You can’t believe how sweet this plant is! Stevia leaves are 10 times sweeter than sugar, but have almost no calories and lack the aftertaste of artificial sweeteners. Refined Stevia has been available for years at health stores as an all-natural alternative to sugar. Now is your chance to grow the plant at home. Plants grow to 3′ tall and are only hardy to zone 10. In the winter, bring it indoors and use it as a house plant.