Chapter VIII: The Walnut (1)

Juglans. The ancient Latin name, first used by Pliny, contracted from _Jovis glans_, the nut of Jove or Jupiter. A genus of about eight species, three or four of these indigenous to the United States.

=Order=, _Juglandaceae_ (Walnut family).--Medium to large deciduous trees with odd-pinnate leaves; leaflets from fifteen to twenty-one, serrate, mainly oblong and pointed. The sexes of flowers separate (monoecious) on the same tree, the males in pendulous green cylindrical catkins two to three inches long, solitary or in pairs, sessile,--not stalked, as in the hickories,--issuing from the one-year-old twigs, and at the upper edge of the scar left by the falling leaf of the previous season (Fig. 73), showing that the male organs emanate from an aggregation of bud-cells in the axils of the leaves during the preceding summer and autumn. Female flowers terminal on the new growth in spring, also single, in clusters, and occasionally in long pendulous racemes with a four-cleft calyx, four minute petals and two thick curved stigmas. Fruit round or oblong (Fig. 74); husk thin, drying up without opening by seams, as in the hickories. Shell of nut either rough and deeply corrugated, with sharp-pointed ridges, or quite smooth, with an undulating, wavy surface, very thick in some species and thin in others; kernel two- or indistinctly four-lobed, united at the apex, fleshy, rich and oily.

=History.=--The common walnut, so long and widely known in commerce under various names, such as Persian, English, French, Italian and European walnuts, also as Madeira nut, and recently Chile walnut, are now all believed to have descended from trees native of Persia, most plentiful in the province of Ghilan on the Caspian sea, between latitude 35 deg. and 40 deg., hence the old Grecian name of the fruit, viz.: Persicon and Basilicon, or Persian Royal nut, probably because either introduced by the Greek monarchs, or sent to them by the Persian kings. Later,--according to Pliny,--the Greeks called the trees _Caryon_, on account of the strong scent of the foliage, and from this name Nuttall coined his word, _Carya_, for our indigenous hickories, as explained in the preceding chapter. It should also be noted here that the elder Michaux, in 1782-4, was the first modern botanist to visit the province of Ghilan, and he determined, by personal investigation, that this species of the walnut was really indigenous to that region of country, along with the peach and apricot.

Earlier European authors claim that the walnut was first introduced into Italy by Vitellius (emperor) early in the first century of the Christian Era,--but this is uncertain,--the Romans giving it the name of _Juglandes_, or the nut of Jove or Jupiter, both being the same mythical personage. The nuts, at this early day, were highly prized, and also the wood of the tree, the latter being even more valuable than that of the citron (orange and lemon). Ovid wrote a poem about these nuts, entitled _De Nuce_, from which we learn that boys were employed to, or did of their own accord, knock off these nuts; and that at marriages walnuts were thrown by the bride and bridegroom among the children, a ceremony which was supposed to indicate that the bridegroom had left off his boyish amusements, and that the bride was no longer a votary of Diana, and it is quite probable that the French word for nuptials, _des noces_, was derived from this ancient custom. The ancients also believed that walnuts possessed powerful medicinal properties, even to the curing of hydrophobia; but in these latter days they have lost most of their curative virtues, in the opinion of the medical fraternity.

As with the chestnut, the planting of the walnut extended northward into Gaul (France), hence the earlier name of Gaul nuts, which became corrupted into walnuts by the English-speaking people. The Italian name is _Noci_; in France, _Noyer_; and the Germans, with their usual habit of compounding names, call it _walnuss-baum_ or walnut tree.

Joannis De Loureiro, in his work on the plants of China, "Flora Cochinchinensis," published in 1790, claims that this Persian walnut is also a native of the northern provinces of China, with two other species which he describes (p. 573), adding, however, that one of these is cultivated in Cochin China, and the other is found wild in the mountains.

The wild form of this world-wide-famous nut is, doubtless, quite different from the varieties with which we are familiar, for two thousand years or more of continuous cultivation and selections have greatly changed the character of these nuts, as well as the habit of the trees. The nuts from the wild trees are said to have a rather thick shell, and to be much smaller than the best of the improved cultivated varieties, or very like those we now obtain in China and Japan. The Persian walnut, in its many varieties, has been planted almost everywhere in Europe as far north as Warsaw, but does not appear to have run wild and become naturalized, as with many other kinds of fruit and forest trees. In Great Britain it has probably been cultivated ever since the invasion of the country by the Romans, although a much later date is named by some of our modern horticultural authorities. Dodoens (1552), Gerarde (1597), Parkinson (1629), and other of our early authors of works on cultivated plants, speak of the Persian walnut as common in various countries of Europe, Great Britain included. John Evelyn, in his "Sylva" (1664), says:

"In Burgundy, walnut trees abound where they stand, in the
meadows of goodly lands, at sixty and a hundred feet distance,
and so far as hurting the crop, they are looked upon as great
preservers, keeping the ground warm, nor do the roots hinder the
plow."

Evelyn, no doubt, had read what Pliny had said on this point, viz.:

"Even the oak will not thrive near the walnut tree; which, if it
be true, may be owing to the interference of their roots in the
subsoil; but it is certain that neither grass nor field nor
garden crops thrive well under the walnut."

Evelyn was far too good a gardener and close observer to fall into the error of attributing noxious properties to the walnut tree, although Pliny's assertion, which has no foundation beyond his imagination, has been many times repeated in these days of supposed general intelligence. Small plants may fail, under the shade of large trees, or when deprived of moisture by the roots of such trees, but the walnut is no exception to the rule; in fact, such deep-rooted kinds are less injurious than those with roots nearer the surface. Evelyn, in continuing his account of the walnut in Germany, says:

"Whenever they fell a tree, which is only the old, decayed, they
always plant a young one near him, and, in several places
betwixt Hanau and Frankfort, no young farmer whatsoever is
permitted to marry a wife till he bring proof that he is a
father of such a stated number of walnut trees; and the law is
inviolably observed to this day, for the extraordinary benefit
which this tree affords the inhabitants."

What a pity that some such custom could not have prevailed during the past century in the United States. The author from whom I have just quoted adds that the Bergstrasse, which extends from Heidelberg to Darmstadt, is all planted with walnuts.

Cold winters, however, have occasionally played havoc with the walnut trees in Europe, and one of these occurred in 1709, when the greater part of the trees were seriously injured, especially in Switzerland, Germany and France. Many trees were cut down for their timber, which is always in great demand for gun-stocks and furniture. Certain Dutch capitalists, foreseeing the scarcity of walnut timber, bought up all they could procure, and years afterwards sold it at a greatly advanced price. In the year 1720 an act was passed in France to prevent the exportation of walnut timber, and this led to the planting of these trees more extensively than at any previous date; this practice has continued to the present time, hence the immense revenue secured from the exportation of these nuts. The people of the United States are good customers for the surplus stock of Europe, and will probably so continue, until we wake up to a sense of our folly of perpetually buying articles that could be readily produced at home, and at a very large profit.

=Persian Walnut in America.=--The date of the first experiment in planting this nut in this country is now probably unknown, but the oldest tree that I have been able to find with anything like a satisfactory history, is still growing vigorously at Washington Heights, on Manhattan Island, near 160th street and St. Nicholas avenue. I gave a brief history of this noble monarch of its race in the _American Garden_ for September, 1888, from which the following account is condensed:

"In 1758 Roger Morris, an English gentleman, built a spacious
mansion on his estate, at what, in later years, became known as
Washington Heights. His grounds were well laid out for that
time, and many rare foreign trees and shrubs planted, among them
several, as then called, English walnuts. Whether these trees
were raised from the nuts, or plants of some size imported, is
not now known. Mr. Morris may have procured the seedlings from
the Prince Nursery, Flushing, L. I., for this famous garden was
established in 1713, or forty-five years previous to the
building of the Morris mansion and the planting of the grounds
about it.

"At that period no one doubted the hardiness of the so-called
English walnut in America, and as most of the nuts and trees
procured for planting came from acclimated stock in Great
Britain or the cooler region of Europe, success usually attended
such experiments. Our pioneers and horticulturists fully
expected that the trees would thrive and bear nuts in abundance,
and time has shown that they were not mistaken, although we
frequently see it stated at this late day, that the Persian
walnut is not hardy north of the latitude of Washington,
Philadelphia, or other cities south of New York.

"One hundred and thirty-eight years have rolled by since walnut
trees were planted at Washington Heights, and at least one of
the originals has escaped destruction and holds its head aloft,
defying the tempests which frequently sweep over that elevated
and exposed spot on Manhattan Island. This veritable patriarch
of its race in America is a monster in size, its stem between
four and five feet in diameter at the base and more than
seventy-five feet high, with wide-spreading branches.

"In the summer of 1776 the Battle of Long Island was fought, and
the American forces were compelled to retreat in confusion to
New York, thence northward up the island; but when they reached
Fort Washington, not far from the eleventh milestone on the old
Albany post road, they made a stand and proceeded to entrench
themselves at that place. This was in September, 1776, and
General Washington took possession of the Morris mansion near
by, making it his headquarters, and, as this was at the season
when the walnuts had reached an edible stage, we may safely
presume, from his well-known predilection for such delicacies,
that he tested the quality of the Morris walnuts. One hundred
and twenty years later I am writing this, with some fresh
specimens of nuts before me from that same old tree.

"This old patriarch has cast its shade over many a noted person
in its time, for in 1810 the Morris estate passed into the hands
of Madame Jumel, a lady long famous for her hospitality and the
good cheer she extended to the surviving patriots of the
Revolution. From 1810 to the time of her death, 1865, Madame
Jumel's household always had an abundance of walnuts from the
old tree, and one of the workmen on the place informed me that
about two cartloads was considered a fair annual crop."

It cannot be many years before this old tree will meet the same fate that has overtaken many of its younger contemporaries which were once growing in the neighborhood, for with the rush for building lots and the opening of new streets and avenues, trees are usually in the way, and in such cases even patriarchs are not sacred, nor do they command much respect from our urban population.[2]

[Footnote 2: Since writing the above, and while these pages are being put in type, accidentally I learn with regret that the old Morris walnut tree has been destroyed.]

