Ocimum tenuiflorum Seeds | Holy Basil
LATIN NAME: Ocimum tenuiflorum
COMMON NAME: Holy Basil
Plant Profile
Ocimum tenuiflorum is the tulsi of Indian courtyards, grown in a pot by the door and treated as a household member rather than as a crop. It is a small, woody-based annual or short-lived perennial, thirty to sixty centimetres high, with hairy stems, opposite leaves and spikes of small purple flowers. The leaf is the point: it is aromatic, slightly bitter and peppery, and it is eaten fresh.
Several forms are grown. Rama tulsi has green leaves and a strong clove scent, Krishna tulsi has purple leaves and a sharper taste, and Vana tulsi is a different species, Ocimum gratissimum, with a perfume closer to lemon basil. The plant is native to the dry plains of the Indian subcontinent and is grown throughout the tropics, both as a medicine and as a sacred plant.
Science & Biotechnology
The leaf oil is dominated by eugenol, with smaller amounts of methyl eugenol, caryophyllene and ursolic acid. Eugenol is the same compound that gives clove its numbing quality, and it is why the leaf is chewed for toothache and for mouth ulcers. Ursolic acid has been studied for anti-inflammatory activity, and the leaf also contains flavonoids and a small amount of essential oil rich in antioxidants.
Tulsi is often described as an adaptogen, a claim that rests mostly on animal studies and on small human trials with inconsistent products. The plant does lower blood sugar in some studies and does thin the blood slightly, which matters for people on warfarin or on diabetes medication. It is a useful herb, but the marketing has run well ahead of the evidence.
Uses & Benefits
The leaf is eaten fresh, made into a tea with ginger and honey, and used as a flavouring in chutneys and in salads. The seed, soaked in water, becomes mucilaginous and is used as a cooling drink in summer, and the dried leaf is used as a snuff for colds.
In Ayurveda the plant is used for coughs, for fever and for skin complaints, and it is applied as a paste to insect bites. It is also planted around houses as a mosquito repellent, a use that has some support from studies of the leaf oil, though a potted plant does not protect a room.
Growing from Seed
Seed is small and should be surface-sown. Sow it at 20 to 25 degrees in spring, press it into the compost and keep it moist; germination is in one to two weeks. The seedling is fast and can be pinched to make a bushy plant.
The plant wants full sun, warmth and a well-drained soil, and it is tender below about five degrees, so it is grown as an annual in a cool climate. Water it regularly but do not let it stand in water. Pinch out the flowers to keep the leaves tender, and take cuttings in late summer if you want to keep a particular plant through winter.
Our Take
A small, generous herb for a pot by the door, best used fresh and best not treated as a cure for anything.
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