How to Grow Stevia

Days to germination: 7 to 10 days
Days to harvest: 90 to 100 days
Light requirements: Full sun with some light shade in the heat
Water requirements: Regular and frequent watering
Soil: Light loose soil
Container: Suitable, either outdoors or indoors

Introduction

Stevia is a very unique herb because unlike the other savory herbs used for flavoring, stevia is grown as a sweetener. Its leaves can be sweet enough to actually use as a replacement for sugar. There is a chemical called stevioside in the leaves that can be hundreds of times sweeter than true sugar (sucrose). It has no calories and won’t effect your blood sugar levels.

It may be a challenge to grow for new gardeners but that shouldn’t deter you from giving it a try. It’s an annual plant that will grow approximately 2 feet high. Even if you live in a warm climate with no winter frosts, stevia will still only survive for one year.

Starting from Seed

Stevia plants are very difficult to start from seed, so either purchase seedlings or sow more seed than you actually need. At least 3 times more. Watch for dark seeds, they are more likely to germinate. Pick out and discard any light brown or tan seeds because they are probably empty inside.

Start your seeds indoors, about 2 months before your expected final frost date. Don’t bury the seeds, rather sprinkle them on the top of the soil and keep moist. If you can provide “bottom heat” with a seed-heating pad, that is ideal to help stevia germinate.

Transplanting

Only after all frost is over should you think about putting out your stevia. Space your seedlings with approximately 8 to 10 inches between them, in a sunny location. The soil should be loose and well dug before you plant. Even adding some sand can help with drainage.

In areas with very hot summers, try to plan your stevia location so that your plants will get some daytime shading during the hotter months. Planting your stevia beside another plant that will be taller in the summer is one option.

Growing Instructions

Once your plants are growing well, surround them with a good layer of mulch. It will keep the moisture in the soil, and also prevent weeds from growing around your plants. Weeding around stevia can be difficult because its a brittle plant and you can easily damage the branches if you have to work too closely all the time.

Stevia grows best with a regular but light watering. You want the soil to be constantly moist rather than occasionally soaked. Water your plants 2 or 3 times a week, or even install a soaker hose to slowly water the plants over a period of time.

About 4 weeks after planting, pinch out the top leaf buds of the plant. This will keep it from growing too tall, and promote more side branches. A tall plant is more likely to bend and break in the wind.

Fertilizer isn’t usually necessary but if you are feeding your garden only use non-nitrogen formulas with stevia. It will promote leaf growth, but also reduce the sweetness overall. A fertilizer with boron will help your plants develop that sweet stevioside.

Containers

Stevia grows very well in containers and can even thrive if grown indoors. Keep your plants in a sunny location but its not crucial that it gets full sun all day. A little shade in the afternoons is fine to keep your stevia from getting too hot.

Each plant should have its own 12 inch pot, filled with a light soil. Potted plants usually dry out faster than your garden would, so it is especially crucial that you give your stevia regular and consistent waterings.

Pests and Diseases

Insects are not usually a big problem with stevia, though some larger animals like rabbit and deer can be attracted by the sweet taste of the leaves.

Aphids will sometimes feed on stevia, but very few insects are partial to the sweet leaves. A few sprays of insecticidal soap should keep your plans bug-free all summer.

Harvesting and Storage

Though you can harvest individual stevia leaves as the plant is growing, it won’t be at its sweetest until right before the flowers bloom. But once the flowers open, the leaves will almost immediately lost their taste and become bitter. This means you have a tight window to harvest your stevia for maximum sweetness.

As soon as you see the flower buds forming, harvest the entire plant by simply slicing through the main stem at ground level. Don’t try to pinch out the flowers because it won’t help. This will usually happen in late fall. Harvest your plants first thing in the morning if possible.

You can chew fresh stevia leaves for a sweet treat, but using fresh leaves in cooking or tea usually won’t have much impact. The leaves need to be broken up in order to release their stevioside compounds.

The best way to use and store your stevia is dried and ground. To keep the leaves tasting their best, they should be dried slowly. So don’t use a dehydrator or the oven. Hang the plants upside down in a dark, warm and ventilated area until the leaves thoroughly dry. Let them hang for 4 or 5 days if necessary.

The best way to grind your stevia is with a coffee grinder, but you can also use a standard food processor on its highest speed. Once ground fine, you can use it as a sugar substitute. Because it is so much sweeter than actual sugar so do a little trial and error before use. You won’t need very much. A rough guide is that 1 tablespoon of good stevia is as sweet as a cup of white sugar.

Store ground stevia in an air-tight jar out of the sunlight and it will last for a year.

You could also use the fresh leaves to make a liquid extract, but it’s a complicated process that involves steeping the leaves in alcohol and then cooking down the liquids. Most home-growers use the dried powder because its easier and does store better.

4 Responses to “How to Grow Stevia”

J Coulter Says:
June 25th, 2011 at 3:22 pm
After reading several sites about the growing of stevia, I’ve learned that it’s an annual and that it’s second season is probably its best and that after it’s third, it’s pretty much kaput. If it’s an annual, how does it have a second and third season?
ron Says:
July 28th, 2012 at 8:19 am
thank you on good info
sng Says:
August 10th, 2012 at 8:49 am
almost everything that you say about planting and keeping stevia is contradicted by almost all the other sites about stevia that I have read…why would that be?
Daniel aryenor Says:
October 10th, 2015 at 9:26 am
Iam so enthused about the plant stevia and how to plant it. How may get the stevia seed. Is there another way to propagate the plant apart from the seed