A half-century ago there was quite a large number of walnut trees scattered about on the northern half of Manhattan Island, many of these probably descendants of the old Morris trees, but of this nothing definite is now known. A number of persons whose ages permitted them to scan the early days of the present century, have assured me that in their childhood they had often collected walnuts from goodly sized trees on farms, from Harlem northward on the island. The largest number of Persian walnut trees planted in any one place was on the Tieman farm at Manhattanville, these being set out as roadside trees, some of which are still standing, although in the march of improvements they must soon disappear. These trees have always been noted for their productiveness, bearing a full crop every alternate year, and a lighter one in what is termed the "off season."

While the old Morris walnut tree, and the large number growing on the Tieman estate, and scores of others scattered about New York city and its suburbs, have been, and many still are, living witnesses of the fact that varieties of the Persian walnut will thrive in this latitude, certain horticultural authors and essayists have continually asserted the contrary.

Mr. F. J. Scott, in his superb and voluminous work, "Suburban Home Grounds," in speaking of this species of the walnut, says, p. 351:

"Though greatly valued in England and on the continent for its
beauty, as well as for its nuts, its want of hardiness in the
Northern States, and lack of any peculiar beauty in the South,
has prevented its culture to any great extent in this country.
South of Philadelphia it may be grown with safety."

This seems strange language to have come from such an eminent authority as the late Mr. Scott, inasmuch as he must have passed a hundred times within sight, if not in the very shadow of the rows of old walnut trees growing at Manhattanville, when going from New York city to Newburgh, where he studied landscape gardening under the lamented A. J. Downing, and to whom the work from which I have quoted is dedicated. It is quite evident, however, that our author, like many others, failed to see things that should have interested him.

As an offset to Mr. Scott's idea of the northern limit for the successful cultivation of this nut, I may refer to the work of Mr. George Jacques, "Practical Treatise on Fruit Trees, Adapted to the Interior of New England," published at Worcester, Mass., 1849. In referring to the European walnut, p. 238, he says:

"It is perfectly hardy on Long Island, and to the south of New
York, and as far north as the city of Charlestown in this State
(Mass.), where there may be seen, in the enclosure of a
residence on Harvard street, two fine trees of this kind, either
of them much taller and larger than our large-sized apple trees.
We have eaten nuts from these trees well ripened and fully equal
to any of those imported. The trees often bear a crop of some
bushels."

It is unnecessary to search for further proof to show that certain excellent varieties of the Persian walnut do thrive and bear abundantly in our Northern States; not, perhaps, in the extreme boreal borders of New England, nor in those of the northwest, but the acclimated sorts are pretty safe as far north as 42 deg. of latitude, and in protected locations may crowd up a half degree more. I have found very productive trees of this nut in northern New Jersey, several in Bergen county, others in Passaic, and thence southward, and while they are few in number, they are sufficient to prove that this tree is adapted to the soil and climate of the entire State. We seldom find more than one or two trees in any garden, and these are probably more the result of accident than design, their owners seeming to be satisfied in possessing something in the way of a tree not common in the neighborhood, never thinking that it might be well to plant enough of such trees to have them become a source of revenue. The parentage of quite a number of these bearing trees is readily traced to the Morris and Tieman stock, showing that these old trees are of a hardy and prolific race, which are well worthy of perpetuation for cold climates. Very old and large walnut trees are reported as growing in Pennsylvania and other of the Middle States, but they are far from being numerous. It has long been claimed that this species of nut succeeded best in the Southern States, and it is probably true, especially with the tender varieties; but for some reason, unknown to me, they have not been planted there in sufficient numbers to have, as yet, become of any commercial importance.

During the past twenty-five years these nuts have been more extensively planted in California than elsewhere in the United States, and we may expect soon to know something definite in regard to results. Nearly all of the favorite French varieties have been introduced, and are now being tested in different parts of the State, and it is quite likely that the greater part will succeed, although some of the early-blooming sorts may fail in localities subject to late spring frosts. Previous to the introduction of grafted trees of the named varieties, the only trees of this kind planted in California were seedlings raised from the common imported nuts; but I have no statistics at hand to determine the date of the first plantings of this kind.

Of late years there has been received, at some of our seaports, and especially at New York, some quite large consignments of walnuts from South America, under the name of "Chile walnuts," but they are only varieties of the Persian raised in Chile. They are generally of good size, moderately thin shelled, with plump kernels of excellent flavor. They are in great demand for confectionery, and are really better for such purposes than the larger and fancy bleached walnuts imported under the somewhat general name of Grenobles, or French walnuts. Owing to the difference of climate, these Chile walnuts arrive here late in winter, or about the time those coming from European countries the previous autumn begin to become somewhat stale.

Of our native species of this genus (_Juglans_), the almost everywhere common butternut ranks first in flavor and general estimation, but owing to its hard, rough shell, and the difficulty in extracting the kernel, it has never become of any considerable importance, although usually found in our markets in limited quantities. Of course, it is a general favorite in the country, and wherever found in sufficient quantities the boys and girls lay up a goodly supply for winter use; and cracking butternuts during the long winter evenings is a pastime and pleasure not to be ignored nor forgotten. The flavor of the butternut is far more delicate, and better, than any of the Persian species, but the difficulty in extracting the rather small kernel is a serious objection.

