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 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 circ.u.mstances.
[Ill.u.s.tration: _Stabler variety of Black Walnut grafted on a Minnesota seedling stock bore many years but was winter killed. Photo by C.
Weschcke_]
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.
[Ill.u.s.tration: _Stabler graft on old seedling grafted in May, 1938 bearing in August of the same year. Photo by C. Weschcke_]
[Ill.u.s.tration: _Cut Leaf Black Walnut. Scions furnished by Harry Weber of Cincinnati, Ohio. Variety was hardy on Minnesota seedling for about 5 years. Photo by C. Weschcke_]
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"
a.s.sociation. Neither the Laceleaf nor Deming Purple are hardy for this climate but survived several years nevertheless before succ.u.mbing to one of our periodical test winters.
Chapter 4
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 s.e.xes 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"
a.s.sociation, 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 a.s.set 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 sh.e.l.l 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 sh.e.l.l 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.
[Ill.u.s.tration: _3/4 Natural size Filberts_]
[Ill.u.s.tration: _3/4 Natural size Hazilberts and Winkler Hazel_]
[Ill.u.s.tration: _31/32 of actual size Hazilberts. Left to right: No. 3, No. 5, No. 4, No. 2_]
[Ill.u.s.tration: _No. 1 Hazilbert about 9/15/42. Note almost identical size and shape of this actual photograph of No. 1 compared to predetermined size and shape in drawing made almost one year previous to photograph. Plant had not produced any nuts prior to crop of 1942_]
Chapter 5
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 sh.e.l.l rather than to its lacking flavor. Its flavor, which seldom varies much regardless of size, shape or thickness of sh.e.l.l, 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 a.s.sociation, 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.