Garden Mastery Tips
Also known as sweet honey leaf, sweetleaf, sugarleaf
Stevia is unlike all the other herbs in your garden. It isn't used to flavor food or for it's medicinal values or it's scent. Its only use is as an herbal sugar substitute. This remarkable plant contains steviol glycosides, compounds that are up to 300 times sweeter than sugar but without the calories. Stevia powder can be purchased at health food stores, but you can easily grow your own, harvest and process it. In fact, the hardest thing about growing Stevia is trying to find it at your favorite plant store. Most nurseries do not carry it and lots of their employees have never heard of it.
Stevia is an herbaceous perennial shrub native to the highlands of Paraguay. The widespread use of Stevia was chronicled by the Spaniards in historical documents from South America. Historians noted that indigenous people had been sweetening herbal brews with stevia leaves since ancient times. In the early 1900's it was "rediscovered" and documented in botanical journals by an Italian botanist while exploring the forests of Paraguay. It has only recently become popular again as the newest sugar substitute. Unlike sugar, Stevia will not raise blood sugar levels and has little or no calories.
Growing Stevia from seed can be difficult because of poor germination rates, so it's best to start with new seedlings. This versatile plant can be grown in containers (great if you plan on bringing it in for the winter) or directly in well-drained, fertile soil. Stevia prefers full sun to partial shade. Consistent moisture is important, as its feeder roots tend to be quite near the surface. It's a good idea to add mulch for protection in the heat of summer. Stevia can grow 24 to 36 inches tall and 12 to 24 inches wide. It produces hairy stems covered in dark green, toothed leaves. Pinch the tips every 2 to 3 weeks to encourage side branching, resulting in a bushier plant. White tubular flowers are produced mid-summer. Though nontoxic, Stevia plants have been found to have insect-repelling tendencies, and it is relatively disease-free. The leaves are not aromatic but are sweet to the taste. Dried leaves are even sweeter. Use fresh leaves for tea or eat a few right off the plant. They taste great combined with mint leaves.
Harvesting should be done as late as possible, since cool autumn temperatures and shorter days tend to intensify the sweetness of the plants. It might be a good idea to take cuttings before harvesting for next year's crop. Cuttings need to be rooted before planting. Dip cuttings in a rooting hormone, then plant in a rooting medium for two to three weeks, giving the new root system a chance to form. Repot them and place them in the sunniest and least drafty part of your home until the following spring when they can be transplanted outdoors.
The fresh leaves can be cut and used immediately, but the sweetness greatly increases when the leaves are dried. The plant is easily dried by cutting and bundling, and then hanging it upside down in a dry, warm location. After a few days, rake the leaves from the stems with your fingers. Crushing the dried leaves releases Stevia's sweetness. This can be done by hand or in a coffee grinder or blender. Store your Stevia in airtight containers and it will keep well for years. You can also make liquid stevia extract by adding a cup of warm water to ¼ cup of fresh, finely crushed stevia leaves. This mixture should set for 24 hours and then be refrigerated.
If you can't find Stevia at your local nursery, the following links will take you to websites that you can order from:
Herb Gardening for Washington and Oregon, Lone Pine Publishing International, Auburn, WA, 2008