The Olive Its Culture in Theory and Practice/Chapter 8
Preparation of the Ground
CHAPTER VIII.
The selection of the spot for an olive orchard having been made, the surface should be cleared of all woody plants and roots, and then plowed as deeply as possible. If the plowing can be done with the first rains, say in November, and the ground left exposed to the elements till planting time comes, which should be after all danger from frost has past, it will receive an atmospheric fertilization which will be so much gained. But let the plowing be deep, twenty inches if possible, remember that centuries may pass before it can be done again. Any expense incurred in this direction is money well laid out, and will pay for itself many times in opening the way for the perfect rooting of the future olive.
On the other hand, shallow plowing and a dry season might well result in young olives casting their leaves and fruit, from the impos-possibility of the young rootlets penetrating the hard unbroken soil.
The plowing finished, the holes for the trees are next in order, these may be of various shapes, square, rectangular, and lastly the trench.
Of the holes, the square is the best, and to obtain the very best result should be three feet deep, and three feet wide at the surface. If the ground in question has not at least a yard of soil, the olive will not flourish there, as when the tap root encounters an obstruction it bends up and the lateral roots develope in its place, and as the growth of the tree is always equally proportioned between its root system and its branches, the obstacle encountered by the pivot roots becomes immediately apparent in the appearance of the tree. The stem, which corresponds to this root, ceases to grow with its previous vigor and force. The trunk loses its smooth, ash colored bark, and its base is covered with a variety of protuberances, which bulge out and indicate the disproportioned circulation of the sap. So the appearance of a tree alone indicates whether the soil is a congenial one or not. But the straight stem, smooth, ash colored bark on the trunk, green bark on the branches, a round and exactly proportioned top is only to be expected from a tree raised from seed.
Fig. 4.
PLANTING OF THE YOUNG TREE. ONE METRE IN DEPTH.
d. Layer of stones and sticks.
e. Strata of earth upon which the roots rest.
f. Strata surrounding the root system.
c. Central part underlying the root, which should consist of well worked earth.
g. The plant itself interred as it stood in the nursery.
In the bottom of the hole put a layer of stones and branches mixed, in order that the drainage and ventilation may be perfect. In many dry soils, of course this would be entirely unnecessary, and in setting out an orchard on a large scale, would add very greatly to the expense, and is only indicated here in order to show to what perfection the transplantation may be carried.
At the same time, we do not think that any money expended on these preparatory labors will be thrown away, but believe that the future will largely recompense them. Let then the layer of stones and branches fill the bottom of the hole to a depth of six inches, and on top of this, a layer of well aired good soil. If the soil is sticky, it is well to mix it with such mineral ingredients as ashes, sand, or lime. In loose soil clayey material should be used instead. In both cases it is advantageous to place under each plant a few shovelfulls of old, well fermented manure, then the plant itself, and if water is to be conveniently had, five or six gallons can be used to advantage in settling the roots. The ground immediately below the roots should be composed of soft, loose earth mixed with manure, for this is the part first to embrace the young and tender fibers, and from which, they will radiate into the more compact earth, as they gather strength. When the planting of the tree is complete, a stake is driven by its side and secured to it by a cord, but to guard against injury to the delicate bark, a wisp of straw should be placed under the cord.
Except where the soil is sandy and loose, or subject to persistent dryness, the plants should not be set deeper than sixteen inches.
It is shown by observation that the volume of a piece of ground worked over decreases one twelfth in a year, by the progressive diminution of the porosity. Thus a hole dug to a depth of one yard with sewerage of eight inches, and covered evenly, would at the end of a year have sunk three inches, and the plant placed in the hole would have sunk proportionately.
It follows then, that a plant placed in its accompanying sod, in level ground, will at the end of a year be three inches deeper than when put out. Planting at more than the ordinary depth will be injurious to the plant, and will often cause its death. For the perfect development of the olive, the soil must be pervious to the air, which is indispensable to the respiration of its whole organism.
Experiments have shown how the development of the same plant can be retarded or advanced, by planting it alternately deep and shallow. From these experiences it is conclusive that to condemn the olive to too great a depth in the ground is a grave error.
The rectangular hole of two feet long, and two feet deep, and a foot wide, will probably be the one commonly used in California, as it is much the cheapest.
Instead of holes a continuous trench may be dug, not less than three feet in depth; and the trees set out in it at the proper distance apart. Here the tender roots encounter no obstacle, the trench giving them free play each way and the result is, an astonishing development of the young tree. These trenches have proved particularly good on side hills. When we reflect that the life of this tree that we are starting on its road, will cover centuries, any expense incurred in promoting its growth at the beginning seems slight in comparison.
