A Practical Treatise on Olive Culture, Oil Making and Olive Pickling/Chapter 2
CHAPTER II.
REPRODUCTION.
The olive tree is reproduced in different ways: by the seed, by the simple cutting, by the ramified cutting, by suckers that shoot from the trunk, and by the woody excrescences which form on the bark of the upper roots of old trees.
Let us begin with the reproduction by the seed. It must be first understood that an olive tree so grown has to be grafted, as it would otherwise remain a wild tree, giving thus but a poor and small product. On the other hand it is well known that through the medium of a seed a tree is more vigorous, has a more lasting power, resists better cold weather, and is less delicate on the choice of soil than those grown from cuttings. For all such reasons this is the mode most generally in use in the olive regions of Europe.
But when the olive tree is so robust by nature, so little scrupulous with regard to the choice of soil, enjoys such remarkable longevity, and has no excessive cold weather to fear in California, should it be raised by us from the seed instead of the cutting, when by the first mode we have to wait ten or twelve years for the product, as against four or five years by the second?
Moreover, grafting which becomes indispensable when the tree is raised from the seed, giving it thus additional vigor, can just as well, if so desired, be applied to the tree grown from the cutting without losing thereby the advantages derived from this last mode of reproduction.
Coutance, who pronounces himself in favor of the seed, tells us that the plant has to remain at least seven years in nursery, and that after being grafted it requires three more years before it begins to bear fruit.
Reynaud tells us also that he has seen in France, in the county of Ardeche, as also at Cannes and in the Hyera Islands olive trees raised from seed; that they were ready to be grafted, but that this result had required seven years. He however adds that the reproduction of the tree by seed has been found so slow that it seems puerile to have recourse to it.
Amoureux affirms that this method is of an excessive slowness and of very little practical use.
Charles Etienne and Liebault concur in saying that it is time and money lost to employ this method.
In Mr. Elwood Cooper's treatise on Olive culture we also find that when the tree is raised from seed it has to remain seven years in the nursery, but that when grown from the cutting it bears as early in Europe as it does in California.
Riondet explains to us how the young olive tree, raised from seed, develops always a long taproot, which constitutes its principal and often its only support; and that when transplanting it to permanent site, after a long stay in a nursery, the cutting of said tap-root, which then becomes indispensable, inflicts upon its system a serious injury from which it is likely to suffer for years.
It seems thus established that the olive tree grown from the seed—which is the method most generally followed in the regions of Europe where the severe winters experienced occasionally make it desirable to render the tree as hardy as possible—has to be kept about seven years in nursery, and that at its transplantation it will experience a severe check which will be the natural result of meddling with its tap-root, as also of cutting back its top.
Is it then at all surprising that a half generation should pass before the olive tree so produced reaches bearing? Many people who have not carefully studied olive culture seem to believe that this is an inevitable result. We shall see by further explanations that it is not.
Let us pass now to the consideration of the propagation of the olive by cuttings. We would state in common with Coutance, Amoureux, Riondet, DuBreuil, Reynaud, and many others, that a cutting coming from an olive tree that has been grafted, and of a good variety, needs no grafting. This operation is however necessary when the cutting from a grafted tree is derived from a point below the place where grafting was effected.
These cuttings can be made like those of a vine or any other cutting, only with this difference that the olive tree being an evergreen, one or more sets of leaves should be left on.
It is difficult safely to cut the large truncheons because, when taken from the tree or even when cut a little to freshen the butt-end at plantation, there is danger of crushing the bark, which has the eflfect of imperiling their starting and which, should they grow, may induce rot. To plant them directly in permanent sites is to run the risk of losing a great many, as has happened to several parties I could name. If, on the other hand, they are placed in nursery in preference to much smaller cuttings, their tap-root will be so developed, even only after a year of stay therein, that it will be necessary to cut it back when they are to be transplanted, which will reduce their ultimate chances of growth and will at least make them languid and sickly for a year or two. But, the smaller the cuttings are when placed in the nursery, the less will be the chances at transplantation within a year of disturbing their root system which will necessarily be less developed.
These smaller cuttings, from six to eight inches long, are generally raised in boxes under glass, where they take very readily; or in open ground in nursery when from eight to twelve inches long; but there their growth is very precarious. When ready for transplantation within a year the whole root system can be taken with the soil adhering to it and placed in the ground without disturbing it, and especially without exposing it to the air.
I consider this last point of great importance, for it is well known that all evergreen trees, whose vegetation is nearly always active, are of a very difficult transplantation. The slightest exposure of their roots to the air renders the starting in their new places very doubtful. Any one who has had occasion to transplant eucalyptuses, laurels, orange trees, etc., must be acquainted with this fact.
In support of this theory I extract the following, from a recent article of the Phœnix Herald, giving a few sensible hints on the setting out of an orange orchard:
"The greatest care must be exercised in transplanting the orange not to allow the small thread-like roots of the tree to become dry, for the moment they do so the tree is gone. The roots must be carefully dampened till the tree is safe in the ground. This is one of the most important items to be observed in transplanting."
