Chapter 8 BUTTERNUT

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Like the hickory tree, the butternut shares in the childhood reminiscences of those who have lived on farms or in the country where butternuts are a treat to look forward to each fall. The nuts, which mature early, have a rich, tender kernel of mild flavor. Only the disadvantage of their heavy, corrugated shells prevents them from holding the highest place in popularity, although a good variety cracks easily into whole half-kernels.

Butternuts grow over an extended range which makes them the most northern of all our native wild nut trees, although their nuts do not mature as far north as hazelnuts do. Butternut trees blossom so early that in northern latitudes the blossoms are frequently killed in late spring frosts. Only when the trees are growing near the summit of a steep hillside will they be likely to escape such frosts and bear crops regularly. I have found that really heavy crops appear in cycles in natural groves of butternut trees. My observation of them over a period of thirty-two years in their natural habitat in west-central Wisconsin has led me to conclude that one may expect butternut trees to bear, on an average, an enormous crop of nuts once in five years, a fairly large crop once in three years, with little or no crop the remaining years.

As a seedling tree of two or three years, the butternut is indistinguishable from the black walnut except to a very discerning and practiced eye, especially in the autumn after its leaves have fallen. As the trees grow older, the difference in their bark becomes more apparent, that of the butternut remaining smooth for many years, as contrasted to the bark on black walnut trees which begins to roughen on the main trunk early in its life. Bark on a butternut may still be smooth when the tree is ten years old. Forest seedlings of butternut, when one or two years old, are easily transplanted if the soil is congenial to their growth. Although the tree will do well on many types of soil, it prefers one having a limestone base, just as the English walnut does.

A butternut seedling usually requires several more years of growth than a black walnut does before it comes into bearing, although this varies with climate and soil. It is impossible to be exact, but I think I may safely say that it requires at least ten years of growing before a seedling butternut tree will bear any nuts. Of course, exceptions will occasionally occur.

As a butternut tree matures, it spreads out much like an apple or chestnut tree. Of course, it must have enough room to do so, an important factor in raising any nut tree. Enough room and sunlight hasten bearing-age and insure larger crops of finer nuts. Grafting valuable varieties of butternut on black walnut stock will also hasten bearing. I have had such grafts produce nuts the same year the grafting was done and these trees continued to grow rapidly and produce annually. However, they were not easy to graft, the stubborn reluctance of the butternut top to accept transplantation to a foreign stock being well known. This factor will probably always cause grafted butternut trees to be higher in price than black walnut or hickory. The reverse graft, i.e., black walnut on butternut should never be practiced for although successful, the black walnut overgrows the stock and results in an unproductive tree. Specimens 25 or more years old prove this to be a fact.

Butternut trees are good feeders. They respond well to cultivation and lend themselves to being grafted upon, although, from my own experience, I question their usefulness as a root stock. I have found that when I grafted black walnuts, English walnuts or heartnuts on butternut stock, the top or grafted part of the tree became barren except for an occasional handful of nuts, even on very large trees. Since this has occurred throughout the many years of my nut culture work, I think it should be given serious consideration before butternut is used as a root stock for other species of nut trees.

Weschcke Butternut. Smooth shallow convolutions of shell allow kernels to drop out freely. Drawing by Wm. Kuehn. I had the good luck to discover an easy-cracking variety of butternut in River Falls, Wisconsin, in 1934, which I have propagated commercially and which carries my name. A medium-sized nut, it has the requisite properties for giving it a varietal name, for it cracks mostly along the sutural lines and its internal structure is so shallow that the kernel will fall out if a half-shell is turned upside down. I received one of those surprises which sometimes occur when a tree is asexually propagated when I grafted scions from this butternut on black walnut stock. The resulting nuts were larger than those on the parent tree and their hulls peeled off with almost no effort. Whether these features continue after the trees become older is something I shall observe with interest.

Self hulling Butternut. Weschcke variety. Drawing by Wm. Kuehn.

The nearly self-hulling quality of these nuts makes them very clean to handle. The absence of hulls in cracking butternuts not only does away with the messiness usually involved, but also it allows more accurate cracking and more sanitary handling of the kernels. In 1949 I noticed a new type of butternut growing near the farm residence. This butternut was fully twice as large as the Weschcke and had eight prominent ridges. The nut proved to be even better than the older variety and we intend to test it further by grafting it on butternuts and black walnut stocks. Although hand-operated nutcrackers have been devised to crack these and other wild nuts, they are not as fast as a hammer. If one protects the hand by wearing a glove and stands the butternut on a solid iron base, hitting the pointed end with a hammer, it is quite possible to accumulate a pint of clean nut meats in half an hour.