The wild seedling olive is unknown in California, but as the seed of the cultivated type almost invariably produces that of the wild, not many years will pass before these will begin to spring up on the hills about our valleys. The birds will be the disseminators. The writer has noticed the robin in particular. On cold winter days in the Santa Clara valley, this bird leaves the hills and appears on the Quito Olive Farm in great numbers, eating any fruit that offers itself, olives among others. The Spaniards are led to claim that the olive is indigenous to Spain because it is found growing wild on all their mountains, perhaps some future Californian will make the same claim for us, for the seed of the olive will certainly be spread far and wide in this way.
The olive orchard should be plowed or cultivated at least four times during the year, but not to a greater depth than five inches, or the surface roots may be injured.
As soon as the berries are picked which may be in December, January or February, the tree rests. Its labors have not been light in sustaining and nourishing its burden of fruit so long. As soon as it is relieved of its heavy load it begins to recuperate and prepare for the following May when it will blossom again. The orchard should first be pruned and cleaned, and then plowed in order to give the trees the greatest possible assistance.
To keep down the weeds, it will be necessary to plow again before flowering time arrives, but on no account should any cultivation be attempted while the olives are in flower, as the exhalations from the ground, caused by turning over the soil, are very prejudicial to the tree when in this condition. Until the flower has withered and fallen off and the new berry has formed, nothing should be done that would cause any emanations from the soil.
The olive buds first, then flowers, fecundation becomes complete when the pollen comes in contact with the flower eggs, to which it communicates the power of freeing the embryo and transforming itself into seed. To judge whether this has successfully taken place or not, an inspection of the withered blossoms under a tree will demonstrate. If the corolla only has fallen, making a flat, star-shaped flower with a well defined hole in the center, all is well; but if the pistil is attached to it, then fecundation has not taken place and the crop has aborted. This may happen from a variety of causes, and it is the critical period to the olive grower. Too great heat, a late frost, excess of rain, heavy winds, a lack of certain necessary elements in the soil, or an excess of these, may singly or in combination, bring about this untoward result. The first, or too great heat at the time of blossoming, will probably be the source of greatest danger to the California grower. The olive in flower is said to be able to endure a temperature of one hundred and seven degrees Fahrenheit, without receiving any damage. One hundred and ten degrees Fahrenheit proved injurious to the prospect of a crop on the Quito Farm in May, 1887, cutting down by two-thirds what promised to be an unusually large yield. It is the still, burning heat that does the harm. For this reason, rising ground or the middle hills are sought for the olive, where it may get the benefit of every passing breeze.
It is a sign of good fructification when the tree covers itself with blossoms to its very summit, as it proves its capacity to nourish flowers so far from the trunk. The flowers having fallen and the new berries formed, the olive orchard should be cultivated for the third time, and still again in the early part of September. The ground immediately about the trees should be dug over with the split spade or earth fork, taking care not to injure the lateral roots which lie near the surface.
TRANSPLANTATION.
Care should be taken in transplanting young trees to convey with them as much of their native earth as possible, some laceration of the delicate capillaries is unavoidable. A spade is the proper tool to use. If the tree is then kept for twenty, thirty, and even forty days in a dark place, it will be found to be exceedingly beneficial to it. The activity of the functions of the plant having been greatly diminished in the leaves, the root system is correspondingly stimulated, and will produce new shoots, which by their absorbing power, will contribute greatly to the vigor of the young plant. The breaking of the extreme ends of the roots, occasions no harm since the absorbent surface of the roots is confined to the parts provided with hairs, which are found in the middle of the young fibers. The exposure of the extreme ends or even cutting them, will not affect the freshness or vigor of the plant, but if the middle part be wounded, the injured fibers should be cut off immediately, in order that the sound part may not suffer by contact.
From the cut, new and numerous roots will spring, and for this reason the top of the plant should be thinned out, in order to maintain the equilibrium between the parts above and below ground. The pruning should be from the year old branches or two years old at most. The topping of the trees is proper in two cases only.
First: When the root system, not having been properly protected, has been robbed in great part of the capillaries, which are intended for its nourishment from the soil.
Second: When the plants have been crowded in the nursery, and have long slender trunks, and are likely to be exposed to high winds.
In transporting the tree without sod about the roots, which is the custom where any distance is involved, it is necessary to top the tree to offset the loss suffered by the roots.
"A tree topped,
Is a tree insured."