The black walnut has a larger kernel, in proportion to its size, than the butternut, and it is not so difficult to extract when the nuts are dry, but the flavor is too rank for most palates, although it has often been referred to as excellent by the earlier botanists who visited this country; but it has never been considered of much value until quite recently, or since the manufacturers of confectionery discovered that heat somewhat subdued the rank flavor, and now many tons of the meats are annually consumed in candies and walnut cakes. I am credibly informed that cracking black walnuts and shipping the meats to our larger cities has become quite an extensive industry in several of the Middle and Western States. We have two other but smaller native species of the walnut that will be described further on, under the head Species and Varieties.

=Propagation of Walnuts.=--The propagation of the walnut in the natural way, or by seed, is exceedingly simple, for the nuts grow readily and freely if planted soon after they are ripe, or any time before they become old and the kernels shriveled. It is, of course, best to plant them while fresh, but they are not at all delicate, and may be transported a long distance in a dry condition without seriously affecting their vitality. If walnuts are given the same care as recommended in the preceding pages for other kinds of nuts, so much the better.

The seedlings of walnuts, like those of other species, usually produce long taproots, and if grown in a compact soil, these will have few small lateral fibers the first season, as shown in Fig. 75; but when taken up and the vertical main root shortened at _a_, and then replanted, they produce fibrous roots in abundance. The trees of almost any age from one to twenty years old, are not at all difficult to make live when transplanted, provided the branches or tops of the trees are reduced, to correspond with loss of roots in digging up at the time of removal. It may be well to give a word of caution to the novice in nut culture about pruning nut trees in spring, after the sap begins to flow; for if done at this time they will bleed freely and leave unhealthy wounds and black, unsightly spots on the bark. Prune walnuts in summer or early in winter, to give time for the wounds to season before the buds swell in spring. If young trees are to be dug up, prune after they are taken from the ground, then the sap will not flow from the wounds. This is true of all deciduous trees, vines and shrubs. If the trees have few small roots when taken up, prune severely; but if roots are abundant, little pruning will be required. It is seldom, however, in transplanting walnuts, that the pruning need be as severe as recommended for the chestnut; in fact, having transplanted walnuts of various species, and of all ages from one to twenty years, without the loss of a plant, I have come to the conclusion that they are pretty safe trees to handle, in this climate, at least, if not elsewhere.

In seeking walnuts from a distance, for planting anywhere in the Middle or Northern States, it will be well to learn something in advance about the climate in which the nuts are raised; for it would be folly to send for either trees or nuts to a warm or semi-tropical region, like that of southern France or Spain, for a stock to cultivate in a climate as cold as that of New York, New Jersey, and States on the same line westward. We might, perchance, from such importation, secure one hardy plant in a hundred or thousand, but there would be no certainty of even this small number.

This idea of acclimation and adaptation of trees to conditions and climate should not be overlooked by the nut culturist, no matter from what source he procures his stock, whether from abroad, or some distant region of his own country. If it can be obtained from a region where it has been growing under conditions similar to those to which it is to be transferred for cultivation, then the chances of success will certainly be largely augmented. Acclimation is a slow process; in fact, too slow for us to expect to secure any appreciable advantages from it in a lifetime, but in nature we seek final results, leaving time out of the question.

In raising seedling trees we cannot expect much more than a reproduction of the species, and not that of the parent tree. Plants that have been subjected to unnatural conditions and surroundings, as usual under cultivation, are far more likely to show a wider range of variation in the seedlings than those growing wild in their native habitats; but even the latter cannot be depended upon to reproduce exact types from seed. In other words, there is nothing certain about seedling nut trees; the large nuts may produce trees bearing very small ones, the early-ripening give late ones, the tall dwarf trees and the precocious fruiting some of the most tardy varieties; and yet, with all this uncertainty, we still think it best to select for planting the best nuts obtainable, _i. e._, best and most promising for the conditions under which the seedlings are to be grown.

For the multiplication and perpetuation of choice varieties we must resort to artificial modes of propagation, mainly by budding and grafting. These modes, however, while the best at present known, are so difficult and uncertain in cool climates,--even in the hands of the most skilful propagators,--that grafted walnut trees have never been very plentiful in the nurseries of this or other countries with which we have commercial relations. In the south of France nurserymen appear to have been more successful in the propagation of walnuts by budding and grafting, than elsewhere; but in the northern provinces, as well as in Great Britain, we hear little of this mode of propagation. So difficult has this mode of propagating the walnut been considered in England, that Thomas Andrew Knight, president of the London Horticultural Society, early in the present century discouraged all attempts to propagate this tree by such means; but later, in a paper read before the Society April 7, 1818, he admits to having changed his mind, especially in regard to budding the walnut, and says:

"The buds of trees of almost every species succeed with most
certainty when inserted on the shoots of the same year's growth;
but the walnut tree appears to afford an exception; possibly, in
some measure, because its buds contain within themselves, in the
spring, all the leaves which the tree bears in the following
summer, whence its annual shoots cease to elongate soon after
its buds unfold; all its buds of each season are also,
consequently, very nearly of the same age, and long before any
have acquired the proper degree of maturity for being removed,
the annual branches have ceased to grow longer or to produce new
foliage.... To obviate the disadvantage arising from the
preceding circumstances, I adopted means of retarding the period
of the vegetation of the stocks comparatively with that of the
bearing tree: and by these means I became partially successful.
There are, at the base of the annual shoots of the walnut and
other trees, where these join the year-old wood, many minute
buds which are almost concealed in the bark, and which rarely or
never vegetate but in the event of the destruction of the large
prominent buds which occupy the middle and opposite end of the
annual wood. By inserting in each stock one of these minute buds
and one of the large prominent kind, I had the pleasure to find
that the minute buds took freely, while the large all failed
without a single exception."

