Syzygium aromaticum is a dense and handsome evergreen tree that can grow around 20 metres tall. The short bole can be around 25cm in diameter.
The plant has been valued as a spice for at least 2,500 years.
It is commonly cultivated in the tropics, especially southeastern Asia but also Africa and the Americas, for its dried, unopened flowers and the essential oil derived from them.

Known Hazards

None known

Habitat

Maritime forests in deep, well-drained sandy, acid loams with a pH as low as 4.5.

Cultivation Status

Cultivated, Wild

Cultivation Details

Cloves thrive in lowland humid tropical areas where the temperature is fairly steady, growing best in an island setting at elevations below 300 metres.
Notions about the ecological requirements of the clove vary, perhaps because of an underlying dilemma: a climate with a marked dry season promotes flowering, but the tree does not cope at all well with stress.
There are two ways out of this dilemma. The first is to choose a climate with a pronounced dry season, but to limit stress by going for deep fertile soils, providing water and shade during the early years.
The other way is to choose a wet climate with a short dry season.
The best quality cloves for use as a spice are grown in the wetter climates where annual rainfall is in excess of 1,500mm and usually in the range 3,000 - 4,000mm.
Requires a light, well-drained soil, requiring some shade, especially when young.Growth can be sustained on poor and acid soils, but waterlogging is very harmful.
Requires shelter from the wind.
The clove tree is monoecious, flowers are hermaphrodite and self-pollinating. The tree matures between 8-10 years after planting.
Clove trees live for more than 100 years, the oldest tree recorded is aged 375 years in Indonesia.
Generally, it takes 20-30 years for clove to attain full bearing.

Edible Uses

Flower buds - dried and used as a spice in a variety of foods such as cakes, baked apples and mincemeat.
The buds are sometimes chewed after meals.
An essential oil obtained from the plant is used as a flavouring in a wide range of foods such as bakery products, chewing gums, ice cream, sauces and candies.
Fruit pulp

Medicinal

Cloves, and the essential oil contained in them, are often used medicinally.
A spicy, warming, stimulant herb, it is strongly antiseptic, relieves pain, controls nausea and vomiting, improves digestion, protects against intestinal parasites, and causes uterine contractions.
Cloves are taken internally as a tea in the treatment of internal parasites, stomach upsets, chills and impotence.
The flower buds are chewed to freshen the breath or ease the pain of toothache.
The essential oil is applied externally in the treatment of toothache, headache, cold, arthritis and rheumatism.
It is also useful for treating ulcers, bruises, burns, bronchitis, asthma, minor infections and colic. It is sometimes used to ease nausea.
Two little-known compounds in clove oil have shown 'strong activity' against bacteria associated with plaque formation and gum disease.
Clove oil is very potent and can cause gum irritation, it is advisable to dilute it with equal amounts of vegetable oil. For infants an even milder dilution is required. Use should be avoided during pregnancy, or if with sensitive skin.
An infusion of the shoots and the unopened, dried flower buds (cloves) is used for an excitant.

Agroforestry Uses

None Recorded

Other Uses

Clove oil is extracted by water distillation and mixes well with cinnamon, cedar, lavender, rose and bergamot. Essential oil content in good quality cloves may exceed 15%. The oil is dominated by eugenol (70-85%), eugenol acetate (15%) and beta-caryophyllene (5-12%). Cloves contain about 2% of the triterpene oleanolic acid.
It is used in perfumery, as a flavouring and medicinally.
The cloves are used in potpourris and pomanders.

Propagation

Seed - the seed has a short viability of about 2 weeks so should be sown as soon as it is ripe in shady nursery beds, placing the seeds about 25mm deep in the soil.
About 70% of the seeds germinate, usually after 1 - 6 weeks.
Plant out when they are about 25cm tall.
Cuttings of terminal leafy softwood, kept in a frame at high humidity until they have rooted.