough to want to prove him wrong. I pulled a drawer from the dresser of the "French walnut" suite and asked him to compare its weight with that of a similar drawer from a black walnut suite nearby. Black walnut weighs forty pounds per cubic foot, while butternut weighs only twenty-five. He was forced to admit the difference and finally allowed my assertion to stand that "French walnut" was butternut, stained and finished to simulate black walnut. Since it would have been illegal to claim that it was black walnut, the attractive but meaningless label of "French walnut" had been applied. Although it is less expensive, I do not mean to imply that butternut is not an excellent wood for constructing furniture. It ranks high in quality and is probably as durable as black walnut. I do say, though, that it was necessary for me to know both the species names and the relative weights of each wood to be able to distinguish between them indisputably.
An instance in which the nuts themselves were useless for purposes of identification occurred when I sent some black walnuts to the Division of Pomology at Washington, D. C. These were the Ohio variety which I had grafted on butternut roots. The tree had been bearing for three or four years but this was the first year the nuts had matured. During their bearing period, these black walnuts had gradually changed in appearance, becoming elongated and very deeply and sharply corrugated like butternuts although they still retained the black walnut flavor. Because of this mixture of characteristics, the government experts had great difficulty in identifying the variety, although the Ohio was well known to them.
Another variety of black walnut, the Thomas, I have also known to be influenced by the butternut stock on which it was grafted, when in 1938, one of my trees bore black walnuts whose meat had lost its characteristic flavor and assumed that of the butternut.
I also liked to pick hazelnuts when I was a boy. These are probably the least interesting among the wild nuts since they are usually small and hard to crack. There is much variation in wild hazels, however, and many people may recall them as being reasonably large. One of the two species abundant in Minnesota, Corylus cornuta or Beak hazel, has fine, needle-like hairs on its husk which are sure to stick into one's fingers disagreeably. When the husk is removed, Corylus cornuta resembles a small acorn. It does not produce in southern Minnesota and central Wisconsin as well as the common hazel, Corylus Americana, does, nor is its flavor as pleasing to most people. It is lighter in color than the common hazel and has a thinner shell. Of course, some hazels are intermediate or natural hybrids between these two species, and if the nuts of such hybrids are planted, they generally revert to one of the parents when mature enough to bear. This natural hybridization occurs among all plants, between those of the same species, the same genera or the same family. It is very rare between plants of different families. The process is a very important one in horticulture and I shall explain some of the crosses which are well-known later in this book.
When I was about fifteen years old, my family moved to St. Paul, Minnesota, where my home now is and where my experimental work with nuts was begun. St. Paul is in the 45th north parallel, but although it is farther north, it is as favorable for the growth of nut trees as New Ulm or St. Peter, because it lies in the Mississippi River valley and is farther east. Bodies of water and altitudes have as great an influence on plant life as latitude; at least, they can have, and these are factors that must be understood thoroughly. Soil conditions also vitally affect plant life, particularly deep-rooted trees such as nut trees usually are. Each has its own requirements; hickory, Japanese heartnut and Persian walnuts favor an alkaline soil, which chestnuts, wanting acid will not grow in; chestnuts thrive best in a slightly acid, well-drained soil; hazels will grow in either alkaline or acid soil as will black walnuts and butternuts; almonds need a light sandy soil, similar to that suitable to plums, pecans do well in either rich river bottoms, which may be slightly acid, or in clay soil on high hillsides which are alkaline. A deep, sandy or graveltype soil is usually accepted by the chestnuts even though it may not be slightly acid, and successful orchards have been grown on a deep clay soil on hillsides.
It is not always easy to obtain black walnuts and butternuts to eat. Hickory nuts have been a favorite of mine since I first tasted them and I often have found it difficult to procure fresh ones, ones that were not slightly rancid. Because I liked eating these nuts, I thought I would try to grow some for my own consumption and so avoid having to depend on a grocer's occasional supply of those shipped in, always a little stale. Raising nuts appealed to me economically too, since obviously trees would need little care, and after they had begun to bear would supply nuts that could be sold at interesting prices.
I turned the back yard of my home in St. Paul into an experimental plot. Here I set out some of each kind of tree I planted or grafted at my farm in Wisconsin. I had purchased a farm 35 miles east of St. Paul, beyond the influence of the St. Croix River Valley. My experiments really began there. The farm was covered with butternut trees, hazel bushes, and a wild hickory called "bitternut." This last is well-named for I have never found an animal other than a squirrel that could endure its nuts. Possibly the white-footed mouse or deer-mouse could—I don't know. He usually eats anything a squirrel does. I learned to appreciate these bitternut trees later and they became a source of experience and interest to me as I learned to graft on them many varieties, species and hybrids of hickory. They served as a root-system and shortened the length of time required to test dozens of hickory types, helping me in that way, to learn within one lifetime what types of nuts are practical for growing in the north.
Remembering the nut trees in southern Minnesota, I first thought to procure black walnut and hickory trees from some farmer in that district. Through acquaintances in St. Peter, I did locate some black walnut trees only to find that it was impractical to dig and transport trees of the size I wanted. A nursery near St. Paul supplied me with some and I bought twenty-eight large, seedling black walnut trees. I was too eager to get ahead with my plans and I attempted, the first year these trees were planted, to graft all of them. My ability to do this was not equal to my ambition though, and all but two of the trees were killed. I was successful in grafting one of them to a Stabler black walnut; the other tree persisted so in throwing out its natural sprouts that I decided it should be allowed to continue doing so. That native seedling tree which I could not graft now furnishes me with bushels of walnuts each year which are planted for understocks. This is the name given to the root systems on which good varieties are grafted.
In an effort to replace these lost trees, I inquired at the University of Minnesota Farm and was given the addresses of several nurserymen who were then selling grafted nut trees. Their catalogues were so inviting that I decided it would be quite plausible to grow pecans and English walnuts at this latitude. So I neglected my native trees that year for the sake of more exotic ones. One year sufficed; the death of my whole planting of English walnuts and pecans turned me back to my original interest. My next order of trees included grafted black walnuts of four accepted varieties to be planted in orchard form—the Stabler, Thomas, Ohio and Ten Eyck.
