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Ceratonia siliqua - L.

Common Name Carob, St. john's bread
Family Fabaceae or Leguminosae
USDA hardiness 9-11
Known Hazards None known
Habitats Rocky places near the sea shore[89].
Range S. Europe.
Edibility Rating    (3 of 5)
Other Uses    (2 of 5)
Weed Potential No
Medicinal Rating    (2 of 5)
Care (info)
Frost Hardy Well drained soil Moist Soil Full sun
Ceratonia siliqua Carob, St. john

Ceratonia siliqua Carob, St. john


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Bloom Color: Green. Form: Rounded, Vase.

Physical Characteristics

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Ceratonia siliqua is an evergreen Tree growing to 15 m (49ft 3in) at a medium rate.
See above for USDA hardiness. It is hardy to UK zone 8 and is frost tender. It is in leaf all year, in flower from August to October. The species is dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required). and is pollinated by wasps and flies.
It can fix Nitrogen.
Suitable for: light (sandy) and medium (loamy) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very alkaline soils.
It cannot grow in the shade. It prefers dry or moist soil and can tolerate drought. The plant can tolerates strong winds but not maritime exposure.

UK Hardiness Map US Hardiness Map


Plant Habitats

Woodland Garden Canopy; Secondary; South Wall. By. West Wall. By.

Edible Uses

Edible Parts: Seed  Seedpod
Edible Uses: Chocolate  Coffee  Egg  Gum

Seedpods - raw or ground into a powder[1, 7, 74, 89, 177]. The seedpods are filled with a saccharine pulp and can be eaten both green or dried[2]. They are very sweet but fibrous[183], the pulp can be used as a chocolate substitute in cakes, drinks etc[183]. It is rich in sugars and protein[183]. The pods contain about 55% sugars, 10% protein[100] and 6% fat[74]. Seed - rich in protein. A flour is made from them which is 60% protein, it is free from sugar and starch and is suitable for baking[64, 171]. It can be used as a chocolate substitute[148]. An edible gum is extracted from the seed, a substitute for Gum Tragacanth (see Astragalus species)[64]. A stabilizer and thickening agent[142, 183], it is also used as an egg substitute[61, 64, 142]. The roasted seed is a coffee substitute[61, 105, 183].

References   More on Edible Uses

Medicinal Uses

Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.
Antidiarrhoeal  Antiemetic  Astringent  Demulcent  Emollient  Purgative

The pulp in the seedpods of carob is very nutritious and, due to its high sugar content, sweet-tasting and mildly laxative[254]. However, the pulp in the pods is also astringent and, used in a decoction, will treat diarrhoea and gently help to cleanse and also relieve irritation within the gut[240, 254]. Whilst these appear to be contradictory effects, carob is an example of how the body responds to herbal medicines in different ways, according to how the herb is prepared and according to the specific medical problem[254]. The seedpods are also used in the treatment of coughs[240]. A flour made from the ripe seedpods is demulcent and emollient[7]. It is used in the treatment of diarrhoea[7]. The seed husks are astringent and purgative[240]. The bark is strongly astringent[254]. A decoction is used in the treatment of diarrhoea[254].

References   More on Medicinal Uses

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Other Uses

Cosmetic  Fodder  Gum  Tannin  Wood

A flour made from the seedpods is used in the cosmetic industry to make face-packs[7]. Tannin is obtained from the bark[7]. Wood - hard, lustrous. Highly valued by turners, it is also used for marquetry and walking sticks[7, 61, 89, 100].

Special Uses

Carbon Farming  Nitrogen Fixer

References   More on Other Uses

Cultivation details

Agroforestry Services: Windbreak  Fodder: Pod  Industrial Crop: Gum  Management: Standard  Minor Global Crop  Other Systems: Irreg. Intercrop  Staple Crop: Balanced carb  Staple Crop: Sugar

Landscape Uses:Aggressive surface roots possible. Requires a very sunny position in any well-drained moderately fertile soil[200]. Does well in calcareous, gravelly or rocky soils[132, 166]. Tolerates salt laden air[132]. Tolerates a pH in the range 6.2 to 8.6. The tree is very drought resistant, thriving even under arid conditions, the roots penetrating deep into the soil to find moisture[4, 64, 132, 200]. This species is not very hardy in Britain but it succeeds outdoors in favoured areas of S. Cornwall[1], tolerating temperatures down to about -5°c when in a suitable position[200]. The young growth in spring, even on mature plants, is frost-tender and so it is best to grow the plants in a position sheltered from the early morning sun[K]. The carob is frequently cultivated in warm temperate zones for its edible seed and seed pods[1]. Mature trees in a suitable environment can yield up to 400 kilos of seedpods annually[64]. There are named varieties with thicker pods[64, 183]. Seeds are unlikely to be produced in Britain since the tree is so near (if not beyond) the limits of its cultivation[K]. The seed is very uniform in size and weight, it was the original 'carat' weight of jewellers[1, 89]. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[200]. Special Features:Edible, Not North American native, Inconspicuous flowers or blooms.