From the above and other remarks of Mr. Knight, in the paper read by him, I infer that he kept the stocks in pots stored in a cool place in spring, until he could obtain shoots of the season from bearing trees, and from these minute undeveloped axillary buds for inserting in the stocks. These buds, as he informs us, are inserted in the wood of the preceding season, and near the summit or top. He does not give any directions for holding the buds in place, whether by waxed or plain bass ligatures; the former, however, would probably be preferable, for the purpose of excluding the air and water.

Some twenty years later (1838) J. C. Loudon, in "Arboretum Britannicum," etc., refers to the propagation of the walnut as follows:

"Much has been written on the subject by French authors, from
which it appears that in the north of France, and in cold
countries generally, the walnut does not bud or graft easily by
any mode; but that in the south of France and north of Italy it
may be budded or grafted by different modes, with success. At
Metz, the Baron de Tschoudy found the flute method (Fig. 76)
almost the only one which he could practice with success. By
this mode an entire ring of bark, containing one or more buds,
is removed from a twig on a tree to be multiplied, and
transferred to the stock, and made to fit as shown. If the ring
is too large, a slice may be cut off; and if too small, a piece
of the bark of the stock may be left to fill the space."

Both stock and parent tree must be in about the same condition or stage of growth when this ring budding is done, in order that the bark containing the bud may peel off freely from the wood, and this is always in the spring, soon after the buds begin to unfold and the sap is in motion. Loudon says that in Dauphine, France, young plants in the nurseries are budded chiefly by this mode, which succeeds best the closer the operation is performed to the collar of the plant; and the same is true in grafting, the nearer the root the better, as has been found by experience with hickories.

Charles Baltet, in his "L'Art de Greffer," recommends grafting in the usual mode of crown grafting, also flute or ring grafting, in April or May, and ordinary cleft grafting close to the root and at the forks of the branches, etc. He says that the cion should be cut, as much as possible, obliquely across the pith, so that it may be exposed on one side only. He also advises using cions whose base consists of wood of two years' growth, and these furnished with a terminal bud. He cautions propagators against grafting early-growing kinds upon those of later vegetation. If walnuts of any of the native or foreign species have been successfully propagated by budding or grafting, at any of the nurseries in our Eastern States, it has not been made known in the nurserymen's catalogues.

Michael Floy, who early in the present century had quite extensive grounds devoted to fruit and ornamental trees, near what is now the center of New York city, as we learn from his "Guide to the Orchard," published in 1833, claims, in this work, that the Persian walnuts thrive well in this country, but admits that he had never succeeded in grafting the trees, and with the hickories had no better success, although he had tried them many times; but he adds:

"Still I do not say it is impossible either to bud or graft
them; but there is something peculiar about it, for both the bud
and graft turn black when cut, almost instantaneously. Others
may succeed better, but let them try it before they affirm it
upon hearsay; they may succeed very well by inarching."

Coming down to the present day, in our search for facts and information in regard to the propagation of varieties of the walnut, we may find it interesting to visit California, which, of all the States of the Union, is perhaps the best adapted to nut culture in general; besides, a larger number of nut trees of various kinds have been planted there than elsewhere in this country. It is in California that we find such men as Felix Gillet, of Nevada City, an enthusiastic propagator and cultivator of fruit and nut trees, and especially of the latter, if we may judge by his works and writings on this branch of horticulture,--and so far as I have been able to learn, he is the only nurseryman in the United States who has grafted walnut trees of many different varieties for sale.

In regard to modes of propagation, Mr. Gillet says that the common mode of shield budding, as employed on fruit trees, fails entirely with small walnuts from one to three years from the seed, and it does but seldom succeed even on larger stocks. When tried on large, old stocks, he advises removing all the wood from the inner side of the strip of bark on which the bud is situated, and at the same time have this strip not less than two inches long and as broad as possible. He describes his mode of grafting walnuts, which does not differ materially from those already given. That he has never attained any very remarkable results may be inferred from the following:

"We will add that the 'grafted walnuts' that we offer were
grafted expressly for us, regardless of cost, by the most
reliable firm to be found in the walnut district in France,
through a process discovered several years ago, and which we
will briefly describe for the benefit of people who may be
inclined to try this new method of grafting very young walnuts.

