If growing your own food sweetener is appealing, cultivating stevia might be a worthwhile project. This leafy plant, treated as an annual in most parts of the United States, is a tender perennial when grown in sub-tropical regions. Long used by South American natives to sweeten their beverages, stevia is many times sweeter than sugar.
Fill a flat with sterile seed-starting medium and barely cover the seeds with a thin sprinkling of medium.
Moisten the medium until damp but not soggy.
Place the plastic dome on the flat. Move the flat where the temperature is approximately 75 degrees F. Check for sprouting every day after one week.
Remove the plastic dome as soon as the seedlings begin to sprout. Place the flat where the seedlings will receive direct sunlight, such as a south-facing window.
Prepare garden soil by incorporating sand or loam, and work it thoroughly to a depth of at least 10 inches. Compost and other types of organic matter, such as manure, are beneficial.
Sprinkle stevia seeds in a row on top of the soil 2 or 3 inches apart. The tiny seeds will settle into crevices in the soil and no further covering is necessary. Sprinkle lightly with water. After germination thin the plants to 10 inches apart.
Water stevia plants from the bottom by letting a hose trickle or by placing a soaker hose near the base of the plants. Spraying the plants with water increases the risk of fungus.
Mulch around the stevia plants during hot weather with a 2- to 3-inch layer of compost, dry leaves, grass clipping or straw to retain moisture in the soil. Stevia roots are shallow and may suffer if the soil temperatures become hot.
Fertilize stevia with a commercial, low-nitrogen fertilizer such as a 10-10-12 formulation. Apply the fertilizer one month after the seeds sprout and again in one more month. Follow the label's instructions for dosage.