Common Name: Sweet Basil

General Information

Ocimum basilicum is an erect, much-branched, perennial, aromatic plant growing 20 - 80cm tall. The plant is often grown as an annual, especially in cooler climates.
A very commonly used herb with a range of culinary and medicinal applications. The plant also yields an essential oil and has insect repellent properties. It is often grown in gardens and commercially.
There are reports that the plant can become a weed in cultivated fields[].

Known Hazards

None known

Botanical References

,

Range

Tropical Asia - China, Indian subcontinent, Myanmar, Thailand, Cambodia, Laos, Vietnam, Malaysia, Indonesia, Philippines, New Guinea.

Habitat

Long cultivated, its original habitat is obscure[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	0.45 m
Pollinators	Bees
Cultivation Status	Cultivated, Ornamental

Cultivation Details

Basil is a plant of the tropics, though it can also be grown in the subtropics and succeeds outdoors when grown as an annual in the warm temperate zone. In the tropics, it succeeds up to an elevation of 1,000 metres[]. It grows best in areas where annual daytime temperatures are within the range 18 - 27°c, but can tolerate 7 - 36°c[]. It is intolerant of frosts. It prefers a mean annual rainfall in the range 1,000 - 1,600mm, but tolerates 600 - 4,300mm[].
Prefers a sunny, sheltered position[]. Prefers a rich light well-drained to dry soil[, , ]. Prefers a pH in the range 6 - 7, tolerating 4.3 - 8.2[].
The plant takes 70 - 110 days from germination to first harvest, and can thereafter be cut up to three more times at 60 day intervals, the harvesting taking place just before the crop starts flowering[].
Average yield is 1.2 - 1.5 tonnes per hectare of dry, cleaned drug[].
There are a number of different constituents that make up the essential oil in basil, and the proportions of these vary considerably between plants growing in different regions of the world[]. From this variety many named varieties with differing flavour characteristics have been developed[, ].

Edible Uses

Leaves and flowers - raw or cooked[, , ]. Used as a flavouring or as a spinach[, ], they are used especially with tomato dishes, pasta sauces, beans, peppers and aubergines[]. The leaves are normally used fresh but can also be dried for winter use[]. A very pleasant addition to salads[], the leaves have a delightful scent of cloves[]. Use the leaves sparingly in cooking because the heat concentrates the flavour[].
A refreshing tea is made from the leaves[].

The seed can be eaten on its own or added to bread dough as a flavouring[]. When soaked in water it becomes mucilaginous and can be made into a refreshing beverage called 'sherbet tokhum' in the Mediterranean[].

An essential oil obtained from the plant is used as a food flavouring in mustards, sauces, vinegars etc[, , ]

Medicinal

Sweet basil has been used for thousands of years as a culinary and medicinal herb. It acts principally on the digestive and nervous systems, easing flatulence, stomach cramps, colic and indigestion[].

The leaves and flowering tops are antispasmodic, aromatic, carminative, digestive, galactagogue, stomachic and tonic[, , , , ]. They are taken internally in the treatment of feverish illnesses (especially colds and influenza), poor digestion, nausea, abdominal cramps, gastro-enteritis, migraine, insomnia, depression and exhaustion[]. Externally, they are used to treat acne, loss of smell, insect stings, snake bites and skin infections[]. The leaves can be harvested throughout the growing season and are used fresh or dried[].

The mucilaginous seed is given in infusion in the treatment of gonorrhoea, dysentery and chronic diarrhoea[]. It is said to remove film and opacity from the eyes[].

The root is used in the treatment of bowel complaints in children[].

Extracts from the plant are bactericidal and are also effective against internal parasites[, ].

The essential oil is used in aromatherapy. Its keyword is 'Clearing'[].

Agroforestry Uses:

Sweet basil is a good companion plant for tomatoes but it grows badly with rue and sage[, , , ]. When grown near raspberries it can retard their fruiting[].
A very good companion plant to grow in the house or greenhouse, its aromatic foliage helping to reduce problems caused by insect pests[].

Other Uses

An essential oil obtained from the whole plant is used as a food flavouring and in perfumery, dental applications etc[, , , , , ]. An average yield of 1.5% essential oil is obtained from the flowering tops[]. When applied to the skin it makes a good mosquito repellent[].

The growing or dried plant is an effective insect repellent. It is a good plant to grow in the home, where it repels flies, or in the greenhouse where it can keep all manner of insect pests away from nearby plants[, , ]. It has been used in the past as a strewing herb[].

Propagation

Seed - sow mid to late spring in a greenhouse and only just cover the seed. Germination is usually free and quick, prick out the seedlings into individual pots when they are large enough to handle. If growing basil outdoors, plant out after the last expected frosts.