The olive tree thrives best in the bright mediterranean climate, with its soft winters, its rainy autums and springs, its dry and warm summers.
Olive production is generally found to occur between 25° and 45° N. latitude and, as for France, only in the mediterranean departments.

Its development is limited by the cold as the olive trees hardly resist to temperatures of minus 12° to 15° C. Thus one can understand that olive growing is limited by latitude and altitude.

On the other hand, the tree will tolerate exceptional periods of drought and it won't suffer from violent winds.

It has nonetheless a liking for sheltered and sunbathen situations.

The olive tree is extremely hardy and quite indifferent to the soil, but it fears dampness.

It is most often grown on poor and dry soils, but its farming on rich soils (Californie) or by irrigation (Spain and Oranie) produces remarkable results.
In France, the varieties for pickling (table olives) are most often to be found on the following soils :

SOILS OF LIMESTONE SCREE (rendzine), most often sloping and held into place with dry stone walls.

The olive groves of Belgentier, for example, are planted on terraced rendzine terrains.

ALLUVIAL SOILS, which accumulate at the bottom of the slopes and in the dales of hard limestone regions. On these soils, the olive trees will never occupy the lower parts.

THE RED SOILS, on roll pebbled river terraces. A great number of olive groves of the Lower Rhône region are planted onto this kind of soil.

SKELETON SOILS, more precisely on sandstone, for instance in the region of Nyons.

It should be pointed out that the olive trees are very important to keep the soil into place in sloping regions.

Olive growers have always planted the olive groves onto terraces with sustaining dry stone walls.

Nowadays, the building and the maintenance of those walls is much too costly. Hence, one advocates more and more the use of level embankments 8 to 10 metres apart for the plantation of new olive groves.

This method has the advantage of retaining the rainwater and of preventing the soil from being carried away by the runoff.

The olive tree reproduces quite easily.

SEEDBEDS : The growing of olive plants in seedbeds has the advantage of producing sturdy trees. On the other hand, it is a slow procedure as the plants have to be grafted before being put into place.

For the nurseries, one should choose large stones coming from mature olives.

The stones are cleared of their pulp and put into stratification or cassias without damaging the almonds.

In august, the seeds are very thickly sown, at low depth in a running soil; the seedbed should be bathed regularly. The uneven gathering is compensated for by the density of the sowing.

As soon as the second year, one begins to take the best grown plants to be bedded. When they reach the size of a small finger, they are grafted onto the chosen variety.

They are ready to be put into place when the seedlings reach a height of about 50 cm.

CUTTINGS : The propagation by cuttings produces quick and excellent results, provided that one takes cuttings of sufficient dimensions. The method also has the advantage of reproducing the variety without grafting.

One should use stout branches, 10 cm wide, that are cut into logs of 40 to 50 cm. Each log is a cutting that is planted directly in a large hole.

The cutting is almost entirely buried, an extremity of 10 cm being left under ground level in such a way that it is at the bottom of a basin formed by the hole which has not entirely been filled up.

One can also use croisier cuttings chosen among branches of 4 to 5 cm wide and 25 to 30 cm long.

The croisier cuttings are grown in nurseries and can be put into place from the third year on.

STUMP CHIPS ("souchets" or "souquets") : Knobs taken from olive tree stumps that are used to be put into place directly or to form nurseries.

These stump chips or "souchets" can be chosen with or without suckers.

They rapidly take root, provided that they are sufficiently large, with an average of four pounds, to facilitate the nutrition of the young seedlings during the first years.

This method is very interesting for groves on flat grounds under a very dry climate.

The propagation by stump chips does not always permit to obtain the desired variety. Grafting is often called for.

GRAFTING.- The propagation of a given variety of table olives is done by grafting, except for special cases (cuttings, stump chips of the same variety).

Depending on what has to be grafted, the following techniques are being used :

For the seedlings and the sprouts coming from stocks of a different variety, one can use cleft grafting or budding.

