When the flower buds begin to open, the forcing must be conducted more slowly and evenly, so as to give the delicate organs time to perfect; but after the fruit is set, the heat can be increased till it occasionally reaches 75 degrees at midday. After the fruit begins to color, give less water—barely sufficient to prevent any check in growth, and the fruit will be sweeter and ripen faster. The upper blossoms may be pinched off, so as to throw the whole strength of the plant into the lower berries. Keep off all runners; syringe the plants if infested with the red spider, and if the aphis appears, fumigate him with tobacco.
The plants that have fruited need not be thrown away as useless. If they are turned out of the pots into rich, moist soil, in April, and the runners are kept off all summer, they will make large, bushy stools, which will give a fine crop in autumn.
The amateur, with a small conservatory or south window, by approximating as far as possible to the conditions named, can achieve a fair success. I have had plants do moderately well by merely digging them from the beds late in the fall, with considerable rich earth clinging to their roots, and then potting with more rich soil, and forcing them at once. Of course, fine results cannot be expected from such careless work, but some strawberries can be raised with very little trouble. If one, however, wished to go into the business on a large and scientific scale, I would recommend a straw berry-house, designed by Mr. William Ingram, gardener at Belvoir Castle. A figure of the structure may be seen on page 74 in Mr. Fuller's valuable work, "The Small Fruit Culturist." On the same principles that we have been describing, the ripening of strawberries can be hastened by the use of hot beds, cold frames, and ordinary sash.
During the Christmas holidays strawberries sell readily at from $4 to $8 per quart, and handsome fruit brings high prices till March; but the profit of raising them under glass threatens to diminish in future years, since Florida berries begin to arrive freely even in February. There are those who now seem to be doing well in the business of forcing, if we may judge from the jealousy with which they guard the open secrets of their calling from their neighbors.
A rough and ready method of forcing is to dig up clumps of plants during a mild spell in winter or early spring, put them in boxes or pots of rich earth, and take them into the green-house. Considerable fruit is sometimes ripened in this way.
An English writer says: "We find forced strawberries mentioned as being served at an installation dinner, April 23d, 1667; but the idea had already occurred to the great Lord Bacon, who writes, 'As we have housed the exotics of hot countries, so we may house our natives to forward them, and thus have violets, strawberries, and pease all winter.'"
CHAPTER XVIII
ORIGINATING NEW VARIETIES—HYBRIDIZATION
This chapter introduces us to great diversities of opinion, and to still greater differences in experience; and I fear that I shall leave the subject as indefinite as I find it. The scientist best versed in botany and the laws of heredity can here find a field that would tax his best skill for a lifetime, and yet a child may amuse himself with raising new kinds; and it would not be impossible that, through some lucky combination of nature, the latter might produce a variety that would surpass the results of the learned man's labor. As in most other activities of life, however, the probabilities are on the side of skill and continuous effort.
We have already shown that all the seeds of the F. Virginiana and F. Chilensis may produce a new variety. These seedlings often closely resemble the parent or parents, and sometimes are practically identical with one of them; more often they present distinct differences. It is wholly impossible to predict the character of seedlings as they usually are produced. If we could obtain pure specimens of the two great species, and cross them, the element of chance would not enter into the result so largely as must be the case when seed is gathered in our gardens. The pedigrees of but few varieties are known, and in many instances the two great races are so mingled that we can only guess which element predominates, by the behavior and appearance of the plants. The kinds with which we start are hybrids, and, as Mr. A. S. Fuller sagaciously remarks, "Hybridizing, or crossing hybrids, is only mixing together two compounds, the exact proportions of neither being known." Therefore, the inevitable element of chance. Disagreeable traits and shiftless ways of strawberry grandparents and great-grandparents may develop themselves in a seedling produced by the union of two first-class varieties. At the same time it is possible that fine ancestral qualities may also assert themselves. The chance seedling, which comes up in a garden where good varieties have been raised, may prove a prize. The Forest Rose was found growing in a vineyard. If we propose to raise seedlings, however, we will, of course, select seeds from the best fruit of fine varieties, even in our first and most rudimental efforts. Before making any serious or prolonged attempt to originate new varieties, it would be well to familiarize ourselves with certain principles, and gather experience from the successes and failures of others. We have seen that the F. Virginiana is the native species of the eastern section of our continent, and that its vigor and hardiness best adapt it to our extremes of climate. It were best to start, therefore, with the most vigorous strains and varieties of this hardy species. It is true that fine results can be obtained from crossing varieties of the F. Chilensis with our native species—the President Wilder proves this—but few of such products are adapted to the country at large, and they will be almost sure to falter on light soils. We will achieve our best success in developing our native species. By observation, careful reading of the horticultural journals, and by correspondence, the propagator can learn what varieties show vigor and productiveness throughout a wide range of country, and in great diversities of soil and climate. These sturdy kinds, that seem bent on doing well everywhere, should be the robust forefathers of the strawberries of the future. Starting with these, we are already well on the way toward the excellence we hope to attain. The pith of our difficulty now is to make any further advance. How can we surpass that superb group of berries that prove their excellence year after year?