Reprinted from Cyclopedia of American Horticulture by Liberty Hyde Bailey, 1902
Notwithstanding the high esteem in which the nuts of several species of Hickory have been held since the settlement of America, but little progress has been made in their domestication and improvement. Out of the 9 or 10 species recognized by botanists, not more than 3 or 4 have been found sufficiently promising from an economic standpoint to justify conspicuous effort at amelioration. Of these the Pecan (H. Pecan) stands easily first, followed in order of apparent value by the Shagbark (Little Shellbark), H. ovata; the Shellbark (Big Shellbark), H. laciniosa, and the Pignut, H. glabra. The Pecan differs in its requirements of soil and climate from the other species, and is described separately under Pecan.
In flavor and quality of kernel the Shagbark is esteemed by most Americans as the choicest of native nuts, though in these respects the Shellbark is but little inferior to it. The thinner shell and larger proportion of kernel have given the former precedence over the latter in most cultural efforts; though the thrifty growth, symmetrical form and luxuriant foliage of the latter render it one of the most handsome and useful of native trees for roadside or lawn planting. The Shagbark has the broader area of natural distribution, being found in localities throughout most of the United States to the eastward of the Great Plains, except on the lowlands of the South Atlantic coast and Gulf states. The Shellbark is mainly confined to the valley of the Mississippi and its larger tributaries, extending eastward, however, into eastern Pennsylvania and western New York.
The Pignut, which is similar to the Shagbark in area of distribution, is much inferior to the others in quality, but shows wider variation than either in this respect, and has disclosed at least one variety of distinct cultural merit.
As the Hickories, other than the Pecan, are slow-growing species at best, they should not be planted on other than fertile soil. The Shellbark is native to river bottoms, and requires richer land than the others, which endure a rather wide range of soil characteristics, provided there is sufficient depth and good drainage. Deep, well-drained, fertile loams, either of sandy or clayey nature, are acceptable to all the species.
Propagation. – All the species are propagated by seed. Planting is frequently done in autumn, but, to lessen the destruction by rodents, is more safely done in early spring. In such case the freshly gathered nuts, after removal from the hulls, should be stored in slightly dampened sand during the winter, or stratified, as other tree seeds. Uniformity of growth is promoted by planting nuts where trees are to stand, as the transplanting process in ordinary seasons is accompanied by a considerable loss. If trees must be transplanted, it is probably best to transplant annually in nursery rows, in rich soil, to promote growth of fibrous roots and to lessen the shock of final transplantation to the permanent location.
The propagation of the Hickories by budding and grafting is exceedingly difficult, even the most experienced propagators of woody plants failing to secure more than a small percentage of success. Most growers favor cleft crown-grafting in the spring, on established stocks of the same species. The operation is performed just as stocks are starting into growth, using dormant cions with terminal buds and mounding up to the top bud with fine earth. As the stocks are in condition only for a few days, the process is uncertain and expensive.
One of the most successful propagators of woody plants, Jackson Dawson, of Arnold Arboretum, recommends the use of the Bitternut (H. minima) as a stock, growing seedlings in boxes 4 in. deep for one or two years, until of sufficient size for grafting. Under this plan the seedlings should be transferred to pots in the autumn and taken into the greenhouse about January 1. He advises side-grafting these close to the collar. As soon as the roots begin to start, the grafted trees in pots must be plunged in sphagnum to the top bud and left until March to callus. Root-grafting, as commonly practiced, has rarely been found to succeed.
One promising method of root-propagation suggested by Fuller consists in the “turning up or exposing at the surface of the ground of side roots, severed from the parent tree.” Their lower extremities are left in place for one or two seasons, until a distinct top has been formed through the agency of adventitious buds on the exposed portions. Through a slow and expensive process, this is probably more certain than any other method yet developed. In some instances, where the tops of trees have been killed, the varieties have been perpetuated through this practice by promptly turning up and staking roots that were yet alive.
