When most people think of ‘Stevia’, they think of the powdered green (or white… if it’s been bleached) stuff used as an alternative sweetener you can buy from most supermarkets. But it doesn’t start out that way. Stevia is an herb that you can grow in your garden.
It’s always a fun experience to invite someone to taste a leaf of the plant, and for them to realize what it is. It’s pretty cool when it’s an exciting experience for someone. I usually like to do the “Hey try this” with Cinnamon Basil or Lemon Basil. Another good one is German Chamomile flowers or Lemon Grass… more for pressing between your fingers and smelling. Maybe it’s because I hope that if I can get people to start experiencing bits of the amazing-ness of plants, they’ll start growing more of their own (though Carrie and her husband Corey already to grow tomatoes and flowers).
Now, about stevia. I get a lot of questions about it, so I thought I’d give you a quick brief on it, according to my experience in growing it.
Stevia is actually a whole group of plants in the Asteraceae (daisy) family. The single plant prized for its sweet leaves is Stevia rebaudiana (so be sure that’s what you’re getting when you’re purchasing seeds). Some say that growing from seed won’t produce a sweet plant, or that you’re less likely to get a sweet plant… but in my case, it’s clearly very sweet (about a quarter of a leaf is more than enough to sweeten a cup of tea).
You can also purchase S. rebaudiana as a seedling, usually when it’s about 4-8 inches tall, so ask your local nursery about that. It may be easier to start with a seedling because, from my experience, Stevia rebaudiana is a rather finicky plant to start from seed. Once it’s growing, though, it grows very well. I managed to get six seedlings to come up at this past spring, but only one made it all the way to adult-hood. It’s a sturdy plant once it’s become established. It produces fairly thick, tall stalks, but you can keep it lower and bushier if you pinch it back every few weeks. I didn’t want to do that in its very first season, since I was finding it a bit hard to keep any of them alive past 3 or 4 inches of growth, so I was happy to just let it grow and become stronger and more established this year.
If you just let it grow and reach its full height, it’ll begin to put out flower heads once the stalk reaches 2-3 feet tall. The leaves become very sweet as the flower heads begin to appear, and that’s just about the time you want to cut the stalks and dry the leaves.
Cut the stalk about 6 inches above the ground, right above a set of leaves. The plant will sprout two new stems right above each of the leaves (as you can see in the picture at the bottom right). These stalks were cut about a week earlier, and already you can see the growth of two new stems right above each of the leaves.
I found that S. rebaudiana likes a good dose of water nearly every day (and sometimes twice a day when it gets hot, especially if it’s in a container), but the container/soil needs to drain very well so it’s not standing in water, and has enough time to dry in between waterings. I used sifted compost and sand to create a good, healthy mix for my stevia, and it worked very well. If stevia gets too wet or the roots sit in water too often or too long, it can be affected by fungal disease, so good drainage is a must.
I wanted to use compost, because a stevia plant that is fed with a nitrogen fertilizer will keep the leaves green, and perhaps produce more leaves, but they won’t be as sweet, and sweetness was my goal. So to keep the plant healthy, with plenty of nutrients, without compromising the sweetness, compost seemed to be the best option and it worked well with a good dose of sand mixed in.
A common garden fertilizer without nitrogen in it would work well, too. On the last note of nutrients – I have heard that fertilizing your stevia plant with Boron will increase its sweetness (perhaps boron is part of the process of making the sweetener that stevia plants produce), but I haven’t verified that claim.
There is a new ‘North American Stevia’ plant, which has been developed to contain less of the stevioside and more of the Rebaudioside A. Both are sweetener chemicals, but the stevioside has a slightly bitter aftertaste, and the North American Stevia plant has been developed through cross-pollination and selection, to have less of the stevioside chemical in it, and more of the Rebaudioside A chemical, so you don’t get very much of the bitter aftertaste.
The packet of seeds I grew did not indicate that it was one of these or not, so I don’t know which one I have. The leaves on my plant are definitely sweet, and I don’t taste much of a ‘bitter’ aftertaste, though it is certainly a different sweetness from sugar… and maybe an ‘off’ aftertaste lingers a bit on the tongue. If you want to be sure to get the new North American Stevia plant, it would probably be best to purchase one as a seedling, since cuttings are guaranteed to be true to the mother plant.
The stevia stalks grew tall and strong, but they were a bit brittle, so I took care to stake them, and I’m glad I did. The tallest stalk had the top snapped cleanly off during a very windy storm over the summer… the one bit that I hadn’t supported with some stakes and rope, so I was glad I’d supported the rest of the plant.
Grow your stevia in full sunlight. The more sun, the more the plant will produce the sweetness in the plant, and the healthier the plant will be.
I’ll be overwintering my inside, which is why I grew it in a pot, because it is a very tender perennial. If you grow it in the ground, you can either lift it and pot it up to bring it inside for the winter (if you’re colder than zone 9), or you can harvest it the stalks and let the plant die, and then just grow it again the next year. If you overwinter it inside, be on the lookout for white fly. If your plant is being attacked by whitefly, spray the plant with a Insecticidal soap, or a dilute mixture of water and household dish soap (making sure it doesn’t have perfumes or other chemicals in it that may harm your plant). Or you can make a sticky trap with contact paper and a small stake.
The seeds are fairly expensive, as far as seeds go. Once you’ve got an established plant, you can propagate it with stem cuttings, which are more likely to be successful if you use a rooting hormone powder. I’ll be trying that myself in a few days, so I’ll give you an updated post to let you know how it goes.
To use stevia in cooking, once you’ve harvested the stalks, hang them upside down to dry until the leaves are brittle. Or you can pull the leaves off the stem immediately and spread them out to dry on a screen. Once they’re brittle, you can pull them off the stem and store them in an airtight container, or you can powder them (either manually or with a food processor) before storing them. Then, when cooking, add a measured amount of the stevia powder to recipes. Remember that because stevia powder doesn’t have the same properties as sugar, other ingredients in the recipe may need to be adjusted to retain moisture levels, rising action, etc. to compensate for the decreased amount of sugar.
I found a great Pinterest board with a bunch of recipes for stevia bookmarked. I think you’ll find it useful. I can’t wait to try some of the recipes on there myself.
For my herbal teas, I just add a bit of a leaf to stew with the other herbs. I can use the same leaf at least 2 or 3 times with great results.
I hope you enjoy growing and using stevia! Below are some pictures of the growth of our stevia plant throughout the summer. I thought you’d find them interesting.