I ordered a few hickories at the same time but these eventually died. My experience with hickories was very discouraging since they were my favorite nuts and I had set my heart on growing some. I think I should have given up attempting them had not one dealer, J. F. Jones, urged that I buy just three more hickory trees of the Beaver variety. He gave me special instructions on how to prepare them against winter. I have always felt that what he told me was indeed special and very valuable since those three trees lived. Subsequently, I bought several hundred dollars worth of trees from him. More than that, we became friends. I visited him at his nurseries in Lancaster, Pennsylvania, and he again demonstrated his interest and generosity by giving me both horticultural information and the kindest hospitality. My friendship with him was but one of many that I have formed while traveling and corresponding in the interests of nut culture. True and lasting friends such men make, too, with no circumstances of selfish import to taint the pleasure of the relationship.
Since I wanted to have many black walnut trees some day, I decided to plant ten bushels of black walnuts in rows. I thought I could later graft these myself and save expense. The theory was all right but when I came to practice it, I found I had not taken squirrels into consideration. These bushy-tailed rats dug up one complete bed which contained two bushels of nuts and reburied them in haphazard places around the farm. When the nuts started to sprout, they came up in the fields, in the gardens, and on the lawn—everywhere except where I had intended them to be. I later was grateful to those squirrels, though, because, through their redistributing these nuts I learned a great deal about the effect of soil on black walnut trees, even discovering that what I thought to be suitable was not. The trees which the squirrels planted for me are now large and lend themselves to experimental grafting. On them I have proved, and am still proving, new varieties of the English walnut.
The other eight bushels had been planted near a roadside and close to some farm buildings. The constant human activity thereabouts probably made the squirrels less bold, for although they carried off at least a bushel of walnuts, about two thousand seedlings grew. I had planted these too close together and as the trees developed they became so crowded that many died. The remaining seedlings supplied me with root-stocks for experimental work which proved very valuable.
I have always suspected the squirrels of having been responsible for the fact that my first attempt to grow hickory seedlings was unsuccessful. I planted a quart of these nuts and not one plant came up. No doubt the squirrels dug them up as soon as I planted them and probably they enjoyed the flavor as much as I always have.
In 1924 I ordered one hundred small beechnut trees, Fagus ferruginea, from the Sturgeon Bay Nurseries at Sturgeon Bay, Wisconsin. The company was very generous and sent me three hundred of them. I planted these trees in a heavy clay soil with limestone running near the surface. They grew well the first year, except that there was heavy mortality during cold weather. In working with these trees my lack of experience and horticultural knowledge was against me. They could not tolerate the soil and within three years they were all dead.
To give variety to the landscape at my farm, I planted several other kinds of trees. Among these were Kentucky coffee-trees which have beautiful bronze foliage in the spring and honey locusts. I planted five hundred Douglas fir but unfortunately, I put these deep in the woods among heavy timber where they were so shaded that only a few lived. Later, I moved the surviving fir trees into an open field where they still flourish. About two hundred fifty pines of mixed varieties—white, Norway and jack—that I planted in the woods, also died.
I decided, then, that evergreens might do better if they were planted from seeds. I followed instructions in James W. Toumey's "Seeding and Planting in the Practice of Forestry," in bed culture and spot seeding. In the latter one tears off the sod in favorable places and throws seed on the unprotected ground. In doing this, I ignored the natural requirements of forest practice which call for half-shade during the first two to three years of growth. Thousands of seedlings sprouted but they all died either from disease or from attacks by cows and sheep. One should never attempt to raise trees and stock in the same field.
Because of these misfortunes, I determined to study the growth of evergreens. I invested in such necessary equipment as frames and lath screening. Better equipped with both information and material, I grew thousands of evergreen trees. Among the varieties of pine were:
native White Pine —Pinus strobus Norway pine —Pinus silvestrus Mugho pine —Pinus pumila montana sugar pine —Pinus Lambertiana (not hardy in northern Wisconsin) Swiss stone —Pinus cembra (not hardy in northern Wisconsin) Italian stone —Pinus pinea (not hardy in northern Wisconsin) pinon —Pinus edulis (not hardy in northern Wisconsin) bull pine —Pinus Jeffreyi (hardy) jack pine —Pinus banksiana (very hardy) limber pine —Pinus flexilis (semi-hardy, a fine nut pine).
Many of the limber pines came into bearing about fifteen years after the seed was planted. At that age they varied in height from three to fifteen feet. One little three-foot tree had several large cones full of seed. Each tree varied in the quality and size of its seeds. Although it might be possible to graft the best varieties on young seedling stocks, in all the hundreds of grafts I have made on pine, I have been successful only once. I doubt that such a thing would ever be practical from a commercial standpoint unless some new method were discovered by which a larger percentage of successful grafts could be realized.
I cultivated the Douglas fir, white, Norway, and Colorado blue varieties of spruce. Besides these, I planted balsam fir, red cedar, Juniperus Virginiana, and white cedar, Arborvitae. Practically all of these trees are still growing and many of them bear seed.
I wish to describe the limber pine, Pinus flexilis, for it is not only a good grower and quite hardy but it is also a very ornamental nut pine which grows to be a broad, stout-trunked tree 40 to 75 feet high. The young bark is pale grey or silver; the old bark is very dark, in square plates. The wood itself is light, soft and close-grained, having a color that varies from yellow to red. The needles, which are found in clusters of five, are slender, 1-1/2 to 3 inches long, and are dark green. They are shed during the fifth or sixth year. The buds of the tree are found bunched at the branch tips and are scaly and pointed. The limber pine has flowers like those of the white pine, except that they are rose-colored. Although the fruit is described as annual, I have found that, in this locality, it takes about fifteen months from the time the blossoms appear for it to reach maturity. That is, the fruit requires two seasons for growth, maturing its seeds the second September. The cones of the limber pine, which vary from three to seven inches in length, are purple, having thick rounded scales and being abruptly peaked at the apex. The seeds are wingless or have only very narrow wings around them.
With the idea of getting practical results sooner, since nut trees mature slowly, I interplanted my nut trees with varieties of apple, plum and cherry. Doing so also served to economize on ground, since ultimately nut trees require a great deal of space for best growth. Walnut trees, for example, should be set 40 to 60 feet apart in each direction.
