Stevia rebaudiana is a fascinating plant, native to the higher altitudes of Paraguay and Brazil in South America. Stevia is the genus, meaning a
broad classification of plants. Rebaudiana is the species name. Only this species, out of the many found in the Americas, contains the high concentration of sweet glycosides making this “sweet leaf” such a useful and amazing herb. The dried leaf, in fact, is 10-15 times sweeter than cane sugar! Powdered stevia leaf, known as green stevia powder, may be found for sale at natural food stores or online while waiting for your first harvest. See "Choosing Stevia Products" for more about the different forms of stevia for table use.
Not a particularly showy plant, stevia’s sweet taste is its most notable feature. It is a non-woody herb with somewhat stiff and brittle stems. Stevia leaves are small and narrow, notched on the end. The leaves are much sweeter than stems. Plants reach about 2 feet in height. Stevia is a tender perennial herb, which means it survives winters and keeps growing, but only where winters are mild. The roots may survive some winters as far north as USDA hardiness zone 8.
Fortunately, stevia may be grown as an annual outdoors. The long summer days in colder climates are actually an advantage for growing stevia. Plants grown at higher latitudes with more daylight will have more leaves and a higher percentage of sweet glycosides.
Find more about growing stevia in Jeffrey's books, Growing and Using Stevia: The Sweet Leaf from Garden to Table with 35 Recipes. or Growing Stevia for Market: Farm, Garden, and Nursery Cultivation of the Sweet Herb, Stevia rebaudiana