Ocimum americanum aka Sweet Basil

Ocimum americanum is an aromatic herb in the mint family, Lamiaceae. Common names include hairy basil and hoary basil. Its native range covers the tropical and subtropical Old World. It grows across tropical Africa and much of southern Asia. Its range also reaches Indonesia, the Philippines, and New Guinea. People gather wild plants and grow it as a crop. It provides leaves for food and seeds for drinks.

This upright plant has a variable life cycle. Kew lists it as an annual or subshrub. Useful Tropical Plants describes a perennial, often grown as an annual. This annual use is frequent in cooler climates. That source gives a usual height of 0.7–1 foot [0.2–0.3 metres]. Its separate height entry gives 1.6 feet [0.5 metres]. Some plants reach 3.3 feet [1 metre]. The leaves have a scent and serve as a food flavouring. Plants may start flowering eight to twelve weeks after sowing. Seeds mature after fourteen to twenty weeks.

Wild plants grow beside roads, in fields, and in teak forests. They also occupy open waste ground with sun and wind shelter. Most records come from lowland sites. In gardens, the plant prefers full sun and rich, light soil. The soil should drain well and may be dry. Its preferred soil pH is 6–7, though it tolerates 5–8. Best growth occurs with daytime temperatures of 22–30°C. The reported tolerance range is 10–35°C. Seed can go straight into its growing site. Germination takes about one to two weeks. Harvest can begin two to three months after sowing.

Young leaves can be eaten raw or cooked. Cooks steam them as a side dish with rice. They also add them to salads, sauces, and soups. Seeds swell and form a gel when soaked in water. In Java, this preparation is called indring. Coconut milk and sugar turn it into a sweet drink. The plant also yields an essential oil for soaps and cosmetics. Reported traditional uses include leaf paste for skin complaints. People also apply it to wounds and burns that heal poorly.

Useful Tropical Plants reports no known hazards for this species. That statement does not establish safety for every use. The plant can become a serious farm weed in western Africa. This weed risk matters when choosing where to grow it.