This question came to the Master Gardener booth at the Waxahachie Farmers Market.
My neighbor has been telling me I should grow and use Holy Basil. What is it and how do I grow it?~Cynthia
Holy Basil (Ocimum tenuiflorum/sanctum) is a distant relative of sweet basil and Thai basil. It is commonly used as a medicinal herb in India; It also makes a wonderful tea. Holy basil is sometimes distinguished from the other basils by being called Tulsi.
Holy basil is native to tropical and subtropical Asia. It’s an aromatic plant in the mint family, Lamiaceae. It is spicier than other basils and quicker to go to seed, but still usable when covered with purple flowers. Plants will grow to 12-24 inches tall and wide, with hairy stems and simple, green leaves that are strongly scented. Leaves are ovate, up to almost 2 inches long, usually slightly toothed. The flowers are purplish in close elongated whorls. It is a perennial in it’s homeland, but acts as an annual here in Texas.
To grow, direct seed when soil warms up in late spring or transplant after danger of frost in well-drained moderately rich soil. I was able to find seeds on Amazon. The seeds are VERY tiny. Young seedlings will damp off if heavily watered during cool cloudy weather. Thin to 8–12”, pinch off the tops of mature plants to induce branching and increase total yield. Harvest before plants blossom. Holy Basil is heat loving and more tolerant of cold than most basils but absolutely intolerant of frost and damaged by temperatures in the 30s.
As far as the medicinal properties of Holy Basil go, although they sound wonderful, they are mostly unsubstantiated. However, from personal experience, I can tell you the tea is delicious.