I learned a variety of facts during these first years of trial and error. I discovered, for instance, that iron fence posts rust away in an acid soil; that one must use cedar or oak. Conversely, in alkaline soil, iron will last indefinitely, but that the nitrogenous bacteria will quickly rot wooden posts. I found that the secret of growing hickories successfully lies in giving them plenty of room, with no forest trees around to cut off their supply of sunlight and air. I learned that it is impractical to graft a large forest tree of butternut or hickory. Incidental to that, I learned that a branch of a butternut tree which looks large enough to support a man's weight near the trunk, will not do so when the branch is green and alive, but that a dead branch of similar size will. Contrariwise, even a small green limb of a bitternut-hickory will bear my weight, but an old limb, though several inches thick, becomes so brittle after it is dead for several years that it will break under slight pressure. Fortunately, falls from trees do not usually result in serious injuries but I did acquire quite a few bruises learning these distinctions.
There is always a natural mortality in planting trees, but in those first years, lacking badly-needed experience, I lost more than 75%. Nearly all of them started to grow but died during the first few winters. Those which survived were the start of a nursery filled with hardy trees which can endure the climate of the north. In looking back, I appreciate how fortunate I was in having sought and received advice from experienced nurserymen. Had I not done so, frequent failures would surely have discouraged me. As it was, the successes I did have were an incentive which made me persist and which left me with faith enough in an ultimate success to go on buying seeds and trees and to make greater and more varied experiments.
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)
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
A friend of mine, who lives in Mason, Wisconsin, discovered a black walnut tree growing in that vicinity. Since Mason is in the northern part of the state, about 47 deg. parallel north, this tree grows the farthest north of any large black walnut I know of. I would estimate its height at about sixty-five feet and its trunk diameter at about sixteen inches at breast-height. Because of the short growing season there, the nuts do not mature, being barely edible, due to their shrinkage while drying. Some seasons this failure to mature nuts also occurs in such varieties as the Thomas, the Ohio and even the Stabler at my River Falls farm, which is nearly 150 miles south of Mason. Such nuts will sprout, however, and seedlings were raised from the immature nuts of this northern tree. Incidentally these seedlings appear to be just as hardy in wood growth as their parent tree. I have also grafted scionwood from the original tree on black walnut stocks at my farm in order to determine more completely the quality of this variety. Since grafted, these trees have borne large, easy to crack mature nuts and are propagated under the varietal name (Bayfield) since the parent tree is in sight of Lake Superior at Bayfield, Wisconsin.
Many of our best nut trees, from man's point of view, have inherent faults such as the inability of the staminate bloom of the Weschcke hickory to produce any pollen whatsoever, as has been scientifically outlined in the treatise by Dr. McKay under the chapter on hickories. In the Weschcke walnut we have a peculiarity of a similar nature as it affects fruiting when the tree is not provided with other varieties to act as pollinators. It has been quite definitely established, by observation over a period of ten or more years, that the pollen of the Weschcke variety black walnut does not cause fruiting in its own pistillate blooms. Although this is not uncommon among some plants, such as the chestnut and the filbert where it is generally the rule instead of the exception, yet in the black walnuts species the pollen from its own male (or staminate) flowers is generally capable of exciting the ovule of the female (pistillate) flower into growth. Such species are known as self-fertile. As in the case of ordinary chestnuts which receive no cross pollination, and the pistillate flowers develop into perfect burrs with shrunken meatless, imperfect nuts, the Weschcke black walnut, when standing alone or when the prevailing winds prevent other nearby pollen from reaching any or but few of its pistillate bloom, goes on to produce fine looking average-sized nuts practically all of which are without seed or kernels. Such therefore is the importance of knowing the correct pollinators for each variety of nut tree. In the self-sterility of filberts the failure of self-pollination results in an absence of nuts or in very few rather than a full crop of seedless fruits such as the common chestnut and the Weschcke black walnuts produces. This is the only black walnut that has come to the author's attention where its pollen acting on its pistillate bloom has affected the production of nuts in just this way but the variety of black walnut known as the Ohio, one of the best sorts for this northern climate except for hardiness, has often demonstrated that it has a peculiarity which might be caused by lack of outside pollen or because of the action of its own pollen on its pistillate bloom. This peculiarity is the often found one-sided development of the Ohio walnut kernel when the tree is isolated from other pollen bearing black walnuts. One lobe of the kernel is therefore full-meated while the other half or lobe is very undernourished or it may be a thin wisp of a kernel as is the appearance of the Weschcke variety in similar circumstances.
Cutting scionwood early one spring, I noticed that the sap was running very fast in the grafted Stabler tree previously referred to. Later when I came back to inspect this tree, I noticed that the sap had congealed to syrupy blobs at the ends of the cut branches. My curiosity led me to taste this and I found it very sweet and heavy. I mean to experiment some time in making syrup from the sap of this tree as I believe its sugar content to be much higher than that of the local sugar maple. This makes the Stabler a 3-purpose tree, the first being its nuts, the second being the syrup, and the third being, at the end of its potentially long life, a good-sized piece of timber of exceptionally high value. The tree is one of beauty, having drooping foliage similar to that of the weeping willow. This is another point in its favor, its being an ornamental tree worthy of any lawn. However, the Stabler is now considered as a tender variety and is not recommended for northern planting.
The aesthetic value of the black walnut does not cease here since there are some varieties which are exceptionally attractive. One of these is the cut-leaf black walnut which has the ordinary compound leaf but whose individual leaflets are so scalloped and serrated that they resemble a male fern. Everyone who has seen one of these has evinced pleasurable surprise at this new form of leaf and it may become very popular with horticulturists in the future. Another interestingly different variety is the Deming Purple walnut which, although orthodox in leaf form, has a purplish tint, bordering on red in some cases, coloring leaf, wood and nuts, resulting in a distinctly decorative tree. This tree was named for Dr. W. C. Deming who was the founder of the Northern Nut Growers' Association. Neither the Laceleaf nor Deming Purple are hardy for this climate but survived several years nevertheless before succumbing to one of our periodical test winters.
HAZELS AND FILBERTS
In October 1921, I ordered from J. F. Jones, one hundred plants of what is known as the Rush hazel which was, at that time, the best known of the propagated hazels. In ordering these, I mentioned the fact that I expected to get layered plants or grafted ones. Mr. Jones wrote me at once to say that the plants he had were seedlings of the Rush hazel which are said to come very true to seed, but that if I did not want them as seedlings he would cancel the order. Rather than lacking a profitable filler between the orchard trees, I accepted the order of one hundred plants and received from him a fine lot of hazels which took good root and began to grow luxuriantly. It was several years before any of them began to bear and when one or two did, the nuts were not hazels at all, but filberts and hybrids. In most cases these nuts were larger and better than those of the original Rush hazel.