"One-year-old seedlings of the size of the little finger, or
about one-half inch in diameter at the butt, are selected, the
root cut back short enough to permit the planting of the trees
in pots of three inches in depth; the trees, previously to being
potted, are grafted with cions exactly of the same size, whip or
cleft grafting being used; the pots are then taken to a hot or
propagating house, and a glass bell set over them to prevent the
outside air getting to the grafts, the temperature of the house
being kept day and night, at least for fifteen days, or till the
grafting has taken, to 70 deg. F. When the grafts are well taken and
growing, the glass bells are removed, and the grafts allowed to
grow three or four inches, before the little grafted trees are
set out in nursery rows; it may be preferable, especially in
certain parts of the country, to keep the trees in the pots till
the ensuing spring. Forty to fifty per cent of the grafts will
succeed, and it is the best that can be done.

"This mode of grafting the walnut, besides requiring a hothouse,
needs the care of a skillful person to make it succeed. So are
grafted the little trees that we import from France, and that we
plant in nursery rows and offer to the public."

For other modes of root grafting, I refer the reader to those recommended for the hickories, in the preceding chapter. Propagating walnuts by layers is practicable, where the small trees have been cut down to force out new shoots near the surface of the ground, then bent down and covered with soil in the usual method of layering woody plants.

=Planting and Pruning.=--The plants will produce a greater number of fibrous roots if the nuts are planted in light, loose, but rich soil, than in a heavy, tenacious one; but with all kinds it is best to transplant when one or two years old, and cut off a portion of the taproots, as recommended for the hickories. When removed from the nursery rows for final planting, prune away nearly or quite all side branches, leaving only the terminal bud if the trees are not more than six to eight feet high. After final planting where the trees are to remain permanently, very little pruning will ever be required, further than to cut away branches that may cross each other, or to shorten some to give proper form to the head. No tree in cultivation requires less pruning than walnuts.

As a genus of trees the walnuts flourish best in deep, rich loam, rather light than heavy, and in this country require considerable moisture at the roots, and some, like the butternut, succeed best in bottomlands, near creeks and larger streams. If the soil is naturally too dry for such trees, the fault can be readily remedied by the use of some form of mulch applied to the surface of the soil around the stem after planting, renewing this annually, or oftener if necessary, until the trees are large enough to shade the ground.

Walnut trees, as well as the closely allied hickories, are well adapted for roadside planting, and when set in such positions are far less likely to be injured by insects than when planted in orchards or large groups, besides serving a double purpose, being ornamental as well as useful. They may also be planted around buildings, and where other and less valuable trees are generally grown. There are also millions of acres of rocky hill-sides and old fields which might be utilized for nut orchards, and if rather widely scattered over such land they would prove beneficial in shading the pasture grasses. First of all, however, let us have rows of these trees along all our country roads, after which it will be time enough to begin planting them elsewhere.

SPECIES AND VARIETIES OF WALNUTS.

=Native of the United States= (_Juglans cinerea._ Linn.). Butternut. White Walnut.--Leaflets fifteen to nineteen, oblong-lanceolate and sharp-pointed, rounded at the base, downy, especially on the underside, petioles covered with viscid hairs; fruit oblong, two or more inches in length, with a clammy husk, not opening when ripe, but closely adhering to the deeply corrugated and rough, thick shell. Trees with wide-spreading branches, and of medium hight, or from forty to fifty feet, but in deep forests sometimes sixty to seventy, with stems two to three feet in diameter. A common tree in moist soils almost everywhere, from the Canadas southward to the highlands of northern Georgia, Alabama, and sparingly in Mississippi and Arkansas, and all the States bordering the Mississippi river northward to Minnesota. A valuable timber tree, with soft, light wood, much used of late for furniture and inside house finishing. In early times the inner bark was employed for making a yellow dye, also as a medicine, the extract being a mild cathartic, hence one of the specific names, _Cathartica_.

Synonyms.

_Juglans oblonga alba_, Marshall.
_Juglans cathartica_, Michaux.
_Carya cathartica_, Barton, 1818.
_Wallia cinerea_, Alefeld, 1861.

=Varieties of the Butternut.=--There are to be found many varieties of the butternut, varying mainly in the size of the nuts, and only slightly in the thickness of the shell; but I am not aware that any of these have ever been propagated, all the trees in cultivation or elsewhere having been grown from the nuts. This nut is, no doubt, susceptible of great improvement, as well as others of the genus, and it is worthy of being experimented with for that purpose, especially in cold, northern climates, where there are few or no other kinds of edible nuts. Probably the most direct and surest way to secure improved varieties is by hybridizing, taking the butternut for the female parent, and the Persian walnut for the male. Hybrids between these two species are already known, and they will, no doubt, become more plentiful as soon as skillful horticulturists are encouraged to produce them. Several hybrid walnuts of other species are figured and described by European horticulturists, but, so far as known, they are mainly accidental productions, and not the result of any direct effort of man; nature, in this instance, merely giving a hint of the possible, leaving us to avail ourselves of the lesson if we feel so inclined.

J. Le Conte, in a list of four hundred and fifty plants, collected by him on the island of New York (Manhattan), and published in the "Medical and Philosophical Register," Vol. II, 1812, mentions a hybrid walnut among the number. Dr. John Torrey, in "Catalogue of Plants," etc., 1819, refers to this tree under the name of _Juglans hybrida_, and says that it is growing near where Eighth avenue intersects the road called Lake Tours, about three miles from the city, and is a large tree. This specimen probably disappeared long ago, and we have no means now of determining its origin or between what two species it was a hybrid.

