Ceratonia siliqua seeds - Carob tree

The Carob tree is an iconic plant of Mediterranean regions with a dry, hot climate. This compact, slow-growing tree rarely exceeds 12m in height and forms a very wide, rounded crown that is easily identifiable. Its massive, often twisted trunk is covered with rough brown bark. Its glossy dark green leaves are compound, odd-pinnate (with an even number of leaflets). It flowers in autumn with clusters of small flowers of no real ornamental interest. After fertilisation, they develop into long brown pods, the carobs, all parts of which are used either for animal or human food. While its frost resistance is limited, it adapts very well to poor soils and drought, thanks to its deep root system. Sowing is its natural method of propagation.

Ceratonia siliqua, known by various common names, such as St John's bread or Fig tree of Egypt, belongs to the large family of Fabaceae (or Leguminosae), rich in nearly 23,000 species, the third most important botanical family. Besides many wild plants, it includes numerous forage species (alfalfa, clover...), food species (beans, peas, lentils...) and ornamental ones (Wisterias, Albizia, Cercis or Judas trees...).
The Carob tree, which is the only species of the genus Ceratonia, originates from the eastern Mediterranean basin and has spread throughout its entire perimeter. Rarely shrubby, it most often forms a small tree of 8 to 12m high, with an equivalent or greater width. It forms a very wide, very dense rounded crown, borne by a powerful trunk, with a rugged surface covered by very rough brown bark. Slow-growing, it develops hard wood and, while it takes about fifty years to reach its adult size, it can live up to 500 years, then producing superb specimens with a venerable silhouette, typical of Mediterranean landscapes. Today it is mainly cultivated in Sicily and Spain.
The evergreen leaves are compound, formed of 2 to 5 pairs of leathery, oval leaflets measuring 3 to 7cm long. The leaves are dark glossy green on the upper surface and reach 12 to 30cm long with a reddish rachis, of the same tone as the tips of the stems. Depending on the climatic zones, it will flower between July and November, in 15cm long clusters of small flowers devoid of petals. Reduced to a calyx, unisexual or hermaphrodite, the flowers have a colour ranging from yellow to brown, passing through red. They are not very decorative. In specimens grown from seed, which is generally the case, flowering appears after 6 to 8 years. The fruits only appear on wood at least three years old. These are large brown pods, 12 to 30cm long and 2 to 3cm wide, produced in large quantities. Cultivated orchards thus have yields of 50 to 100kg per plant. The carob consists of 90% pulp, the remaining 10% being the seeds. The pulp is recovered for animal feed, and when roasted, yields a flour used in confectionery and the food industry. The seeds provide locust bean gum, known as a natural food additive under the code E-410.

A precious tree in many southern countries, it can establish in very poor soils. Thanks to a symbiosis with specialised bacteria, its roots (common to Fabaceae) can capture and fix atmospheric nitrogen, thus compensating for the poverty of the soil. Its very powerful root system, capable of penetrating up to 20m deep, also allows it to withstand drought. Its only weakness is its hardiness, limited to about -7°C for a mature specimen, which restricts outdoor planting to the south.

The Carob tree is a botanical species that will find a place in a natural garden, where its wild appearance and adaptability will be well suited. Plant it alongside other plants of the same vein, such as Rock roses with their simple, ephemeral, yet constantly renewed flowers, whose simple charm is equal to often more fragile horticultural varieties. Pistacia lentiscus, or Mastic tree, is equally resistant to the harsh conditions of hot countries, and appealing with its fine, cut foliage and its highly decorative small red fruits.