Hickories though easily raised from imported nuts, require special treatment on account of their long thick tap-roots, which make them so difficult to transplant; and as they grow slowly for several years and do not ripen their wood when young, in most places, their ultimate success must always be to some extent a matter of chance. Though they are found in America, in places where the soil is not specially deep or good, they require a hotter summer than we get to enable them to ripen fruit, and when a tree will not ripen seed, it can hardly be called acclimatised.
I have made many experiments in raising them from seed, which at present have not given very good results, principally, I think, because of unfavourable local conditions; but believe that if the following points, which are based on those adopted in the Arnold Arboretum,[1] are attended to, the trouble will not be thrown away.
The nuts must be procured from America as soon as ripe; and if there is any influence in heredity, as I believe there is, from the Northern, rather than from the Southern or Western States; but it is only fair to say that the seed which I collected myself in Canada and near Boston, did not produce such strong seedlings the first season as those which I procured from Philadelphia.
The nuts should be sown at once in boxes of about 18 to 24 inches deep in rich sandy loam, about 2 inches apart, and covered with an inch or so of light soil. The boxes may be stored for the winter in a shed, and in spring brought into a frame or greenhouse to induce earlier germination. They should be kept under glass until all risk of spring frost has gone by, and perhaps are better kept in a frame the whole summer lightly shaded, and watered when necessary. The leaves will remain on throughout the autumn, when the box should be exposed to the full sun; and as soon as the shoot, which does not exceed 4 to 8 inches in height the first year, is ripe, may again be put away for the winter in a dry place covered with leaves, and protected from mice.
In the following May the seedlings may either be turned out and planted in a deep rich nursery bed, after cutting off the tap-root at about a foot, or if a warm sheltered spot can be found in a wood, where they can be cultivated and sheltered for some years, they may be planted out permanently without cutting the tap-root. But as the danger from vermin and early or late frosts will continue for some years, it may be better to keep them in the nursery till they are 3 to 5 feet high, provided that when transplanted a deep trench is first made on one side, so as to get up the whole of the root with as little injury as possible. Woods being their natural home they are more likely to grow into good trees when drawn up with others than when exposed in the open; but we cannot point to an instance in Great Britain where they have been so treated, though some of the best trees we know are in dense shrubberies.
As regards soil, it cannot be too deep, rich, or well drained, and a southern or western aspect is to be preferred. Under such conditions they may attain 50 to 60 feet in height in as many years, and in some parts of England even more. A certain amount of lime in the soil does not seem to be harmful.
The hickories are not either in America or in England very long-lived trees,
- ↑ Cf. Garden and Forest, x. 116 (1897).
