Cultivation
The black walnut was first described by Parkinson,’ and was introduced into England by the younger Tradescant before 1656, as it is mentioned in the list? of the plants growing in his garden at that time. A tree was growing in Bishop Compton's garden at Fulham in 1688, according to Ray.’
The black walnut is easy to grow from seed, but, except the hickories, none is more difficult to transplant, on account of the long fleshy tap-roots which it forms at an early age, and which, when grown in the good deep soil which it likes, are at a year old often three or four times as long as the seedling itself. For this reason, unless special care is given to its treatment, it is not likely to become so fine a tree as when sown in situ, and, though I have successfully transplanted many at one or two years old, I would much prefer the other method.
Though the nuts ripen in England in hot summers, they are not so large, and do not, I think, produce such strong plants as those imported from North America, and, if possible, I should prefer to get them from trees growing in Canada or New England than from farther south.‘ The nuts are best sown when ripe, as if kept dry for some time, they either lose their germinating power or come up so late that they make weak plants. In any locality which is subject to late frosts it would be better to sow them in boxes at least two feet deep and plant them out when a year old, as like many exotic trees they do not ripen their young wood well, and are liable to be frozen back in winter or spring, which induces a bushy instead of a straight habit of growth.
As this tree requires to be well sheltered and drawn up by surrounding trees in order to form a tall and valuable trunk, it should be sown or planted in small deeply-dug patches in a rich wood, kept free from weeds and pro- tected from mice, rabbits, and boys, until the trees are six to eight feet in height, which they should be under favourable circumstances at four to six years after sowing.
All these difficulties have made the tree unpopular with nurserymen, who rarely care to grow trees for which there is little regular demand. But the great value of the timber, its rapid growth on suitable places, and its perfect hardiness when once established, give it, in my opinion, so much importance, that, however troublesome it may be in its early stages, it should be tried at least on a small scale as a timber tree in the warmest and best soils of the southern, eastern, and west midland counties. For further particulars of the nursery treatment of this tree see Cobbett’s Woodlands, Art. 553; or Arboriculture,’ iv. 7, July 1905. Cobbett,
1 Theatrum Botanicum, 1414 (1640).
2 Museum Tradescantianum, 147 (1656).
3 Historia Plantarum, ii. 1798 (1688)—no doubt the tree mentioned by Loudon as existing in 1835 (see p. 208).
4 But the question as to whether the seeds of trees grown in a comparatively cold climate produce hardier plants than seed from a warm one, is as yet unsolved; and Prof. H. Mayr of Munich, than whom there is no better authority, is inclined to believe that the differences which are observed in the comparative resistance to frost depend on the variable constitution of the individual plant rather than on inherited power.—Cf. H. Mayr, Fremdl. Wald. u. Park-bäume (Berlin, 1906).
5 A magazine of the International Society of Arboriculture; J.P. Brown, Connersville, Ind., U.S.A.
