Another reason has been assigned, with some probability, to the apparently greater liability to disease of larch now than formerly, namely, that the cones are often gathered too early, and exposed to too much heat in the kilns in order to extract them. The cone of the larch does not open of its own accord usually until spring ; often in this climate so late that the seedlings make little growth the first year, and the seed cannot be extracted without heat, or by breaking up the cones in a mill, which bruises and destroys many seeds; and in the climate of Scotland they do not often ripen so early or thoroughly as in the drier, colder, and sunnier climate of its native Alps: therefore it seemed to me desirable to make experiments with larch seed from abroad, in order to find out whether there was any real difference in the vigour of foreign and home-grown seedlings; and though my experience in this way now extends over fifteen years, I cannot say that I have solved the question.
On many occasions I have sown seed from Scotland, the French Alps, and the Tyrol, and have found that on my poor calcareous soil, which, though it grows larch very well, is not at all suitable for raising it, a large proportion of these seedlings from all sources either perished in infancy, or grew so slowly in the first two years that they were far inferior to seedlings raised in Scotland on a better soil and climate, and probably on manured land. But many of these weaklings have after- wards grown into robust young trees, and the difference in their liability to suffer from spring frost, which is their greatest enemy, is not sufficiently marked to enable me to form a sound opinion as to which are best.
What I have learnt, however, is that, though seedlings cannot be raised as cheaply or as rapidly at Colesborne as in a Scotch nursery, they are more satisfactory in other ways, because it is better to eliminate the weaklings before they are planted out than to have to replant them afterwards ; and I believe that the greater the risk of disease the more careful one must be, not only in the selection of seed, but also in their nursery management. Another point in favour of home raising is that the seedlings are not exposed in their younger stages to the extreme drying of the roots which arises from the careless way in which they are often lifted and packed by nurserymen, and from the long delays in transit on the railway ; and, finally, the trans- plantation in a private nursery is more carefully done, and the roots are better developed and more able to endure the severe check of final transplantation to a soil which is less favourable to their growth than that of the nursery.
Mr. J.P. Robertson, forester to the Duke of Devonshire at Chatsworth, writes me as follows with regard to the comparative hardiness of larch raised from native and foreign seed in 1903 :—
“We have two nurseries, one at an elevation of 900 feet, the other at about 600. In botha large quantity of larch from home seed have been put in this spring, while in each a break of the Tyrolese, 10,000 in number of similar size, has been placed. These last were from two different nurserymen. In both nurseries the home variety has suffered severely from the strong white frosts that we had in Easter week, while the Tyrolese in each case is practically untouched.”
But on inquiry in 1905 whether this apparent superiority was still the case, he wrote:—