One of these seedlings grew into a bushy tree ten or twelve feet high. For several years it bore a crop which, though meager, was composed of large, attractive nuts shaped like those of the common American hazel but very unlike the true Rush hazelnut. One year this tree began to fail and I tried to save it or propagate it by layering and sprouting seeds. Unfortunately it did not occur to me at that time to graft it to a wild hazel to perpetuate it. I still lament my oversight as the tree finally died and a very hardy plant was lost which was apparently able to fertilize its own blossoms.
I ordered four Winkler hazel bushes from Snyder Bros. of Center Point, Iowa, in March 1927, asking them to send me plants that were extra strong and of bearing size. I planted these that spring but the following summer was so dry that all four died. I ordered twelve more Winklers in September for spring delivery, requesting smaller ones this time (two to three feet). Half of these were shipped to me with bare roots, the others being balled in dirt for experimental purposes. Four of the latter are still living and producing nuts.
In April 1928, I planted a dozen Jones hybrid hazels but only two of them survived more than two years. I think the reason they lasted as well as they did was that around each plant I put a guard made of laths four feet high, bound together with wire and filled with forest leaves. I drove the laths several inches into the ground and covered them with window screening fastened down with tacks to keep mice out of the leaves. Although somewhat winter-killed, most of the plants lived during the first winter these guards were used. The second winter, more plants died, and I didn't use the guards after that.
The two Jones hybrids that lived produced flowers of both sexes for several years but they did not set any nuts. One day while reading a report of one of the previous conventions of the Northern Nut Growers' Association, I discovered an article by Conrad Vollertsen in which he stressed the importance of training filberts into a single truncated plant, allowing no root sprouts or suckers to spring up since such a condition prevents the bearing of nuts. I followed his advice with my two Jones hybrids and removed all surplus sprouts. This resulted in more abundant flowers and some abortive involucres but still no nuts developed. In the spring of 1940, I systematically fertilized numerous pistillate flowers of these plants with a pollen mixture. On the branches so treated, a fairly good crop of nuts similar to those of the orthodox Jones hybrid appeared.
I had cut off a few branches from the Jones hybrids when I received them and grafted these to wild hazels. This had been suggested by Robert Morris in his book, "Nut Growing," as an interesting experiment which might prove to be practical. It did not prove to be so for me for although the grafting itself was successful I found it tiresome to prune, repeatedly, the suckers which constantly spring up during the growing period and which are detrimental to grafts. Although they lived for five years, these grafts suffered a great deal of winter-injury and they never bore nuts. The one which lived for the longest time became quite large and overgrew the stock of the wild hazel. This same plant produced both staminate and pistillate blossoms very abundantly for several seasons but it did not set any nuts in spite of the many wild hazels growing nearby which gave it access to pollen. It is now known that this hybrid is self-sterile and must have pollinators of the right variety in order to bear.
My next work with members of the genus Corylus was discouraging. In April 1929, I bought one hundred hazel and filbert plants from Conrad Vollertsen of Rochester, New York, which included specimens of the Rush hazel and of the following varieties of filberts:
Italian Red Merribrook Kentish Cob Early Globe Zellernuts White Lambert Althaldensleben Medium Long Bony Bush Large Globe Minnas Zeller Marveille de Bollwyller
Although many of these filberts bore nuts the first year they were planted, within two years they were all completely winter-killed.
In 1932, I received ten filbert bushes from J. U. Gellatly of West Bank, British Columbia. These consisted of several varieties of Glover's best introductions and some Pearson seedlings. I planted them on the south side of a high stone wall, a favorable location for semi-hardy plants. They appeared to be thrifty and only slightly winter-killed during the first two years but by 1939, all but two of the bushes had died or were dying. Although as nut-bearing plants they have been of little value to me, their pollen has been of great service.
I found an unusually fine wild hazel growing in the woods on my farm and in 1934, I began an experiment in hybridizing it. I crossed the pistillate flowers of the native hazel with pollen from a Gellatly filbert and obtained four hybrid plants, which I have called hazilberts. In the spring of 1940, three of these hybrids had pistillate flowers but no staminate blooms. As I was very eager to see what the new crosses would be like, I fertilized the blossoms with a gunshot mixture of pollen from other plants such as the Winkler hazel, the European filbert and the Jones hybrid hazel. Certain difficulties arose in making these hybrids, mainly due to the curiosity of the squirrels who liked to rip open the sacks covering the blossoms which were being treated. Deer mice, too, I found, have a habit of climbing the stems of hazel bushes and gnawing at the nuts long before they are mature enough to use for seed. Later I learned to protect hybrid nuts by lacing flat pieces of window screening over each branch, thus making a mouse-proof enclosure. Even after gathering the nuts I discovered that precautions were necessary to prevent rodents from reaching them. The best way I found to do this is to plant nuts in cages of galvanized hardware cloth of 2 by 2 mesh, countersunk in the ground one foot and covered completely by a frame of the same material reinforced with boards and laths.
The most interesting hazilbert that has developed bears nuts of outstanding size, typically filberts in every detail of appearance, although the plant itself looks more like a hazel, being bushy and having many suckers. After more testing, this hybrid may prove to be a definite asset to nursery culture in our cold northern climate, fulfilling as it does, all the requirements for such a plant. The second hazilbert resembles the first closely except that its nuts, which are also large, are shaped like those of Corylus Americana. The third hazilbert has smaller nuts but its shell is much thinner than that of either of the others.
In reference to the hazilberts, I am reminded of certain correspondence I once had with J. F. Jones. He had sent me samples of the Rush hazel and although I was impressed by them, I mentioned in replying to him that we had wild hazels growing in our pasture which were as large or larger than the Rush hazelnuts. I admitted that ours were usually very much infested with the hazel weevil. Mr. Jones was immediately interested in wild hazels of such size and asked me to send him samples of them. He wrote that he had never seen wild hazels with worms in them and would like to learn more about them. I sent him both good and wormy nuts from the wild hazel bush to which I had referred. He was so impressed by them that he wished me to dig up the plant and ship it to him, writing that he wished to cross it with filbert pollen as an experiment. I sent it as he asked but before he was able to make the cross he intended, his death occurred. Several years later, his daughter Mildred wrote to me about this hazel bush, asking if I knew where her father had planted it. Unfortunately I could give her no information about where, among his many experiments, this bush would be, so that the plant was lost sight of for a time. Later Miss Jones sent me nuts from a bush which she thought might be the one I had sent. I was glad to be able to identify those nuts as being, indeed, from that bush.