In the case of older trees, be it the grafting of wild olive trees or of olive groves whose production one wishes to modify, it is advised to use inarching or bark grafting.

These operations are mainly done in springtime onto large skeleton branches. Inarching is recommended in France, and requires a very tight binding as well as a ring-shaped incision of the skeleton branch just above the graft.

Generally speaking, ever since the end of the 19th century, the surface put into culture with olive trees has increased in the regions benefitting from the warm mediterranean climate which befits more the olive tree. It regresses in the areas which are at the climatic periphery of its culture. The number of trees for table olives increses steadily.

PLANTATION :

The table olive groves of the mediterranean basin come almost all, Oranie excepting, from very ancient plantations, a certain number of which have been restored by shooting of stocks and over-grafting.

The lifespan of an olive tree is indeed extraordinary. The tree does not die, accidents put aside.
Notwithstanding, every year new groves are being created.

To this end, one uses plants which are planted at varying distances (8 to 15 metres) according to regions and varieties.

The terrain is rarely battered. Planting is mostly done in holes. On a rocky soil, the use of explosives is recommended.

Because of the caracteristics of the mediterranean climate, planting should be done in autumn.

If the tree is injured during trimming, one should carefully fill in the wounds.

In the first year, it is advised to irrigate the tree once or twice during the summer, if possible.

REGENERATION :

It may be necessary to rejuvenate an olive grove when badly cared for trees or trees that have suffered accidents have become unable to produce a normal crop.

It is sufficient to cut away all branches, except for the largest ones of which only a stump is left.

In grafting those stumps, one can rebuild a grove with a unique variety of table olives which will be homogeneous and capable of bearing fruit in excellent condition.

A trunk in very bad shape should be cut at the base in order to start anew with three replacing shoots.

The olive tree is very sensitive to farming care. Ploughing in autumn, right after the harvest is indispensable. Ploughing of new in spring is favourable followed by several scarifications and harrowings during the summer.

In non terraced olive groves, the best technique is to pass among the trees with a disc harrow, which is the ideal tool for olive farming, in autumn, in spring and several times during the summer months.

It is also very important to keep the foot of the trees clean and free of all secondary shoots.

Irrigation improves the rentability of the olive groves. It increases fruit caliber and prolongs the harvesting period.

• MANURE :

  Although manuring largely pays off, olive trees are still too rarely manured. Manure should be organic, on a basis of dung or cattle cake.

  When possible, a culture of green fertilizers (vetch, lupin, etc.), mowed at maturity and ploughed in, will complete the dressing of organic matter.

  For the olive trees to produce on average 15 to 20 kilos yearly, the formula of mineral manure is the following :

  Ammoniac Sulfate : 2 Kilos

  Superphosphate : 2 Kilos

  Potassium chlorate : 1 Kilo

  Organic manure should be applied every two years on a basis of 50 kilos of dung or 10 kilos of cattle cake. The quantity of ammoniac sulfate is then reduced to 1 kilo.

  These formulas have been established following a great number of farming experiments on a mediocre soil in the South of France.
  They should be modified according to the richness of the soil. Thus the harvest of irrigated olive groves will be largely increased.

   

• TRIMMING :

  In very sunny regions, shape trimming of the young trees should give the tree the shape of a semi-stemmed cup with 4 or 5 skeleton bushy-topped branches.

  Fructification trimming can be resumed to the following operations :

  a) Pruning to balance the tree.

  b) Cutting away of parasitical branches.

  c) Shortening of boughs that have born fruit to bring about the development of new sprouts that will bear next year's crop.

  Large trimming wounds are to be avoided.

The green olives are picked before maturity. Picking is done by hand, with the utmost care. The olives are put into wicker baskets or into cases and delivered to confectioners or to specialized cooperatives.

The producers don't sort the fruits mechanically, but they harvest several times so as to deliver olives of a homogeneous size.

The black olives are picked at full maturity. The produces sort the fruits summarily and sell the larger ones to the confectioners, the others being used for the production of oil.