Culture
Winter hardy to USDA Zones 9-11. Best grown in dry to medium moisture, well-drained, sandy soils in full sun. Withstands drought, heat, and somewhat poor chalky soils.
Noteworthy Characteristics
Argania spinosa, commonly known as argan tree, is an evergreen, spiny-branched, large shrub or small tree that typically matures to 15-25’ tall with a larger spread to 25-40’ wide. Argan trees are endemic to a semi-desert, low-rainfall, forested region in southwestern Morocco which is bordered on the east by the Sahara Desert and on the north by the Atlas Mountains. The trees currently function as a buffer zone by preventing incursion of the Sahara Desert (desertification) further west into Morocco. In 1998, UNESCO designated a chunk of this argan forest area as an international Biosphere Reserve for purposes of monitoring and researching the argan tree, its socio-economic environment and its uses.
Mature trees are noted for having (a) thorny gnarled trunks, (b) small, oval green leaves (to 1 1/2” long) with rounded apices, (c) small, stalkless, 5-petaled, yellow-green flowers which bloom in April in axillary clusters and (d) plum-sized fruits (to 1 1/2” long) which have thick bitter peels and a sweet-smelling pulpy pericarp which surrounds a single hard nut usually containing one but sometimes 2 or 3 seeds. Fruit takes more than one year to ripen (June or July of the following year).
The oil pressed from the seeds has been used in Morocco since ancient times as a cooking oil in somewhat the same way as olive oil is used. Oil is rich in vitamin E. This tree was relatively unknown in North America until the end of the 20th century when the oil skyrocketed in popularity and price because of newly-discovered benefits from its use as an ingredient in human cosmetic products.
Genus name comes from the Latinized version of the local Moroccan name.
Specific epithet comes from the Latin word spinosus meaning spiny.
Problems
No serious insect or disease problems. In Morocco, goats will climb trees and stand on the branches to eat the leaves and fruits, which has the unfortunate consequence of stunting upward tree growth.
Argan forest areas in Morocco have declined considerably in size in the past 100 years (excessive deforestation combined with an inability to replant new trees). Desertification is the process in which productive land, usually in semi-arid areas, becomes non-productive desert primarily as a result of poor land management (e.g., unsustainable farming, mining, overgrazing and clear-cutting of land) plus climate changes. Efforts to reduce loss of trees is ongoing.
Uses
Interesting ornamental tree for warm winter areas.