Stevia (Stevia Rebaudiana) is a perennial herb known as sugar leaf and candy leaf. You will understand why if you grow stevia at home and taste a leaf. Stevia is said to be 300 times sweeter than sugar. And trust me, the taste is very sweet.
We favor starting 3-5 seeds in square recyclable plastic starter pots. But for stevia, we will make an exception.
Stevia seeds are hard to germinate. The germination rate is low, and results where 3 of 10 seeds germinate are not unusual.
We have tried peat pellets, pots made from organic materials, grow bags, and self-made pots from newspapers. Still, the germination rate is poor.
I have had the most success with darker-colored seeds, whereas lighter-tanned colored seeds have produced lower germination rates.
When you grow stevia at home you learn that is an exciting herb. The seeds are challenging to germinate, and the seedlings grow slowly. But when the plant is established it will grow like a weed.
So let’s look at the best way to grow stevia from seeds.
How to grow stevia from seeds
1. Select your pot and soil
Stevia seeds are challenging to germinate even if you are careful and provide ideal conditions.
We use a larger-sized plastic pot to plant up to 10 seeds per pot. I usually get between 10-30 seeds per package when buying seeds.
I have tried several different vendors, but you should be fine if you use a reputable source and buy organic seeds.
The seeds want moist, well-drained soil. I use a 50 / 50 mixture of potting soil and a leaner cactus soil mix. I sprinkle a thin layer of vermiculite to prevent the seeds from drying.
2. Planting the seeds
Before planting the seeds, we water the soil lightly to eliminate any air pockets.
The stevia seeds are very fine and elongated and should be gently placed on the soil about 3 centimeters (1 inch) apart.
Using a larger pot will allow us to plant up to 10 seeds in one pot. It may seem excessive, but we cannot rely on a 100% germination rate.
Do not press the seeds with your fingers. Instead, cover them with a thin layer of vermiculite. If you do not have access to vermiculite, you can also cover them with potting soil. Using vermiculite will help us keep the growing environment moist.
When the seeds are planted, spray them with room-temperature water.
As seeds are planted on the surface, spraying the soil can move the seeds around the pot. Make sure you use the setting for fine mist, and you should be fine.
3. First leaves and seedlings developing
The stevia seeds will take 14-24 days to germinate.
And as we have already established, stevia seeds suffer from low germination rates.
We bottom water the pot when we see the first leaves or cotyledons. Simply put the pot in a water bath for 10-15 minutes. When the soil’s surface change color, remove the pot and let any excess water runoff.
The cotyledons are delicate, and using a spray bottle may push the leaves into the soil and kill the emerging seedling. Also, wet leaves may invite pets and diseases.
4. Transplanting stevia seedlings
Seedlings grow slowly, and we can expect to transplant them into larger pots after 6-8 weeks.
I use a potting soil mix of equal parts potting soil, peat moss, and sand or Perlite.
Transplant the seedlings to the same soil level as they were growing before.
We transplant each seedling into its pot or plant outdoors after hardening if the climate and time of year allow.
Stevia needs water and sun to thrive, so ideally, pick a location with at least 6 hours of sunlight per day.
5. Caring for the plant
Stevia will grow well outdoors in warmer climates.
But stevia doesn’t do well in cold temperatures. Stevia is native to South America and does not tolerate temperatures below 5 degrees Celsius (40 degrees Fahrenheit).
The plant can grow outdoors year-round if you live in a hot climate. For the rest of us, it is better to grow stevia in pots and bring the plant indoors as the weather gets cooler.
6. Harvesting and preserving stevia
The stevia plant is ready to be harvested about 40 days after transplanting. We harvest the leaves from the plant continuously throughout the season.
The leaves lose some of their flavors if we let the plant bloom.
We can also harvest and dry leaves to preserve them for later use. To dry leaves, use a dehydrator or an oven, or tie stems together and hang them in a light, airy, dry location without direct sunlight.
The dried leaves are easily crushed using a pestle and mortar. Do not crush them into a powder as you can always make the crumbs smaller later as needed,
If you use an oven, place the harvested leaves on a tray and set the temperature at 40 degrees Celsius (100 degrees Fahrenheit). Leave the door to the oven slightly open. Check on the result every now and then, but it will likely take a couple of hours. The leaves are done when they are dry to the touch but still green. The leaves should not turn brown.
Grow stevia at home from cuttings
If you can get a mature stevia plant, you will find it easy to grow stevia from cuttings.
1. Choose the location: Stevia needs sun; pick a spot with a least 6 hours of sun per day.
2. Prepare the soil: I mix regular potting soil, peat moss, sand, or Perlite. But any well-drained soil will do.
3. The cuttings: Cut well-established stems at least 15 centimeters (6 inches) long. Cut the stems just above a pair of leaves. Now cut off all leaves on the stem leaving only the top crown, usually 4 – 6 leaves.
4. Plant the cuttings in your pot: Now plant the cuttings by lowering about 5 centimeters (2 inches) of the cutting in the soil.
5. Water the cuttings: The stevia cuttings need moist soil to develop a healthy root system.
6. Transplant: When the cuttings are established, it is time to transplant them to a larger pot or herb garden.