Stevia is a sweetener and sugar substitute extracted from the leaves of the plant species Stevia rebaudiana.The active compounds of stevia are steviol glycosides (mainly stevioside and rebaudioside), which have up to 150 times the sweetness of sugar, are heat-stable, pH-stable, and not fermentable.These steviosides have a negligible effect on blood glucose, which makes stevia attractive to people on carbohydrate-controlled diets. Stevia’s taste has a slower onset and longer duration than that of sugar, and some of its extracts may have a bitter or licorice-like aftertaste at high concentrations.The legal status of stevia extracts as food additives and supplements varies from country to country. In the United States, stevia was banned in 1991 after early studies found that it might be carcinogenic; after additional studies, the FDA approved some specific glycoside extracts for use as food additives in 2008. The European Union approved stevia additives in 2011, and in Japan, stevia has been widely used as a sweetener for decades.
HOW TO GROW
- While tolerant of most soil types, Stevia prefers a sandy loam or loam. Any well-drained soil that produces a good crop of vegetables should work fine.
- Stevia rebaudiana seeds are rarely available because of production problems and poor germination, so plants are generally used instead. Plants are available from several mail order sources.
- Use small containers (with drainage holes) or plastic cell packs filled with standard potting soil. Place 3 or 4 seeds on the soil surface in each container and cover with a thin layer (about 1/8 inch) of horticultural vermiculite. Water from below as needed by pouring water into the tray. Seedlings should emerge in 1 to 2 weeks. Thin to one plant per container. Extra seedlings may be transplanted to empty containers.
- Irrigate once or twice a week, whenever rain fails to water the plants. Sandy soils require more frequent irrigation. Trickle irrigation is ideal, ensuring consistent moisture levels without wetting leaves.
- Plants should be harvested before the first frost or as soon as blossoming begins, whichever comes first. Cut entire plants just above ground level. When growing Stevia as a perennial or for early harvests, clip the plants 6 inches from the ground so they will survive and re-grow (Shock, 1982). Harvest in the morning, after dew has evaporated.
- 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 culinaryherbs.
- Studies have shown that taking stevioside (one of stevia’s sweet compounds) as a supplement can reduce blood pressure.
- Another study compared sucrose (regular sugar), aspartame and stevia. It found that stevia lowered both blood sugar and insulin levels after a meal, compared to the other two sweeteners