A perennial herb that grows hardy to 10 degrees F, and in zones 9+, may also be grown as an annual. Its dried leaf is used for sweetening drinks. Does best if sown just under the surface, tamped well, kept evenly moist and in direct sun. Germinates in 1 to 2 weeks. Protect from slugs, which like the sweetness. Grows well in pots or rich garden soil, in full sun to part shade, humidity, and plenty of water.
The Guarani Indians had known for centuries about the unique advantages of kaa he-he (a native term which translates as “sweet herb”) — long before the invaders from the Old World were lured by the treasures of the New. These native people knew the leaves of the wild stevia shrub (a perennial indigenous to the Amambay Mountain region) to have a sweetening power unlike anything else; they commonly used the leaves to enhance the taste of bitter mate (a tea-like beverage) and medicinal potions, or simply chewed them for their sweet taste. The widespread native use of stevia was chronicled by the Spaniards in historical documents preserved in the Paraguayan National Archives in Asuncion. Historians noted that indigenous peoples had been sweetening herbal teas with stevia leaves “since ancient times.” In due course, it was introduced to settlers. By the 1800s, daily stevia consumption had become well entrenched throughout the region — not just in Paraguay, but also in neighboring Brazil and Argentina.
Like the discovery of America itself, however, credit for stevia’s “discovery” goes to an Italian. In this case, the explorer was a botanist whose initial unfamiliarity with the region (along with his difficulty in locating the herb) caused him to believe that he had stumbled onto a “little-known” plant.