The olive is just as delicate to handle as the orange tree, so that the older it is and the more developed its root system, the more danger it presents in transplantation, when even the most careful precautions will not always secure success.
The small trees, when one year old, will develop with astonishing vigor when planted in their permanent sites; their tap-roots will sink rapidly; they will stand, without suffering, drought and hot weather, and not more than one in every two or three hundred will fail to grow. Not only had I occasion to verify this, but I have also observed that when so planted, without experiencing any amputation of their roots and branches, they will overtake in life and vigor before two or three years those which, planted older and larger, have had to undergo the mutilations which are rendered necessary by their greater age and a consequently more developed root system.
Mr. W. G. Klee, in a bulletin of the University of California, says that the mode of reproduction by large cuttings is liable to several objections. He claims justly that there will never be so fine a root system developed as by starting the trees from small herbaceous cuttings. He recommends to take from young, growing trees, the young tops, when neither very soft nor perfectly hard, having three to four sets of leaves, and to put them in a little frame with sand, where they are to be given a few waterings during the course of a month. He states that in three or four months the little cuttings will have rooted, and in a few months more will be found ready to set out. He adds that olive trees planted in the Santa Cruz mountains were propagated in this manner, that they received no irrigation after setting out, and that they have formed a beautiful root system.
Mr. Frank A. Kimbal, of National City, San Diego County, tells us also, that he has in no case succeeded with large cuttings, and that he has obtained but meagre results in planting twenty inches deep. He tried with all kinds of cuttings, from three feet down to eight and ten inches only, and he finds the latter preferable.
The mode thus recommended by Mr. Klee, by Mr. Kimbal and others, is in perfect harmony with what I have done, and which has enabled me to obtain an excellent root system in less than a year. Having had frequent occasions to compare it with others, I do not hesitate to pronounce it as the one method capable of producing most vigorous trees, which, within four or five years, will be from ten to twelve feet high, and will begin to produce a few gallons of olives.
I have knowledge of the fact that several persons have planted olive cuttings in nursery, and have met but with very meagre results. I think I can give them possibly the reason for it.
The olive, as already said, is an evergreen tree. It has two very distinct yearly vegetations, one called the spring vegetation, the other the fall vegetation. It is thus, that under our fine and quite exceptional climate, where the winters are frequently very mild, its vegetation knows scarcely any cessation. If the cuttings are not taken from the tree during one of those short periods of comparative repose—which vary according to seasons—and are not placed in the nursery within a reasonable time, say from one to two weeks, there is danger of the vitality in most of them dying out, and the loss will easily reach thirty, forty, or even fifty per cent., and possibly still more. In this respect, the cuttings of the olive tree differ from those of the vine, which can be cut immediately after the fall of the leaves, when vegetation comes to a stand-still, and which can be kept buried in the ground until March or April, without interfering with their starting when spring comes.
For the reasons here suggested, it can be understood why those who have attempted to reproduce the olive tree from cuttings which were not recently cut from the tree, and who have performed that operation at a season of the year when the sap was too active, have realized such poor results. I know of some parties whose loss has reached 80 and 90 per cent., and two of them who did not succeed with a single cutting. I can see no other cause for it than the one I have just mentioned. Let us now pass in review other modes of propagation.
Cuttings can be made from the suckers that grow from the base of the tree, but if they are taken below the grafting point of trees raised from the seed they will have to be grafted.
The olive tree is also reproduced from the woody excrescences that form generally on the trunk of old trees. This mode of propagation which carries with it the mutilation of the trunk of a tree is possible only in the countries where old trees are to be found, while from young trees, of which there will soon be plenty in California, cuttings can be easily procured through the ordinary process of pruning, which thus proves beneficial to them instead of being a source of mutilation. This alone should be a sufficient reason for the general adoption in this country of so rational a mode of propagation.
As much as possible a dry soil should be selected for an olive nursery. Riondet tells us that in irrigable lands a finer growth may be obtained, but when those young trees are transplanted to a dry soil, they suffer much, and it takes them several years before they get settled in their new place. An olive tree, weaker, raised in dry land, will always develop with more vigor than another one stronger coming from an irrigated soil.
The young plants in nursery, says Du Breuil, should be protected from drought only through the means of hoeings practiced during the summer, and he adds that when taking them from the nurseries they will accommodate themselves Very much better to the burning soils where they will be planted than if they had been subjected to irrigation during their tender youth.
However, this practice which is recommended for the south of France and Italy where spring showers and summer storms are quite frequent and are generally sufficient to bring to those young plants the necessary elements of life, should not be adopted in an absolute manner in California, where sometimes there is no rain, or none of much account, from April until October or November. This is why, in the absence of rains, a few waterings distanced according to the season will perhaps be necessary to insure their start and promote their best development.