Carbon Farming

  • Agroforestry Services: Windbreak  Linear plantings of trees and shrubs designed to enhance crop production, protect people and livestock and benefit soil and water conservation.
  • Fodder: Pod  Fodder plants with pods.
  • Industrial Crop: Gum  Used as thickeners and gelling agents. Non-destructively harvested gums come from tapped trees and seed.
  • Management: Standard  Plants grow to their standard height. Harvest fruit, seeds, or other products. Non-Destructive management systems.
  • Minor Global Crop  These crops are already grown or traded around the world, but on a smaller scale than the global perennial staple and industrial crops, The annual value of a minor global crop is under $1 billion US. Examples include shea, carob, Brazil nuts and fibers such as ramie and sisal.
  • Other Systems: Irreg. Intercrop  Irregular intercropping systems are trees scattered throughout cropland.
  • Staple Crop: Balanced carb  (0-15 percent protein, 0-15 percent oil, with at least one over 5 percent). The carbohydrates are from either starch or sugar. Annuals include maize, wheat, rice, and potato. Perennials include chestnuts, carob, perennial fruits, nuts, cereals, pseudocereals, woody pods, and acorns.
  • Staple Crop: Sugar  Perennial sugar crops include sugarcane and compare favorably to annuals.

References   Carbon Farming Information and Carbon Sequestration Information

Temperature Converter

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Plant Propagation

Seed - pre-soak for 24 hours in warm water prior to sowing. If the seed has not swollen then give it another soaking in warm water until it does swell up. Sow in a greenhouse in April[200]. Germination should take place within 2 months. As soon as they are large enough to handle, prick the seedlings out into individual deep pots and grow them on in a greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Give them some protection from the cold for their first few winters outdoors.

Other Names

If available other names are mentioned here

TEMPERATE ASIA: Israel, Lebanon, Syria (west), Turkey,Cyprus. EUROPE: Former Yugoslavia, Albania, Greece (incl. Crete), Italy (incl. Sardinia, Sicily), Spain (incl. Baleares), France (incl. Corsica), AFRICA: Spain, Canarias, Algeria (north), Libya (northeast), Morocco, Tunisia.

Weed Potential

Right plant wrong place. We are currently updating this section. Please note that a plant may be invasive in one area but may not in your area so it’s worth checking.

Conservation Status

IUCN Red List of Threatened Plants Status :

Related Plants
Latin NameCommon NameHabitHeightHardinessGrowthSoilShadeMoistureEdibleMedicinalOther

Growth: S = slow M = medium F = fast. Soil: L = light (sandy) M = medium H = heavy (clay). pH: A = acid N = neutral B = basic (alkaline). Shade: F = full shade S = semi-shade N = no shade. Moisture: D = dry M = Moist We = wet Wa = water.


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Readers comment

saracoglu ibrahim adnan   Sat Mar 23 16:11:14 2002

Link: prof.dr.saracoglu against low libido, asthma, and increase the active sperm level

saracoglu ibrahim   Sat Jan 15 07:17:28 2005

Link: Prof.Dr.Saracoglu

itai   Sun Dec 18 2005

when green the pods are extreamly tanin and make the whole mouth numb. it is useful in that stage to temporary relief toothaches, and is used by beduins in the middle east in that manner.

   Sat Apr 1 2006

Where can this ingredientor ceratonia sliqua be foun or sold in bulk?Thanks! Dr.Howard Davis [email protected]

shy shahall   Sun Feb 17 2008

the flowers are not hermaphrodite, there are male trees, and female trees and it doesnot fix atmospheric nitrogen. it belongs to the Leguminose family, but to the Caesalpiniaceae sub-family

Amanda Rofe   Wed Oct 15 2008

I grew this from seed obtained from Chiltern Seeds in the early 1990s. It was difficult to germinate because the seed is rock hard. I think I soaked it in hot water and then scarified it with a sharp knife. It has grown happily in Sussex and then I moved it in a pot to Kent where it has been growing in a sunny corner of my front garden. I kept it as a bush rather than let it grow as a tree. It has never flowered or produced the lovely seed pods which I am so keen to obtain. The leaves nearly always succumb to some sort of disease like black spot on roses. It is totally hardy here and has happily sat through hard frosts, snow and a few scorching hot dry periods.

pedro   Thu May 28 2009

Are you sure that these trees can fix nitrogen like the other legiuminosae? i think i have read some articles that say that the carob does not do that.

   Jul 23 2011 12:00AM

simple correction to a previous post... The carob tree can be hermafrodite but flowers are stricly male or female. it is very comon, here in Portugal, to graft carob trees in order to enhance polinization resulting in a maximized prodution (its also current to graft hermaphrodite tree branches on female trees). Careful when buying carob seeds, this tree has also a very large genetic variability, at least 30 varieties are cultivated in the mediterranean basin, usually if it aint micropropagated u cant really garanty the product.

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