Planting should be done in autumn, or as early in spring as the ground can safely be worked. An abundance of rich soil should be used in the holes, as much of the success in transplanting depends upon a prompt and vigorous root-growth. If clean cultivation cannot be practiced, a heavy mulch should be applied, and be maintained for several years, until the tree is well established. After this, little care is needed, except to guard against the attacks of leaf-eating insects.
Production and Use. – Large quantities of Shagbarks are consumed in our cities, but the supply is mainly from the forests.
In some sections, choice second-growth trees have been preserved along fences and roadsides, and these are usually found to yield larger crops and finer nuts than the forest trees. In portions of southeastern Pennsylvania there is a large production of nuts from such trees. In that section the nuts are marketed in the form of kernels free from shells, for use by confectioners and bakers. The cracking of the nuts is done by women and children on the farms, this work constituting a domestic industry of some importance at certain seasons. As the use of Shagbarks in cooking is apparently increasing, it is important that trees bearing choice nuts shall be preserved and cared for. The characteristics that determine commercial value are: first, cracking quality; second, thinness of shell; third, size; fourth, plumpness and flavor of kernel; fifth, productiveness.
Numerous apparently natural Hickory hybrids have been brought to notice, but those thus far discovered have given little evidence of cultural value. The most important are the Nussbaumer and McCallister nuts, which are described under Pecan.
Varieties. – In consequence of the difficulty with which the Hickories are propagated by budding and grafting, few nurseries offer other than seedling trees. Several choice varieties of Shagbark have been described and named because of desirable characteristics, however, and several of these have been propagated in a small way by crown-grafting on established trees. Grafted trees of one variety, the Hales, can be obtained in small numbers at one or two nurseries. No varieties of the Shellbark have been offered by nurserymen.
SHAGBARK: Curtis. – Conn. A smooth nut of medium size, slightly compressed: kernel plump, light in color and of good quality: shell thin; cracking quality good.
Dover. – Pa. A medium-sized angular nut, rather broad at the base, but having a long and sharp basal point: shell moderately thin; cracking quality good: quality good.
Eliot. – Conn. Of medium size, compressed, angular, ovate, with prominent tip: kernel plump; flavor mild and pleasant: shell thin; cracking quality good.
Hales (Hale’s Papershell). – N.J. Large, quadrangular, slightly compressed, with a peculiar wavy surface: kernel rather deeply corrugated, but plump and of good quality, retaining its sweetness for two years or more: shell thin and of fair cracking quality. The Hales nut is the first named variety of Hickory, having been described and illustrated by A.S. Fuller in “The Rural New-Yorker” in 1870. It is probably the only sort now obtainable at the nurseries. The original tree bears a fair crop annually, and numerous younger trees grafted from it are now in bearing.
Jackson. – Ohio. A compressed oval nut of large size: kernel large, plump, and of excellent quality: shell thin; cracking quality medium.
Leaming. – Mo. A large nut of fine flavor and excellent cracking quality, the kernel coming out in unbroken halves.
Meriden. – Conn. Large, oblong, compressed: kernel large and of good quality: shell rather thick, but cracks well.
Milford. – Mass. A compressed ovate nut, medium to large in size, with large, plump kernel of excellent quality: cracks well: one of the best nuts yet brought to notice.
Rice. – Ohio. Angular, ovate, medium to large in size: kernel plump, bright and of fine quality: shell thin and of good cracking quality: tree regularly productive.
Woodbourne. – Pa. Long, compressed ovate, large and smooth: kernel tender and of very high quality: shell rather thick, but cracks well.
PIGNUT: Of the somewhat numerous sweet-flavored forms found in this species, the following one at least has been deemed worthy of perpetuation because of its delicate flavor, thin shell and excellent cracking quality.
Brackett. – Iowa. Roundish compressed, smooth and of grayish color, medium to large in size: kernel plump, sweet and of delicate flavor: shell very thin, and easily freed from the kernel.