The little herbaceous cuttings raised in boxes, where there is not more than from four to five inches in depth of soil, should be occasionally watered, and just enough not to allow this thin bed to dry out, but it would prove a mistake to water them too abundantly.
For it might be said that the olive tree dreads too much water, or as much at least as will prove beneficial to other plants. While the vine cutting will grow luxuriantly with the help of repeated waterings, the olive cutting will suffer when similarly treated, and will certainly die out if its languid appearance, previous to its start being taken as indicating a need of water, it is too much soaked with it. Thus caution should be exercised in the waterings to be given to the young plants raised in nursery, but the ground should be loosened at their base as often as possible.
Frequent hoeing, while destroying the weeds, maintain always around the plants a moisture which is propitious to their growth, otherwise the ground would dry and form a kind of crust during the burning heat of the summer, especially in California, where rains are almost unknown from June to October; it would hardly be penetrated by the air and would not receive the beneficial effects of the atmospheric influences.
The most favorable season for transplanting to permanent sites those small one-year old rooted cuttings is dependent on the location selected. If the soil is light and dry, it should be done before winter; if heavy and damp, in the spring.
It is a fact generally admitted that in dry soils it is important to make plantations of rooted cuttings in autumn, their start being then much more assured; while in the wet lands, where the roots could not spread easily, it is preferable to wait until spring; for, the facility with which those soils retain the water maintains a permanent state of humidity which produces rot in the roots and brings about symptons of decay soon followed by he death of the plant. When on the contrary the planting is done in the fall in a dry and light soil, the water which it receives during the winter rains percolates freely to the lower stratum, numerous ramifications of the roots, which under our exceptional climate know nearly no repose, absorb it through all their pores and young trees develop with an astonishing vigor, gaining during a mild winter, as is so in the case here, from two to three months on the vegetation of the principal olive bearing zones of Europe, where winters are generally longer and more severe than those experienced in this perpetual-spring climate of California.
To resume what has been already said in this chapter, I am decidedly in favor of the propagation of the olive tree in our climate by means of small cuttings, freshly cut at those periods of the year when the tree experiences a comparative repose, coming directly or originally from grafted trees, and raised in boxes or nurseries. When one season old these little rooted plants are ready to be transferred to permanent sites; there they will make a growth of from two to three feet a year; they will develop more rapidly than vine cuttings of similar age, as I have had frequent occasion to verify, and they will begin to bear some fruit in their fourth year, as has been asserted repeatedly by Mr. Elwood Cooper of Santa Barbara; Mr. Frank A. Kimbal, of San Diego; Mr. W. G. Klee, of the State University; Mr. W. A. Hayne, Jr., of Santa Barbara; Mr. L. A. Gould, of Auburn; Mr. Isaac Lea, of Florin; Captain Guy E. Grosse, of Santa Rosa; Mr. H. W. Crabb, of Oakville; Mr. A. B. Ware and Colonel Geo. F. Hooper, of Sonoma, etc.
In reference to this I will quote the following extracts:
From Mr. Elwood Cooper's Treatise on the olive: "Trees growing from cuttings will produce fruit the fourth year, and sometimes, under the most favorable circumstances, will give a few berries the third year. My oldest orchard was planted February 21st, 1872. At four years I gathered from some of the trees over two gallons of berries. In 1878 over thirty gallons each off a few of the best trees, the orchard then being only six years old.
"The newness and richness of our soil will probably give, the first fifty years, double the best results given in the oil countries of Europe."
From the San Francisco Evening Bulletin, May 3, 1887: "It is often stated that the olive tree will not bear until its seventh or eighth year. Capt. Guy E. Grosse, of Santa Rosa, thinks that on his mountain ranch may be found proof satisfactory that such is not the case. Out of his 500 olive trees, planted four years ago, 461 are in full bloom and promise a good yield. Further and successful refutation of the statement concerning the maturity age of the olive may be found in this city. On A. B. Ware's premises is an olive tree four and one half years old which bore a good crop last year.—Sonoma Democrat."
Similar affirmations have been made by so many other parties who have engaged in olive culture in California that it seems unreasonable to doubt it any more. It leads us to the belief that those who have olive trees here bearing nothing, or but a few small berries, at an advanced age, must have reproduced them from cuttings taken from trees raised from the seed and which were never grafted.
That the fact of the early bearing mentioned above is the result solely of the mode of propagation by cuttings, of our exceptional climate, or of our virgin soil, or the result of these three elements combined, matters but little. It is a fact, and the proofs are superabundant.
But if, on the contrary, the olive tree is raised from the seed it has to remain many years in the nursery until it develops sufficient strength to admit of successful grafting; and when transplanting it, the tap-root as well as part of the top having to be taken off, the roots also suffering from exposure to the air which it will be impossible then to avoid, all of this will combine to inflict a long and severe injury upon its whole system, which will delay considerably its bearing period.
There will certainly be a difference of fully five years in the time of its production according to the one of those two modes of reproduction that will have been adopted.