Holy basil (Ocimum tenuiflorum), called Tulasi or Tulsi (“incomparable one”) in Sanskrit, is a culinary herb with an ancient tradition rooted in ayurvedic medicine.

A native of India, holy basil is now cultivated all over the world. In warm, tropical climates, it grows as a perennial, but in Europe and North America, it is considered a half-hardy annual. Holy basil appreciates full sun but will tolerate filtered light and partial shade. Like other basils, it requires well-drained soil and should be planted in the late spring to early summer when day- and night-time temperatures are not likely to dip below 50 degrees F (10 degrees C).

Holy basil does well as a container plant and makes a lovely and unusual addition to the home herb or ornamental garden. It produces a pleasant fragrance that is said to discourage mosquitoes. For this reason, it is beloved by many as a patio plant.

There are two varieties of holy basil, the milder white, or pale green, and the more assertively flavored red. The leaves and stems of the red holy basil have a reddish purple cast. The leaves of both varieties are smaller than those of Mediterranean sweet basil and have serrated rather than smooth edges. The stems and leaves are lightly covered with little hairs.

Holy basil is sometimes referred to as “hot basil” or “pepper basil” because unlike sweet or Thai basil, which have a flavor more reminiscent of licorice, holy basil is spicy and more like cloves. Because its flavor intensifies as it cooks, it is preferred cooked over raw. In Thai cuisine, holy basil is often matched with garlic, hot chilies, and nam pla (fish sauce) to flavor stir-fries. It is not interchangeable with Western, or sweet, basil in most recipes that call for the latter.

Above and beyond its culinary uses, holy basil is considered one of the most sacred and important herbs in the Hindu and ayurvedic traditions. Holy basil, or Tulasi, is referred to in the Charaka Samhita, a fundamental text of ayurvedic medicine. It is valued for antibacterial, antifungal, and inti-inflammatory properties.

Holy basil is considered to be an adaptogenic herb, which means it is thought to help the body adapt to various forms of both physical and mental stress. There is some evidence that holy basil is effective in lowering blood sugar, so scientific studies are examining its potential as an aid in treating diabetes.

Holy basil is traditionally made into remedies for headaches, heart disease, colds, asthma and bronchitis, gastrointestinal disorders, and inflammatory illnesses. It is also used to combat certain forms of poisoning as well as malaria and dengue fever. Medicinal compounds utilize the leaves and essential oil of holy basil in several forms, including tea, powder, and fresh leaves.

Holy basil, is regarded as purifying to both the mind and body, and is considered an essential part of religious households in the Hindu tradition. Because this herb is considered to be not merely a medicinal or culinary herb but also a sacred herb, its care and maintenance is carefully attended to.