Herb · Asteraceae
Stevia
Stevia rebaudiana
Grow your own no-calorie sweetener from a leaf you can chew right off the plant.
Full sun
Every 2–4 days
50–90°F · 10–32°C
90–110 days
Overview
Stevia is a tender herb from the highlands of Paraguay, where people have used its leaves to sweeten food and drink for generations. The leaf carries natural compounds called steviol glycosides that taste many times sweeter than sugar yet add no calories. Chew a fresh leaf and the sweetness hits right away.
As a garden plant it stays small and bushy, reaching only 18 to 30 inches (45 to 75 cm) tall. It's a perennial in warm climates but frost-tender everywhere else, so most gardeners treat it as a warm-season annual or pull a potted plant indoors before winter. It settles in just as well in a sunny bed as in a container on a balcony.
The plant asks for a little attention to stay sweet. Keep pinching the tips to build a fuller bush and snip off flower buds as they form, because the leaves lose their edge once the plant blooms. Get the timing right and a single plant gives you sweet leaves all summer long.
Care
The short version: full sun, steady moisture in well-drained soil, and a regular pinch of the tips and flower buds to keep the leaves coming and the sweetness high.
Light
Stevia wants full sun, ideally six or more hours a day, which is what keeps the leaves growing thick and sweet. It tolerates a little afternoon shade where summers run hot, but deep shade leaves you with a thin, leggy plant.
Water
Keep the soil consistently moist but never waterlogged, since the roots sit shallow and dry out fast. Water every 2 to 4 days, more often in heat or in a pot, and lay down mulch to hold the moisture in.
Soil
Plant in well-drained loam rich in organic matter, which feeds the plant while letting excess water drain away. Stevia takes a wide pH band from 6.0 to 7.5, so most garden soil suits it without fuss.
Temperature
Stevia grows best in the warm range of 50°F to 90°F (10°C to 32°C). It's frost-tender at the low end and a freeze will finish it, so bring potted plants in before the first cold snap.
Humidity
Average humidity around 40% to 70% keeps stevia content, which covers most outdoor and indoor settings. Good airflow matters more than chasing a number, since crowded, damp leaves invite pests and rot.
Feeding
Feed monthly through spring and summer with a balanced, low-nitrogen organic fertilizer. Go easy here on purpose, because too much nitrogen pushes leafy growth at the cost of the leaf sweetness you're after.
Pruning
Pinch the growing tips often to build a bushy, well-branched plant. Just as important, snip out flower buds the moment they appear, since the leaves taste sweetest and grow most freely before the plant blooms.
Repotting
Repot once a year, or whenever you bring the plant indoors to overwinter, moving up to a slightly larger pot with fresh mix. Watch for roots circling the pot, slowed growth, or soil that dries out almost as soon as you water it.
Size & spacing
Plants reach 18 to 30 inches (45 to 75 cm) tall and spread 12 to 24 inches (30 to 60 cm) wide. Give each one that much room so air moves freely between them and the leaves stay dry.
When to plant
Stevia wants warmth and won't tolerate frost. Start the seeds or cuttings indoors in late winter, set the plants out only after the cold has fully passed and the soil has warmed, and harvest leaves through summer up to the first frost.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 8-10 weeks before the last spring frost
- Plant: after all danger of frost has passed and soil has warmed to at least 50°F (10°C)
- Harvest: Harvest leaves through summer; pinch flowers as leaves are sweetest before bloom. Main leaf harvest before flowering in late summer/early fall.
Hardiness
USDA hardiness zones: 9–11
Temperature: down to -7°C
Troubleshooting
Most stevia trouble shows up on the leaves, whether from pests, soggy roots, or the plant slipping into bloom. Catch the early signs and you can step in before the harvest suffers. Match what you see below, then act while it still helps.
Wilting in wet soil with dark, mushy roots
When a plant wilts even though the soil is soaked, suspect root rot from waterlogged ground. The roots turn brown and soft, and once they go there's no bringing them back. Cut back on water at once, improve the drainage or repot into a fresh, fast-draining mix, and never let a container stand in a saucer of water.
Fix:
- Reduce watering immediately
- Improve soil drainage or repot into well-drained mix
- Remove and discard severely affected plants
Foliage suddenly black and limp after a cold night
Stevia is frost-tender, so a single freeze turns the foliage black and limp overnight. Move potted plants indoors before the cold arrives. If frost catches the plant first, cut back the damaged growth and overwinter it inside until spring.