In the spring of 1939, I crossed the Winkler hazel with filbert pollen; the European hazel with Winkler pollen; the Gellatly filbert with Jones hybrid pollen. These crosses produced many plants which will be new and interesting types to watch and build from. I have already made certain discoveries about them. By close examination of about forty plants, I have been able to determine that at least five are definitely hybrids by the color, shape and size of their buds. This is a very strong indication of hybridity with wild hazel or Winkler. On one of these plants, about one-foot high, I found staminate bloom which I consider unusual after only two seasons' growth.
During the fall of 1941, I became interested in a phenomenon of fruit determination previous to actual fructification of the plant by detailed examinations of its buds. I noticed, for instance, that large buds generally meant that the plant would produce large nuts and small buds indicated small nuts to come. The color of the buds, whether they were green, bronze green or reddish brown, could be fairly well depended upon to indicate their hybridity in many cases. These tests were not wholly reliable but the percentage of indication was so high that I was tempted to make predictions.
At that time, hazilbert No. 1 had not borne nuts. The bush resembled a wild hazel so much that I had begun to doubt its hybridity. Upon examining its buds, I found indications in their color that it was a hybrid, although the nuts apparently would not be large. It would be an important plant to me only if its pollen should prove to be effective on the other hazilberts. At the time this was only a wishful hope, because the pollen of the wild hazel, which this plant resembles, apparently does not act to excite the ovules of either filberts or filbert hybrids with filbert characteristics. Pure filbert pollen seemed to be necessary. In 1942, its pollen did prove to be acceptable to the other hazilberts and my hope for a good pollinizer was realized in it.
From the conclusions I reached through my study of the buds, I made sketches of which I believed the nuts of No. 1 would be like in size and shape. In March 1942, these sketches were used as the basis of the drawing given here. A comparison of this drawing with the photograph taken in September 1942, of the actual nuts of hazilbert No. 1 show how accurate such a predetermination can be.
I am convinced from the work I have done and am still doing, that we are developing several varieties of hazilberts as hardy and adaptable to different soils as the pasture hazel is, yet having the thin shell and the size of a European filbert. As to the quality of the kernel of such a nut, that of the wild hazel is as delicious as anyone could desire.
HAZELS AND/OR FILBERTS
There is a certain amount of confusion in the minds of many people regarding the difference between filberts and hazels, both of which belong to the genus Corylus. Some think them identical and call them all hazels dividing them only into European and American types. I see no reason for doing this. "Filbert" is the name of one species of genus Corylus just as "English walnut" is the commercial name of one of the members of the Juglans family. There is as much difference between a well-developed filbert and a common wild hazelnut as there is between a cultivated English walnut and wild black walnut.
For ordinary purposes the nuts sold commercially, whether imported or grown in this country, are called filberts while those nuts which may be found growing prolifically in woodlands and pastures over almost the whole United States but which are not to be found on the market are called hazelnuts. This lack of commercialization of hazelnuts should be recognized as due to the smallness of the nut and the thickness of its shell rather than to its lacking flavor. Its flavor, which seldom varies much regardless of size, shape or thickness of shell, is both rich and nutty. The three main food components of the hazelnut, carbohydrate, protein and oil, are balanced so well that they approach nearer than most other nuts the ideal food make-up essential to man. The English walnut contains much oil and protein while both chestnuts and acorns consist largely of carbohydrates.
One salient feature which definitely separates the species Corylus Americana or wild hazel, from others of its genus, is its resistance to hazel blight, a native fungus disease of which it is the host. Controversies may occur over the application of the names "hazel" and "filbert" but there is no dispute about the effect of this infection on members of genus Corylus imported from Europe. Although there is wide variety in appearance and quality within each of the species, especially among the European filberts, and although filberts may resemble hazels sufficiently to confuse even a horticulturist, the action of this fungus is so specific that it divides Corylus definitely into two species. Corylus Americana and Corylus cornuta, through long association, have become comparatively immune to its effects and quickly wall off infected areas while filbert plants are soon killed by contact with it. Hybrids between filberts and hazels will usually be found to retain some of the resistance of the hazel parent.
The ideal nut of genus Corylus should combine qualities of both hazels and filberts. Such a hybrid should have the bushy characteristics of the American hazel with its blight-resisting properties and its ability to reproduce itself by stolons or sucker-growth. It should bear fruit having the size, general shape, cracking qualities and good flavor of the filbert as popularly known. The hybrids I am growing at my farm, which I call "hazilberts" and which are discussed later, seem to fulfill these requirements. The plants may be grown as bushes or small trees. They are blight-resistant and their nuts are like filberts in appearance. Three varieties of these hazilberts have ivory-colored kernels which are practically free of pellicle or fibre. They have a good flavor.
A comparison of the ripening habits and the effect of frost on the various members of the genus Corylus growing in my nursery in the fall of 1940, is shown by these extracts taken from daily records of the work done there. It should be noted that the summer season that year was rainy and not as hot as usual, so that most nuts ripened two to three weeks later than they normally do.
"September 7 and 8: Wild hazels ripe and picked at this time. (Their kernels showed no shrinkage by October 25.)
September 14 and 15: I picked ripe nuts from hazilbert No. 5 which seems to be the first to ripen. Also picked half of the European filberts. (There was slight shrinkage in the kernels of the latter a few weeks later showing that they could have stayed on the trees another week to advantage.)
All of the nuts of a Jones hybrid, which is a cross between Rush and some European variety such as Italian Red, could have been picked as they were ripe. Some were picked.
The almond-shaped filbert classified as the White Aveline type, was not quite ripe; neither were hazilberts No. 2 and No. 4, nor the Gellatly filberts. Wild hazelnuts at this time had dry husks and were falling off the bushes or being cut down by mice.
September 21 and 22: The remaining European filberts of the imported plants were picked. Also, I picked half of the White Aveline type nuts.