Recently Prof. C. S. Sargent has discovered other hybrid walnuts in the neighborhood of Boston, and figured and described one in _Garden and Forest_ for Oct. 31, 1894. He says:

"My attention was first called to the fact by observing that a
tree which I had supposed was a so-called English walnut
(_Juglans regia_), in the grounds connected with the Episcopal
school of Harvard college, at Cambridge, was not injured by the
cold of the severest winters, although _Juglans regia_ generally
suffers from cold here, and rarely grows to a large size. This
individual is really a noble tree; the trunk forks, about five
feet above the surface of the ground, into two limbs, and
girths, at the point where its diameter is smallest, fifteen
feet and two inches. The divisions of the trunk spread slightly
and form a wide, round-topped head of pendulous branches of
unusual symmetry and beauty, and probably sixty to seventy feet
high. A closer examination of this tree showed that it was
hardly to be distinguished from _Juglans regia_ in habit, in the
character of the bark, or in the form and coloring of the
leaves, and that the oblong nut, with its thick shell deeply
sculptured into narrow ridges, was the slightly modified nut of
our native butternut, _Juglans regia_. Two other trees with the
same peculiarities were afterwards found. One is a large,
wide-spreading specimen, with a trunk diameter of four feet
three inches about two feet above the surface of the ground, and
just below the point where it divides into three large limbs.
This is on the grounds of Mr. Eben Bacon of Jamaica Plain, and
is supposed to have been planted between fifty and sixty years
ago. The other has a tall, straight trunk, with a diameter of
three feet one inch at three feet above the surface of the
ground, and is growing on a farm near Houghton's Pond, in
Milton, at the base of the southeastern slope of the Blue
Hills."

That there should be hybrid walnuts is nothing strange or wonderful, and we often marvel that there should be so few of them in regions where two or more species are growing in close proximity in the same forest, or elsewhere, but from whence came these specimens in Massachusetts is somewhat of a mystery. We may safely conclude, however, that the hybridizing did not occur there, but somewhere else, and either the nuts or small seedling trees were introduced and planted where these hybrid specimens are now growing. It is possible that they are descendants of the old hybrid walnut tree of New York city, mentioned by Le Conte and Dr. Torrey, some one having sent nuts or seedlings to friends in Massachusetts, and the three trees described by Prof. Sargent are merely those which have survived until the present day, these retaining the hybrid characteristics of their parent. These hybrids may or may not possess any special economic value, but they are of considerable scientific interest, and for this reason alone are well worthy of careful preservation and extensive propagation.

_Butternut Sugar._--It has often been claimed that sugar can be made from the native butternut tree, and while it is true that the sweetish sap flows readily from wounds made in this tree in early spring, the amount and quality of sugar to be obtained from it is scarcely worthy of serious attention. In my boyhood days butternut syrup and sugar were considered as "sticky jokes" of the sugar camp.

_J. regia_ x _J. Californica_.]

=Hybrids in California.=--Mrs. Ninetta Eames, writing, in the _American Agriculturist_, of new varieties of walnuts in California, refers to certain species and varieties growing in that State, as follows:

"On one of the avenues in Santa Rosa there are some dozen or so
ornamental shade trees, which invariably attract the passers. It
is not only that they are uncommonly beautiful, but that there
is something unfamiliar about them. One unhesitatingly
pronounces them 'walnuts,' from their unmistakable likeness to
both the English walnut and the native species found growing
along the streams of middle and southern California. They are,
in fact, a cross between the _Juglans regia_ and _J.
Californica_, the wild black walnut of this State. In its
appearance, this magnificent hybrid is nicely balanced between
both parents, but it is superior to either of them in beauty and
luxuriance of foliage, and in its phenomenal growth. There is,
indeed, but one tree, the eucalyptus, that grows more rapidly.
In speaking of this quality in the new walnut, Mr. Luther
Burbank says: 'It often excels the combined growth of both
parents, adding twelve to sixteen feet to its hight in one year.
Given like conditions, a budded six-year-old hybrid is twice as
large as a black walnut at twenty years of age.'

"The clean cut, bright green leaves make a remarkable showing,
being all the way from two feet to a yard in length, and of
graceful, drooping habit (Fig. 77). They are sweet-scented,
too,--a delightful fragrance, resembling that of June apples.
Another admirable feature of this hybrid walnut is its smooth,
grayish bark, with white marblings not unlike the Eastern sugar
maple. The wood is compact, with lustrous, satiny grain, and
takes an elegant polish, which gives it unmistakable commercial
value. Like the majority of hybrids, though blossoming freely it
yields a scant crop of nuts, one or two annually on a single
tree, and this only after twelve years of persistent barrenness.
The seed, when planted, goes back to its parent
distinctiveness,--one-half turning out to be English walnuts and
the other half black walnuts,--the true hybrid being only
reproduced by grafting on a thrifty young _Juglans Californica_.

"Another handsome novelty in shade trees, is a hybrid from the
_Juglans nigra_, or well-known Eastern black walnut, and _J.
Californica_ (Figs. 78 and 79). It makes a charming ornamental
tree, and bears, in its season, a prolific crop of unusually
large nuts, which have little value except in the eyes of school
children. Several of these hybrids are growing in Santa Rosa,
and present an interesting study to the pomologist.