Fix:
- Move container plants indoors before frost
- Cut back damaged growth and overwinter the plant indoors
Curled, sticky leaves with tiny insects underneath
This is the work of aphids or whiteflies, sap-feeders that gather on the leaf undersides and leave a sticky film of honeydew behind. Knock them off with a strong jet of water, then treat the leaves with insecticidal soap if they keep coming back. Pull off any leaf that's badly overrun.
Fix:
- Spray plants with a strong jet of water to dislodge insects
- Apply insecticidal soap to affected foliage
- Remove and destroy heavily infested leaves
Ragged holes chewed in the leaves near the ground
Slugs and snails chew these holes overnight and in wet weather, leaving shiny slime trails on the foliage and soil. Pick them off by hand after dark, when they come out to feed. Clear away mulch and debris near the plant so they have nowhere to hide during the day.
Fix:
- Hand-pick slugs in the evening
- Remove debris and mulch that harbor them
- Use slug traps or barriers around plants
Leaves losing their sweetness as buds appear
Once flowering starts, the plant pours its energy into blooms and the leaves turn less sweet and slow to come. Pinch out the flower buds the moment you spot them at the stem tips. Harvest your main crop before the plant blooms, when the leaves carry the most sugar.
Fix:
- Pinch out flower buds as they form
- Harvest leaves before full bloom
Toxicity
Stevia is one of the safest plants you can grow at home. The leaf is an edible, no-calorie sweetener used in kitchens worldwide, and it isn't listed as toxic to cats, dogs, or other animals. A nibble from a curious pet is nothing to worry about.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Stevia is safe around cats and isn't on the ASPCA toxic list. A curious nibble does no harm, though gulping down a big pile of any leaf can still leave a cat with a passing stomach upset.
Dogs None
Dogs can be near stevia with nothing to worry about. The leaves carry no toxin, and the worst a greedy mouthful is likely to bring is some mild, short-lived gas or loose stool.
Horses Safe
The plant poses no danger to horses. They can graze a stray sprig without trouble, since the leaf holds the same sweetener people use every day.
Rabbits Safe
Rabbits handle stevia fine. The sweet leaf makes a safe occasional treat, but keep it small so their diet stays mostly hay and greens.
Livestock Safe
Goats, sheep, and cattle can browse stevia without harm. It's grown as a food crop, so there's nothing in the foliage to trouble grazing animals.
Birds Safe
Backyard hens and pet birds are fine pecking at the leaves. There's no toxin here, just an unusually sweet bite of green.
People Safe
People grow stevia precisely to eat it. The leaves are a no-calorie sweetener you can chew fresh or dry, and they're regarded as safe for the whole family.
Leaves are edible and used as a natural sweetener; no special handling precautions are required.
Varieties
Most stevia is sold simply as stevia, but a few named selections are worth seeking out for sweeter leaves or better container growth.
Sweet Sugar Leaf
A widely grown selection prized for its high steviol glycoside content, which gives the foliage an especially sweet bite.
Candy
A compact, productive cultivar bred to grow reliably in a pot while still delivering plenty of sweet leaves.
How to propagate
Stevia can be raised from seed or cuttings, but the two are not equal. Seed is slow and unreliable, while cuttings root fast and give you an exact copy of a plant you already like.
SeedDemanding
Start indoors 8-10 weeks before the last spring frost · Germination in 1-3 weeks, but often poor and erratic
Starting from seed is the hard way with stevia. Sow indoors 8 to 10 weeks before your last spring frost, but be ready for trouble, since the seed has low viability and sprouts unevenly over 1 to 3 weeks. Because so many seeds fail, most growers skip them and take cuttings instead.
Stem cuttingsModerate
Spring through summer from healthy non-flowering shoots · Roots in 2-4 weeks
Cuttings are the dependable route. Take softwood tip cuttings from healthy, non-flowering shoots anytime from spring through summer, push them into moist media, and they root in about 2 to 4 weeks into plants identical to the parent.
Myths
Stevia leaves taste bitter straight off the plant.
Pick a fresh leaf and chew it and you get a clean, intense sweetness, not bitterness. The sweetness peaks before the plant flowers, so harvest your main crop while the buds are still tight.
Stevia is a hardy perennial that survives winter outdoors.
It's a true perennial in warm climates, but it's also frost-tender and dies back at the first freeze. In cold regions most gardeners grow it as an annual or bring a potted plant indoors to carry it through winter.