September 28 and 29: We picked most of the nuts remaining on hazilbert No. 5 and the remainder of the White Aveline type. At this time we record a heavy frost which occurred during the previous week, that is, between September 22 and 28th. Since it froze water it was considered a "killing" frost. However, the damage was spotty all over the orchard, most things continuing to develop and ripen. Winkler hazels picked and examined at this time showed them far from ripe. Hazilberts growing next to limestone walls on the south side showed no signs of frost damage whereas the Winkler, on higher ground, showed severe damage to the leaves and the husks of the nuts which immediately started to turn brown. Leaves of other filbert plants in the vicinity showed no frost damage and the very few nuts that had been left on, such as those of the Jones hybrid, were undamaged.
October 5 and 6: Picked all of hazilbert No. 2 except the last two nuts.
Gellatly filberts were picked about October 10 and were ripe at that time.
October 11 to 13: Two English walnuts were picked and found to be as ripe as they would get. These as well as the black walnuts showed distinct signs of lacking summer heat needed for their proper development. The last two nuts on hazilbert No. 2 and the only nut on hazilbert No. 4 were picked at this time and were ripe. Chestnut burrs had opened up and the nuts enclosed were fully mature.
October 19 and 20: I found the last of the Winkler hazelnuts had been picked during the previous week, approximately October 14. These were left the longest on the bush of any hazel and still were not ripe although they were not entirely killed by the several frosts occurring before that time. They are always much later than the wild hazel."
On October 20, I had an opportunity of comparing the action of frost on the leaves of these plants. Those of the White Aveline type had not changed color and were very green. The leaves of the Jones hybrid showed some coloration but nothing to compare with those of the Winkler hazel, many of which had the most beautiful colors of any of the trees on the farm—red, orange and yellow bronze. Hazilbert No. 1, which resembles a wild hazel in appearance and habits of growth, had colored much earlier in reaction to the frost and was as brightly tinted as the wild hazel and Winkler plants except that, like the wild hazel, it had already lost much of its foliage. Some of the wild hazels were entirely devoid of leaves at this time. Hazilbert No. 5 showed the best color effects with No. 4 second and No. 2 last.
The color of the leaves and the action of the frost on the plants during the autumn is another thing, in my opinion, that helps to differentiate between and to classify European filberts, American hazels and their hybrids. My conclusion in regard to the effect of frost is that the reaction of the Winkler hazel is very similar to that of the wild hazel in color but exceeding it in beauty since its leaves do not drop as soon after coloring. At this time, the leaves had not changed color on the imported European plants, the Gellatly filberts from British Columbia or the White Aveline type. They had turned only slightly on the Jones hybrid. I think an accurate idea of the general hardiness of a plant is indicated by the effect of frost and by early dropping of leaves, using the sturdy wild hazel as the limit of hardiness and assuming that its hardiness is shown by both degree of coloration and early dropping of leaves.
In noting the action of frost on the Winkler hazel, I have mentioned that it was more like that on the American hazel than on the European filberts. The Winkler has always been considered a native woodland hazel, but, although it does show several similarities to Corylus Americana, I have also noticed certain qualities which definitely suggest some filbert heritage. I have based my theory on a study of the Winkler hazels which have been bearing annually at my farm for six years, bearing more regularly, in fact, than even the wild hazels growing nearby. My comparisons have been made with wild hazels in both Minnesota and Wisconsin and with European filberts.
I found the first point of similarity with the filbert is in the involucre covering the nut. In the wild hazel, this folds against itself to one side of the nut, while in the filbert it is about balanced and if not already exposing a large part of the end of the nut, is easily opened. The involucre of the Winkler hazel is formed much more like that of the filbert than that of the hazel. In Corylus Americana this involucre is usually thick, tough and watery, while in the filbert it is thinner and drier, so that while a person may be deceived in the size of a hazelnut still in its husk, he can easily tell that of a filbert. This is also true of the Winkler whose involucre is fairly thick but outlines the form of the enclosed nut. Another feature about the involucre of the Winkler which classes it with the filberts rather than the hazels is in its appearance and texture, which is smooth and velvety while that of the hazel is hairy and wrinkled.
The staminate blooms of the Winkler hazel show similarity to those of both filberts and hazels. Sometimes they appear in formation at the ends of branches, much as those of the European filberts do, in overlapping groups of three or four. Again, they may be found at regular intervals at the axis of leaf stems very much as in the case of the American hazel. The buds on the Winkler hazel are dull red which is also true of those on the hybrid hazilberts, another indication of hybridity.
The initial growth of the embryo nut is very slow in the Winkler as it is in the filbert, as contrasted with the very rapid development of the native hazel embryo which matures in this latitude about one month ahead of the Winklers and some filberts. Although Winkler nuts are shaped like hazels and have the typically thick shells of hazelnuts, their size is more that of a filbert usually three times as large as a native hazel.
During the years between 1942 and 1945 many new hybrids between filberts and hazels were produced. Four wild varieties of hazels, which had unusual characteristics such as tremendous bearing and large size nuts and others having very early maturing or very thin shelled nuts were used as the female parents in making the crosses. Pollen was obtained from other parts of the U. S. or from filbert bushes which were growing on the place. Crosses included pollen of the Barcelona, Duchilly, Red Aveline, White Aveline, Purple Aveline, the Italian Red, Daviana and several hybrids between other filberts and hazels. By 1945 the number of these plants were in the neighborhood of 2000 and by 1952 considerable knowledge had been gained as to the hardiness, blight resistance to the common hazel blight (known scientifically as cryptosporella anomala), freedom from the curculio of the hazelnuts (commonly known as the hazel weevil) and resistance to other insect pests. Also, considerable data had been accumulated by cataloging over 650 trees each year for five years; cataloging included varied and detailed studies of their growth, bearing habits, ability to resist blight, curculio and other insects, the size of the nut, the thinness of the shell and the flavor of the kernel. Several books of all this detail were accumulated in trying to nail down several commercial varieties that would be propagated from this vast amount of material. Although some bushes produced good nuts at the rate of as much as two tons to the acre, measured on the basis of space that they took up in the test orchard, the most prolific kind seemed to be the ones that had a tendency to revert to the wild hazel type. The better and thinner-shelled types, more resembling the filberts, seemed to be shy bearers so that there being a host of new plants to catalog (more than 1000) which had not indicated their bearing characteristics, we included these among the possible ideal plants we were seeking. Although there were several plants that could be considered commercial in the original group of over 650 it has been thought that the waiting of a few more years to ascertain whether there would be something better in the next 1000 plants to bear that would be worthwhile waiting for and no attempt has been made to propagate the earlier tested plants. Some of these 650 tested hybrids proved to have nuts that were classed as Giants being much larger than the filberts produced by male or pollen parent such as the Barcelona, Duchilly or Daviana, and several times the size of the nuts of the female parent which was the wild hazel.
