A South American perennial shrub (Stevia rebaudiana), stevia is an herb with small, moderately broad green leaves and reaches approximately 2 feet high at maturity. Stevia leaves are considered to be anywhere between 10 to 300 times sweeter than traditional white sugar, yet they contain neither calories nor carbohydrates.
Though stevia only recently gained publicity in the U.S., it has been used as a sweetener for thousands of years by native Central and South American peoples. For diabetics and dieters alike, stevia is a good alternative to sugar. Stevia also has a mild, bitter, licorice-flavored aftertaste.
While the U.S. did place a trade embargo on stevia in the 1990s because its safety had not been thoroughly proven, it was verified by the FDA (in 2008) that stevia doesn’t present any long-term dangers. According to Andrew Weil, MD, the director of the Program in Integrative Medicine at the University of Arizona, stevia has endured centuries of human use without any known side effects.
To be used in baking and cooking, stevia leaves must be dried out and ground into a granulated form: a fine white powder. However, you can use stevia leaves as sweeteners for hot drinks by dropping the leaves directly into the beverage. Using stevia leaves in cold drinks doesn’t have the same effect.
Stevia is not as easy to grow as most culinary herbs, but it has been successfully grown in climates ranging from southern Canada to the American South. Stevia is hardy in USDA Plant Hardiness Zones 11 and up, and does best in semi-humid locations with acidic, well-draining soil. Space plantings 8 to 10 inches apart in a location where they will receive full sun. Stevia grows best when soil pH ranges from 6.7 to 7.2.
One can often find stevia in your local nursery’s herb section. The majority of stevia plants are sold as cuttings.
This herb grows best in cooler summer weather with strong sunlight, but generally fairs poorly in high temperatures. Stevia grows well in containers. Like oregano and basil, stevia grows well in pots when 1 to 2 plants to a pot. When blooming, stevia plants display crisp white flowers. Stevia typically blooms in early to mid-Autumn.
Photo: (cc) FarOutFlora/flickr
While these plants have been known to overwinter in climates as low as Zone 8, if planting stevia in a colder climate, you run the risk of losing plants to frost. The solution is to grow stevia as an annual, or overwinter the plant indoors.
Be careful when weeding, as the plant’s branches are fairly brittle. Stevia doesn’t have any known diseases or pests. But it would be smart to defend against pests and diseases that plague similar culinary herbs.
At the end of September or beginning of October, harvest the entire plant once flower buds have appeared but before they’ve opened. Ideally, harvest in the morning when the plant is at its highest sugar content. Also, be sure to harvest before many flowers (4-5 buds) have opened. If most of the flowers have blossomed, they will leave behind a bitter aftertaste throughout the entire plant.
Stevia also has several health benefits. Not only does stevia possess hypoglycemic effects when ingested, but it also can help improve insulin production: a benefit that may be intriguing to diabetics. Stevia is a natural antioxidant, helping your body fight against free radicals (molecules that can damage cells, lead to heart disease and cancer, as well as other illnesses). Stevia can help with hypertension, or high blood pressure, and also inhibits the growth of bacteria that can create dental cavities.
Photo: (cc) Gabriela Ruellan/flickr
If you're interested in growing stevia, here are some seed resources: