The Sweet Herb of Paraguay: Growing Stevia At Home

Have you heard of the natural sweetener called stevia, yet? If not, you will soon! In March of 2013, the US FDA officially approved stevia extracts for the beverage industry, and there are already plans to release new Coke and Sprite products containing stevia in countries around the world. Currently, Europe is leading the world in the stevia market, producing over 40% of the new stevia-containing products worldwide. So stevia use is on the rise, and the trend promises to continue as consumers search for natural substitutes for processed sugar, corn syrup and harmful artificial sweeteners.

The stevia plant is a gift from nature. The leaves are 30-times sweeter than sugar, with no calories… and it is actually good for your teeth! Stevia contains natural anti-plaque and anti-bacterial agents, and one of the first commercial products to contain stevia was Rembrandt toothpaste. Of course, the sweet leaves have always been used to sweeten bitter foods and medicines, and stevia extracts are a great alternative to artificial sweeteners. Unlike many artificial sweeteners, stevia extracts are not easily broken down by acids. Stevia can be added to fruit juice vinegars to make them into ice cream toppings. Stevia is also stable at high temperatures. So it can be used in baking temperatures of up to 450° F without breaking down. Artificial sweeteners, on the other hand, will produce toxic byproducts at such temperatures. Stevia also has many health benefits, such as helping to stabilize blood sugar levels, and it has been used in native South American countries as a diabetes treatment for many years.

Unfortunately, the more processing the plant leaves go through to isolate the pure “sweet” molecules, the fewer the health benefits. So a whole-leaf product is by far the best for those seeking the full range of benefits of stevia. So why not do what I did, grow your own at home? I’ve been growing stevia in my basement in Michigan for many years, and it thrives. Amazingly, NASA tried to grow stevia as a sugar substitute for their Mission to Mars project, but it failed. So apparently you don’t have to be a rocket scientist to grow stevia; you just have to know a couple of things about the stevia plant!

The first thing I learned when growing stevia in hydroponics is that it doesn’t like a lot of nitrate-nitrogen. Stevia is native to the Amambay Mountain Range on the eastern border of Paraguay. It has a shallow root system, and since nitrates quickly wash away with soil runoff from the slopes, the plant adapted to low-nitrate conditions. When I grew stevia in an ebb-and-flow hydroponic system together with my basil and other herbs, the stevia showed signs of fertilizer burn. The edges of the leaves started to brown, even at low to medium EC’s, but the rest of my herbs looked fine. So I had to make a compromise and lower the EC in the herb garden. The next time I grew stevia, I put it into its own mini-hydroponic system. I used a bloom formula instead of a nitrate-rich grow formula, and I kept the EC at about 1.0-1.2. As the plants matured, I switched to a boost formula with no nitrate-nitrogen, and the plants grew three times larger than what the seed pack described! The sweetness of the leaves was very intense, too.

The next thing you need to know about stevia is that it is a short-day plant. In other words, as soon as the plants receive 12 hours of light and 12 hours of darkness, it goes to flower. The sweetness is in the leaves, especially the older leaves near the bottom of the plant, so you want to avoid flowering. As the flowers begin to develop, the leaves start to lose their quality and start to become bitter.

Stevia is so sensitive to day length that you can set your calendar by it! One summer I grew stevia in an outdoor hydroponic garden. I brought it indoors on the first day of autumn (the equinox), and it started going to flower the next day! I tried extending the light period to 24 hours a day to bring them back to a vegetative state, but it was too late. All of the new growth went to flower, and I had to start new plants for the winter. So keep your stevia plants on long days from the very beginning to extend the harvesting season. You can continue to pluck off the bottom leaves of the plant any time that you need them. You can use the leaves fresh, or dry them for future use. For fun, try to take the smallest bite of a leaf tip that you possibly can, and chew it up a little. You will taste the sweetness of the leaf for an hour!

When harvesting, you can cut and hang the whole plant to dry, just like other herbs, or you can pluck off the leaves and put them on a drying rack. The veins of the leaves have a bitter aftertaste compared to the leaf tissue. So after the leaves are dry, I like to rub them between my hands over a large, stainless steel salad bowl. The veins remain in my hands, and I throw them away, but the tissue between the veins collects in the bowl. During the process, I can actually taste the sweetness in the dust from the air, and for a special treat, I get to sample a little of the white powder that collects on the sides of the bowl. It’s like pure, crystal sweetness!

Stevia is easy to use. Just steep a leaf in hot water to sweeten your herbal teas, or steep the leaves in milk and use it for baking. One of my favorite drinks is chocolate mint tea. I steep a few leaves from my chocolate mint plants together with my stevia leaves. It smells just like hot chocolate, and it has a wonderful after taste. There are whole cookbooks devoted to stevia, so don’t be afraid to try it! You will soon discover for yourself what Native Americans have enjoyed for centuries. Just remember, stevia is intensely sweet, and a little goes a long way. If you use too much, some of the bitter after taste starts to come through. But if you use just the right amount, it is guaranteed to put a smile on your face every time!

By Harley Smith