PECANS AND THEIR HYBRIDS
At the same time, October 1924, that I purchased Beaver hickory trees from J. F. Jones, I also procured from him three specimens each of three commercial varieties of pecan trees, the Posey, Indiana and Niblack, as well as some hiccan trees, i.e., hybrids having pecan and hickory parents. Only one tree survived, a Niblack pecan, which, after sixteen years, was only about eighteen inches in height. Its annual growth was very slight and it was killed back during the winter almost the full amount of the year's growth. In the 17th year this tree was dead.
In September 1925, at a convention of the Northern Nut Growers' Association in St. Louis, Missouri, I became acquainted with a man whose experience in the nut-growing industry was wide and who knew a great deal about the types of hickory and pecan trees in Iowa. He was S. W. Snyder of Center Point, Iowa. (He later became president of the Association.) In one of his letters to me the following summer, Mr. Snyder mentioned that there were wild pecan trees growing near Des Moines and Burlington. I decided I wanted to know more about them and at my request, he collected ten pounds of the nuts for me. I found they were the long type of pecan, small, but surprisingly thin-shelled and having a kernel of very high quality.
I first planted these nuts in an open garden in St. Paul, but after a year I moved them to my farm, where I set them out in nursery rows in an open field. The soil there was a poor grade of clay, not really suited to nut trees, but even so, most of the ones still remaining there have made reasonably good growth. I used a commercial fertilizing compound around about half of these seedlings which greatly increased their rate of growth, although they became less hardy than the unfertilized ones. After five years, I transplanted a number of them to better soil, in orchard formation. Although I have only about fifty of the original three hundred seedlings, having lost the others mainly during droughts, these remaining ones have done very well. Some of these trees have been bearing small crops of nuts during the years 1947 to date. The most mature nuts of these were planted and to date I have 17 second generation pure pecan trees to testify as to the ability of the northern pecan to become acclimated.
I gave several of the original seedlings to friends who planted them in their gardens, where rich soil has stimulated them to grow at twice the rate of those on my farm. There were four individual pecan trees growing in or near St. Paul from my first planting, the largest being about 25 feet high with a caliber of five inches a foot above ground. Although this tree did not bear nuts I have used it as a source of scionwood for several years. These graftings, made on bitternut hickory stock, have been so successful that I am continuing their propagation at my nursery, having named this variety the Hope pecan, for Joseph N. Hope, the man who owns the parent tree and who takes such an interest in it.
By the year 1950 the tree had such a straggly appearance, although still healthy and growing but being too shaded by large trees on the boulevard, that Mr. Hope caused it to be cut down. The variety is still growing at my farm, grafted on bitternut stocks and although blossoming it has never produced a nut up to this time.
Another tree given to Joseph Posch of the city of St. Paul, Minnesota, had made even better growth and was luxuriantly healthy and in bloom when it was cut down by the owner because the branches overhung the fence line into a neighbor's yard. This was done in about 1950.
Another tree given to Mrs. Wm. Eldridge of St. Paul still flourishes and is quite large (in 1952 at breast height, 6 inches in diameter) but being in a dense shade, it has not borne any nuts.
The fourth tree, given to John E. Straus, the famous skate maker, presumably exists at his lake residence north of St. Paul. I have not seen it in the last seven or eight years.
Although they are not as hardy as bitternut stocks, I have found the wild Iowa pecan seedlings satisfactory for grafting after five years' growth. I use them as an understock for grafting the Posey, Indiana and Major varieties of northern pecan and find them preferable to northern bitternut stocks with which the pecans are not compatible for long, as a rule, such a union resulting in a stunted tree which is easily winter-killed. Although the Posey continued to live for several years our severe winters finally put an end to all these fine pecans. The root system of the seedling understock continued to live, however.
I chanced to discover an interesting thing in the fall of 1941 which suggests something new in pecan propagation. There were two small pecans growing in the same rows as the large ones planted fifteen years previously. When I noticed them, I thought they were some of this same planting and that they had been injured or frozen back to such an extent that they were mere sprouts again, for this has happened. I decided to move them and asked one of the men on the farm to dig them up. When he had dug the first, I was surprised to find that this was a sprout from the main tap root of a large pecan tree which had been taken out and transplanted. The same was true of the second one, except that in this case we found three tap roots, the two outside ones both having shoots which were showing above the ground. Another remarkable circumstance about this was that these tap roots had been cut off twenty inches below the surface of the ground and the sprouts had to come all that distance to start new trees. All of this suggests the possibility of pecan propagation by root cuttings. These two pecans, at least, show a natural tendency to do this and I have marked them for further experimentation along such lines.
On the advice of the late Harry Weber of Cincinnati, Ohio, an eminent nut culturist, who, after visiting my nursery in 1938, became very anxious to try out some of the Indiana varieties of pecans in our northern climate, I wrote to J. Ford Wilkinson, a noted propagator of nut trees at Rockport, Indiana, suggesting that he make some experimental graftings at my farm. Both Mr. Wilkinson and Mr. Weber gathered scionwood from all the black walnut, pecan, hiccan and hickory trees at their disposal, for this trial. There was enough of it to keep three of us busy for a week grafting it on large trees. Our equipment was carried on a two-wheeled trailer attached to a Diesel-powered tractor, and we were saved the trouble of having to carry personally, scions, packing material, wax pots, knives, pruning shears, tying material, canvas and ladders into the woods. Mr. Wilkinson remarked, on starting out, that in the interests of experimental grafting, he had travelled on foot, on horseback, by mule team and in rowboats, but that this was his first experience with a tractor.