The butternut tree is one whose lumber may be put to many uses. It is light but very tough and stringy and when planed and sanded, it absorbs varnish and finishes very well. Although not as dark in natural color as black walnut, butternut resembles it in grain. When butternut has been stained to represent black walnut, it is only by their weight that they can be distinguished. In late years, natural butternut has become popular as an interior finish and for furniture, being sold as "blonde walnut," "French walnut," or "white walnut," in my opinion very improper names. I see no reason for calling it by other than its own. Depletion of forests of butternut trees brings its lumber value up in price nearly to that of fine maple or birch, approaching that of black walnut in some places.

I have run several thousand feet of butternut lumber from my farmland through my own sawmill and used it for a variety of purposes. It is probably the strongest wood for its weight except spruce. I have used it successfully to make propellers which operate electric generators for deriving power from the wind. Because butternut is so light and, properly varnished, resists weathering and decay to so great an extent, I have found it the best material I have ever tried for such construction. In building a small electric car for traveling around the orchards, I used butternut rather than oak or metal, which saved at least 100 pounds of weight, an important matter since the source of the car's power is automobile storage batteries.

Butternut is very durable in contact with the ground and is used for fence posts on farms where it is plentiful. Bird houses built of this wood will last indefinitely, even a lifetime if they are protected with paint or varnish. Butternut is like red cedar in this respect, although much stronger. Stories have been told of black walnut logs which, after lying unused for fifty years, have been sawed into lumber and found to be still in excellent condition. It is quite likely that the same could be said of butternut for these woods are very much alike in the degree of their durability and resistance to weather.

An incidental value butternut trees have is their ability to bleed freely in the spring if the outer bark is cut. Therefore, they can be tapped like maple trees and their sap boiled down to make a sweet syrup. It does not have the sugar content that the Stabler black walnut has, however. Another possible use is suggested by the shells of butternuts which, even when buried in the ground, show great resistance to decay. I have found them to be still intact and possessing some strength after being covered by earth for fifteen years. This indicates that they might be used with a binder in a composition material. Their extreme hardness also offers a good wearing surface.

Electrically operated wagon constructed of native butternut wood known for strength and light weight as well as durability. Author's sons aboard. Photo by C. Weschcke 1941.

Not only good things can be said of the butternut tree and it would be wrong to avoid mentioning the deleterious effect that a butternut tree may have on other trees planted within the radius of its root system. I have had several experiences of this kind. One butternut tree on my farm, having a trunk six inches in diameter, killed every Mugho pine within the radius of its root system. This amounted to between 50 and 100 pines. Their death could not be attributed to the shade cast by the butternut as Mugho pines are very tolerant of shade. As the first branches of the butternut were more than three feet off the ground, the pines could not have been influenced by the top system of the tree nor do I believe that it was due to fallen leaves, but rather directly to the greatly ramified roots. Large evergreens, such as Colorado blue spruce, native white pine, limber pine and Jeffrey pine are known to have been similarly influenced. While small butternut trees do not, in my experience, have this effect, this may be explained by the fact that the radius of their root systems is much more limited. Most plants, other than pines, thrive within the influence of butternut roots, however, and it certainly does not damage pasture grass as some of the country's best grazing land is among such trees. The damage results from a chemical known as Juglone which is elaborated by the root system and when the roots of the butternut cross those of its evergreen neighbor, this acts as a poison to the evergreen and may kill it.

An 8-foot propeller of butternut wood is the prime mover for wind power generator which in a brisk wind generated 110 volts and 10 amperes at 300 RPM.

The butternut is attacked by one serious disease which is in the nature of a blight (melanconium oblongum), since it is transmitted through spores. It usually attacks old trees, the branches of the top part dying, and the bark on the main trunk becoming loose. The disease progresses slowly and I have seen large trees infected for twelve or fifteen years, continuing to bear fine crops. It does have a very weakening effect, though, and eventually saps the life from the tree long before its natural span of life of about fifty years is over.


                                                                                                                                                                                                                                                                                                           

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