Olive

Family

Oleaceae

Habit

Tree

Height

9 m

Spread

8 m

Growth

slow

Lifespan

2000 years

First yield

after 8 years

Full yield

after 60–100 years

Yield per plant

up to 200 kg a year

Yield in cultivation

up to 5 t/ha

Energy yield

150 kcal per m² a year

Hardiness

zone 8–11

Shade tolerance

full sun

Soil

Sand, Silt, Loam

Soil moisture

very dry – very moist

pH

5.5 – 8

Synonyms

Olivenbaum

Times apply to the northern hemisphere in a temperate climate and shift with altitude and cultivar.

Edible: Olives are commonly used in the Mediterranean region as a stimulant and flavoring agent in cuisine. The fruits are typically preserved in water, brine, oil, salt, or lye, or can be dried and consumed without curing, known as "fachouilles." Cured olives are enjoyed as a relish, stuffed with pimento or almonds, or incorporated into various dishes like bread, soups, and salads. "Olives schiacciate" are green olives that are crushed, preserved in oil, and used in salads. Each fruit contains 20-50 µg of vitamin D per 100 g and can reach up to 4 cm in length. The seed is rich in edible, non-drying oil used in salads and cooking as a condiment due to its strong flavor. Olive oil comes in different grades, with the highest quality known as "extra virgin," obtained by cold-pressing the seeds without heat or chemical solvents. Monounsaturated olive oil is believed to lower the risk of cardiovascular disease with regular consumption. The seed also contains protein, a unique characteristic among seeds. Additionally, an edible manna is derived from the olive tree.

Medicinal: The plant has diuretic properties. There is no evidence of a laxative effect, but it contains an alkaloid with mydriatic effects. The seeds, known for their pungent taste and highly toxic potency, are utilized in Tibetan medicine. They offer analgesic, anthelmintic, antibacterial, anti-inflammatory, and antipyretic properties. Regular consumption boosts physical vitality and aids in treating infectious diseases, toothaches, worm-induced intestinal pain, and impotence. A seed decoction is employed to address fever.

Other uses: The oil from the seeds serves various purposes like soap production, illumination, and lubrication. It is beneficial as a hair treatment and for dandruff. Dyes in chestnut-brown and purple hues come from fresh, ripe fruits, with blue and black dyes from the skins. Yellow-green dye is obtained from the leaves. These plants help secure arid, dusty inclines. The wood, hard and heavy with a lovely grain, is easily polished and faintly fragrant. It is favored in woodturning, joinery, and esteemed by wood craftsmen.

Site: Free-draining and rather lean — waterlogging kills it more reliably than frost does. In Central Europe the winter alone decides: at about -12 °C it is only marginally hardy and belongs in a container, in the warmest sheltered spot, ideally against a south-facing wall. Planted out it succeeds only in mild vine-growing areas. Its powers of recovery are reassuring: from the woody burls at the root collar it reshoots after frost or cutting damage — an apparently dead tree is rarely lost. Care: In summer water too little rather than too much. Feed only from spring until about July; later feeding forces soft wood that survives the winter poorly. Overwinter bright at 5 to 10 °C, never warm indoors — there it drops its leaves and exhausts itself; water only enough to keep the rootball from drying out. In winter quarters scale and mealybugs are the commonest problem, so check the undersides of leaves regularly. Thin in spring, since it flowers on the previous year's wood.

Cultivars are not raised from seed, as seedlings do not come true and bear only after many years. Vegetative propagation is the norm: cuttings of semi-ripe shoots root given even moisture and bottom heat and yield genetically identical plants; commercial growing also grafts onto seedling rootstocks. A peculiarity of the species are the woody burls at the root collar, from which new plants can likewise be raised — the same capacity lets old trees reshoot from the stump after frost or fire. Wild plants are dispersed by birds that eat the drupes. Sowing succeeds only after the flesh has been removed completely and the seed stratified at length.

The olive flowers in inconspicuous, fragrant panicles and is pollinated primarily by wind; insect pollination is not required for fruit to set. Bees and wild bees do visit the flowers, but mainly for pollen — as a nectar source the olive is of little value. For the insect fauna of Central Europe it hardly matters in any case, since it is usually grown in a container here and rarely reaches the age and flowering mass it achieves in its native range. There, by contrast, old olive groves rank among the most valuable cultural habitats of all: the gnarled, cavity-rich trunks shelter bats, little owls and hoopoes along with a rich deadwood fauna.

Special features: Drought-resistant, tolerates salty air; stabilizes dry slopes; Cultivation: Trees/ha: traditional 30-200, intensive 250-600, super-intensive 1500-3000; There are self-fertile fruit/oil varieties; 100kg~15L oil; Old trees produce >200kg olives, but only every 6th/7th season; Flowering requires 2 months below 10°C;

Mediterranean region and western Asia. The wild form Olea europaea subsp. sylvestris, the oleaster, is native throughout the Mediterranean — from the Iberian peninsula to the eastern Mediterranean coast. Genetic evidence points to the northern Levant as the primary centre of domestication; from there the cultivated olive spread across the whole Mediterranean. Today it is additionally grown in California, South America, South Africa and Australia. There is no natural occurrence in Central Europe; the northernmost planting in Europe has stood at Stommeln near Cologne since 2008, with over 170 trees.

The olive belongs to the evergreen sclerophyllous vegetation of the Mediterranean and is a character species of the Oleo-Ceratonion — the warmest tier of the maquis, tied to hot, summer-dry coastal country. There it grows on dry, stony and shallow soils, in open woodland and scrub, mostly near the coast up to about 200 m. Its optimum lies at annual mean temperatures of 15 to 20 °C and annual rainfall of 500 to 700 mm. Summer drought is part of its habitat and is buffered by deep roots and hard, small-surfaced foliage. Winter cold alone is limiting: severe frosts endanger both crop and stands.