The Nut Culturist / A Treatise on Propogation, Planting, and Cultivation of Nut Bearing Trees and Shrubs Adapted to the Climate of the United States

by Andrew S. Fuller

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.

[FIG. 75]. SEEDLING WALNUT.

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."