"A still more unique species of the walnut genus is the _Juglans
Sieboldiana_, a Japanese walnut which grows abundantly in the
mountainous districts of the island of Yesso, and also in the
more southern divisions of the empire. Several of these
remarkable trees are to be found in the Kew gardens, but only
one specimen is said to be growing in America, and this has
recently come into profuse bearing on the Burbank experimental
farm, eight miles from Santa Rosa, California. According to good
authority, this Japanese walnut not only attains its greatest
perfection in this favored climate, but it thrives equally well
in countries too cold for the common walnut, _J. regia_. In its
wild state in Japan, the _Juglans Sieboldiana_ (whose curious
raceme of nuts is shown in Fig. 80) makes a wide-spreading tree
about fifty feet in hight, with pale, furrowed bark; nuts an
inch and a half long, with a diameter one-third less, and a
kernel having much the flavor of the common walnut. The tree
bearing so thriftily on California soil, suggests its possible
value as a marketable nut, while it already furnishes a
remarkable addition to horticultural interests."

JUGLANS NIGRA, Linn. Black Walnut.--Leaflets eleven to seventeen, rarely more; ovate-lanceolate, smooth above, moderately pubescent beneath, pointed, somewhat heart-shaped at the base; leaf-stalks slightly downy, usually of a pale purplish color early in the season, especially on young trees; fruit large, mostly globose (Fig. 81); husk thin, roughly dotted; shell thick, hard, deeply and unevenly corrugated with rough, sharp ridges and points (Fig. 82); kernel large, sweet, but usually with a strong, rather rank taste, but less oily than the butternut. Trees grow to an immense size, with deeply furrowed bark; wood dark colored, valuable for cabinet work, inside finishing, gun stocks, etc. Common in deep, rich soils, from western Massachusetts west to southern Minnesota, and southward to Florida. Most abundant west of the Alleghany mountains, and especially in the rich valleys of the Western States distant from railroads and water communication; elsewhere the trees have long since been cut for their timber. I have only one synonym to record, and this is scarcely worthy of notice, viz.: _Wallia nigra_. (Alefeld in "Bonplandia," 1861.)

=Varieties of the Black Walnut.=--As with the butternut, there are no varieties of the black walnut in cultivation; at least, none propagated by means which will insure the perpetuation of their varietal characteristics. It is true that there are plenty of wild varieties to be found, these varying widely in size and form, and somewhat in thickness of their shell, as well as the ease with which the kernels may be extracted, but none of these have been perpetuated by artificial means. Among the earliest varieties recognized by botanists, one was called Oblong Black Walnut, _Juglans nigra oblonga_, by Miller, 1754, and perhaps in earlier editions of the "Gardener's Dictionary." He says this is from Virginia, and only a variety of the common black walnut. Marshall, in 1785, describes this "black oblong fruited walnut," and adds: "There are, perhaps, some other varieties." These oblong, or, more correctly speaking, oval nuts, often sharp-pointed at both ends, are rather plentiful at this time. There are rarely any considerable number of bushels reaching market from Virginia and adjacent States, among which these oval or oblong nuts cannot be found. I have a number before me measuring from one inch to one and a quarter in diameter, and from one and a half to nearly two inches in length. Other varieties found, perhaps, in the same lot, are broader than long, or one and seven-eighths inches broad, by one and one-half in vertical diameter. These measurements are of the cleaned shell, after the husks have been removed.

For several years a "thin-shelled black walnut" has been offered by at least two nurserymen, in whose catalogues they are described as "with unusually thin shells, the kernels coming out whole." I have endeavored to ascertain the origin of this variety, but failed, for both of the nursery firms who advertised the frees for sale admit that they do not know from whom they obtained the nuts planted, or where the original tree is growing. As the trees offered are only seedlings, there is no certainty that they will produce nuts with "thin shells." We can safely drop this supposed variety from the list until something definite is known about it.

JUGLANS CALIFORNICA, Watson. California Walnut.--Leaflets in from five to eight pairs, more or less downy, but sometimes smooth, oblong-lanceolate, sharp-pointed, narrowing upward from near the base, two to two and a half inches long. Male catkins much larger than in our Eastern species, or from four to eight inches, often in pairs. Fruit round, slightly compressed, three-fourths to one inch and a quarter in diameter; husk thin, slightly dotted or roughened; shell dark brown, very faintly sculptured (Fig. 83), almost smooth, thick, the kernel filling two broad cavities upon each side; edible and fairly good. A tree or large shrub in the vicinity of San Francisco and along the Sacramento (where it is sometimes cultivated), growing to the hight of forty to sixty feet, and two to four feet in diameter; ranging southward to Santa Barbara, and eastward through southern Arizona to New Mexico and Sonora (Thurber, "Botany of California"). This species has been considered by some botanists as only a variety of the next, or _Juglans rupestris_, var. _Major_, Torrey. Scarcely hardy in the latitude of New York city, except an occasional seedling from nuts gathered along the northern limits of the species, or from the cooler elevated regions of the Pacific slope. It is of no special value, only adding one more edible nut tree to the list.