It is recommended,[2914] also, that the dung-heap should be kept in the open air, in a spot deep sunk and well adapted to receive the moisture: it should be covered, too, with straw, that it may not dry up with the sun, care being taken to drive a stake of robur into the ground, to prevent serpents from breeding[2915] there. It is of the greatest consequence that the manure should be laid upon the land while[2916] the west winds prevail, and during a dry moon. Most persons, however, misunderstand this precept, and think this should be done when the west winds are just beginning to blow, and in the month of February only; it being really the fact that most crops require manuring in other months as well. At whatever period, however, it may be thought proper to manure the land, the greatest care should be taken that the wind is blowing due west at the time, and that the moon is on the wane, and quite dry. Such precautions as these will increase in a most surprising degree the fertilizing effects of manure.
CHAP. 9. (10.)—THE MODES IN WHICH TREES BEAR.
Having now treated at sufficient length of the requisite conditions of the weather and the soil, we shall proceed to speak of those trees which are the result of the care and inventive skill of man. Indeed, the varieties of them are hardly less numerous than of those which are produced by Nature,[2917] so abundantly have we testified our gratitude in return for her numerous bounties. For these trees, we find, are reared either from seed, or else by transplanting, by layers, by slips torn from the stock, by cuttings, by grafting, or by cutting into the trunk of the tree. But as to the story that the leaves of the palm are planted by the Babylonians, and so give birth[2918] to a tree, I am really surprised that Trogus should have ever believed it. Some of the trees are reproduced by several of the methods above enumerated, others, again, by all of them.
CHAP. 10.—PLANTS WHICH ARE PROPAGATED BY SEED.
It is Nature herself that has taught us most of these methods, and more particularly that of sowing seed, as it was very soon evident how the seed on falling to the ground revived again in germination. Indeed, there are some trees that are capable of being propagated in no other way, the chesnut[2919] and the walnut, for instance; with the sole exception, of course, of such as are employed for coppice wood. By this method, too, as well as the others, some trees are propagated, though from a seed of a different nature, such, for instance, as the vine, the apple, and the pear;[2920] the seed being in all these cases in the shape of a pip, and not the fruit itself, as in that of the chesnut and the walnut. The medlar, too, can also be propagated by the agency of seed. All trees, however, that are grown by this method are very slow in coming to maturity,[2921] degenerate[2922] very rapidly, and must often be renewed by grafting: indeed, the chesnut even sometimes requires to be grafted.
CHAP. 11.—TREES WHICH NEVER DEGENERATE.
On the other hand, there are some trees which have the property of never degenerating, in whatever manner they are reproduced, the cypress, palm, and laurel,[2923] for instance: for we find that the laurel is capable of being propagated in several ways. We have already made mention[2924] of the various kinds of laurel; those known as the Augustan, the baccalis, and the tinus[2925] are all reproduced in a similar manner. The berries are gathered in the month of January, after they have been dried by the north-east winds which then prevail; they are then kept[2926] separate and exposed to the action of the air, being liable to ferment if left in a heap. After this, they are first seasoned with smoke, and then steeped in urine, preparatory to sowing.[2927] Some persons put them in baskets of osier, and tread them down with the feet in running water, until the outer skin is removed, as it is found that the moisture[2928] which they contain is detrimental to them, and prevents them from germinating. A trench is then dug, about a palm in depth, and somewhere about twenty of the berries are then put into it, being laid in a heap: this is usually done in the month of March. These kinds of laurel admit of being propagated from layers also; but the triumphal[2929] laurel can be reproduced from cuttings only.
All the varieties of the myrtle[2930] are produced in Campania from the berry only, but at Rome from layers. Democritus, however, says that the Tarentine myrtle may be re-produced another way.[2931] They take the largest berries and pound them lightly so as not to crush the pips: with the paste that is thus made a rope is covered, and put lengthwise in the ground; the result of which is that a hedge is formed as thick as a wall, with plenty of slips for transplanting. In the same way, too, they plant brambles to make a hedge, by first covering a rope of rushes with a paste made of bramble-berries. In case of necessity, it is possible at the end of three years to transplant the suckers of the laurel and the myrtle that have been thus re-produced.
With reference to the plants that are propagated from seed, Mago treats at considerable length of the nut-trees—he says that the almond[2932] should be sown in a soft argillaceous earth, upon a spot that looks towards the south—that it thrives also in a hard, warm soil, but that in a soil which is either unctuous or moist, it is sure to die, or else to bear no fruit. He recommends also for sowing those more particularly which are of a curved shape like a sickle, and the produce of a young tree, and he says that they should be steeped for three days in diluted manure, or else the day before they are sown in honey and water.[2933] He says, also, that they should be put in the ground with the point downwards, and the sharp edge towards the north-east; and that they should be sown in threes and placed triangularly, at the distance of a palm from each other, care being taken to water them for ten days, until such time as they have germinated.
Walnuts when sown are placed lengthwise,[2934] lying upon the sides where the shells are joined; and pine nuts are mostly put, in sevens, into perforated pots, or else sown in the same way as the berries are in the laurels which are re-produced by seed. The citron[2935] is propagated from pips as well as layers, and the sorb from seed, by sucker, or by slip: the citron, however, requires a warm site, the sorb a cold and moist one.