When he saw the type of grafting with which I had been getting good results, Mr. Wilkinson was astounded. He declared that using a side-slot graft in the South resulted in 100% failure, while I had more than 50% success with it. He was willing to discard his type of grafting for mine, which was adequate for the work we were doing, but I wanted to check his grafting performance and urged him to continue with his own (an adaptation of the bark-slot graft to the end of a cut-off stub). We both used paper sacks to shade our grafts. Although results proved that my methods averaged a slightly higher percentage of successful graftings in this latitude and for the type of work we were doing, his would nonetheless be superior in working over trees larger than four inches in diameter and having no lateral branches up to eight feet above ground, at which height it is most convenient to cut off a large hickory preparatory to working on it.
In the late fall of that year, we cut scionwood of the season's growth and inverted large burlap bags stuffed with leaves over the grafts, the bags braced on the inside by laths to prevent their collapsing on the grafts. So we have perpetuated the following varieties:
Hickories: Cedar Rapids, Taylor, Barnes, Fairbanks.
Hiccans: McAlester, Bixby, Des Moines, Rockville, Burlington, Green Bay.
The Major and Posey pure pecans being incompatible on bitternut hickory roots were grafted on pecan stocks, but they proved to be tender to our winters and the varieties were finally lost.
Other experiments I have made with pecans include an attempt to grow Southern pecans from seed, but they seem to be no more hardy than an orange tree would be. It is certain that they are not at all suited to the climate of the 45th parallel. In 1938, I received from Dr. W. C. Deming of Connecticut, some very good nuts from a large pecan tree at Hartford, Connecticut. Of the twelve pecans I planted, only six sprouted, and of these, only one has survived up to this date and is now a small weak tree. Apparently, the seedlings of this Hartford pecan are not as hardy as those from Iowa.
Of the hiccans, hybrids between hickory and pecan, there are several varieties, as I mentioned before. Of these, the McAlester is the most outstanding, its nuts measuring over three inches in circumference and about three inches long. Horticulturists believe that this hybrid is the result of a cross between a shell-bark hickory, which produces the largest nut of any hickory growing in the United States, and a large pecan. I have experimented a number of times with the McAlester and my conclusion is that it is not hardy enough to advocate its being grown in this climate. There are other hiccans hardier than it is, however, such as the Rockville, Burlington, Green Bay and Des Moines, and it is certain that the North is assured of hardy pecans and a few hardy hybrids, which, although they do not bear the choicest pecan nuts, make interesting and beautiful lawn trees. Indeed, as an ornamental tree, the pecan is superior to the native hickory in two definite ways: by its exceedingly long life, which may often reach over 150 years as contrasted with the average hickory span of 100 years, and by its greater size. One pecan tree I saw growing in Easton, Maryland, in 1927, for example, was then seventeen feet in circumference at breast-height, one hundred twenty-five feet in height and having a spread of one hundred fifty feet. The wood of the pecan is similar to that of the hickory in both toughness and specific gravity, although for practical purposes, such as being used for tool handles, the shagbark hickory is enough harder and tougher to make it the superior of the two.
I was pleasantly surprised on October 30, 1953 when a pecan seedling of the Iowa origin, which had not yet borne any nuts, showed a small crop. These nuts were fully matured and were of sufficient size so that they could be considered a valuable new variety of pecan nut for the North. A plate showing a few of these pecans illustrates, by means of a ruler, the actual size of these pecans, and the fact that they matured so well by October 30 indicates that in many seasons they may be relied upon to mature their crop. No other data has been acquired on this variety and we can only be thankful that we can expect it to do a little better in size as successive crops appear, which is the usual way of nut trees. Also, by fertilizing this tree we can expect bigger nuts, as is generally the case. The shell of this pecan is so thin that it can be easily cracked with the teeth, which I have done repeatedly, and although small is thinner-shelled than any standard pecan.
HICKORY THE KING
The acknowledged autocrat of all the native nuts is the hickory. Perhaps not all the experts admit this leadership but it is certainly the opinion held by most people. Of course, when I speak of the hickory nut in this high regard, I refer to the shagbark hickory which, as a wild tree, is native as far north as the 43rd parallel in Minnesota and Wisconsin, and somewhat farther in the eastern states.
Wild hickory nuts have been commercialized only to a slight extent. Its crops are almost entirely consumed in the locality in which they are grown by those people who find great pleasure in spending fine autumn days gathering them. The obvious reason why hickory nuts have not been made a product of commerce lies in the nut itself, which is usually very small and which has a shell so strong and thick that the kernel can be taken out only in small pieces. The toughness of the shell makes cracking difficult, too, and since only rarely is one found that can be broken by a hand cracker, it is necessary to use the flatiron-and-hammer method. It is quite possible, though, that some day the hickory will rival or exceed its near relative, the wild pecan, in commercial favor. The wild pecans which formerly came on the market at Christmastime in mixtures of nuts were just as difficult to extract from their shells as the wild shagbark hickory nuts are now. By means of selection and cultivation, the pecan was changed from a small, hard-to-crack nut to that of a large thin-shelled nut whose kernel was extractable in whole halves. Among many thousands of wild pecan trees were a few which bore exceptionally fine nuts, nuts similar to those now found at every grocery store and called "papershell" pecans. These unusual nuts were propagated by grafting twigs from their parent trees on ordinary wild pecan trees whose own nuts were of less value. These grafted trees were set out in orchards where they produce the millions of pounds of high-grade pecans now on the market.
The question which naturally occurs is, "Why hasn't this been done with hickory nuts?" Hundreds of attempts have been made to do so, by the greatest nut propagators in the United States. They have been successful in grafting outstanding varieties of hickory to wild root stocks but the time involved has prevented any practical or commercial success, since most grafted hickories require a period of growth from ten to twenty years before bearing any nuts. This length of time contrasts very unfavorably with that required by grafted pecans which produce nuts on quite young trees, frequently within three to five years after grafting. This factor of slow growth has set the pecan far ahead of the tasty shagbark hickory. Experimenters have long thought to reduce the time required by the hickory to reach maturity by grafting it to fast-growing hickory roots such as the bitternut or the closely related pecan. Both of these grow rapidly and the bitternut has the additional advantage of growing farther north and of being transplanted more easily. It has always been thought that when a good variety of shagbark hickory had been successfully grafted to bitternut root stocks, orchards of hickory trees would soon appear. This takes me to my discovery of the variety now known as the Weschcke hickory, which I have found fulfills the necessary conditions.