Herbs

Stevia rebaudiana

Stevia

Asteraceae

Paraguay, Brazil (subtropical highlands)

At a Glance

TypePerennial
HabitUpright
FoliageDeciduous
Height12-24 inches (30-60 cm)
Width12-18 inches (30-45 cm)
Maturity1 years

Growing Zones

USDA Hardiness Zones

9 - 11
Zone 9
Zone 10
Zone 11
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancetender

Key Features

Attracts Pollinators
Deer Resistant
Container Friendly
Maintenancemoderate

Overview

Stevia rebaudiana is a bushy, erect, semi-woody perennial herb in the daisy family (Asteraceae) reaching 12–24 inches (30–60 cm) tall with a 12–18 inch (30–45 cm) spread. Stems are erect, branching, slightly woody at the base, green, lightly pubescent. Leaves are opposite, ovate to lanceolate, 1–2.5 inches (2.5–6 cm) long, medium green, with toothed margins. The defining feature is the intense sweetness of the leaves — chewing a fresh leaf produces a sweetness 200–300 times that of sugar by weight, from steviol glycosides (stevioside, rebaudioside A). The sweetness has a slight bitter or licorice-like aftertaste in some cultivars. Flowers are small, white, in terminal corymbs of 3–5 heads, typical Asteraceae composite structure. Hardy only to USDA zone 9; in the Pacific Northwest (zones 7–8), stevia is grown as an annual or overwintered indoors in containers. Does not tolerate frost. Short-day flowering (triggered when day length falls below 13 hours) limits seed production in northern latitudes.

Native Range

Native to the subtropical highlands of Paraguay and Brazil (Amambay department), occurring in sandy, acidic soils at 500–1,500 feet (150–460 m). Used by the Guaraní people for centuries as a sweetener (ka'a he'ê, meaning "sweet herb"). Commercial cultivation began in Japan in the 1970s.

Suggested Uses

Planted in herb gardens, balcony containers, and kitchen windowsill gardens. Fresh leaves are chewed as a natural sweetener, added to tea, or dried and powdered as a sugar substitute. The intense sweetness (200–300× sugar) makes stevia the primary non-caloric natural sweetener plant. The taste test comparing stevioside sweetness to sugar is a sensory identification exercise. The steviol glycoside chemistry, the Guaraní ethnobotanical history, and the short-day flowering physiology are teaching topics in herb identification courses.

How to Identify

Distinguished from other Asteraceae herbs by the intense sweetness when a leaf is chewed — no other common garden herb produces this level of sweetness. The opposite, toothed, medium green leaves on a bushy semi-woody plant are nondescript until the taste test. Distinguished from Nepeta cataria and Melissa officinalis by the sweet (versus minty or lemon) flavor. The chew-a-leaf taste test is definitive.

Appearance

Size & Dimensions

Height1' - 2'
Width/Spread1' - 1'6"

Reaches mature size in approximately 1 years

Colors

Flower Colors

white

Foliage Colors

green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~3 weeks
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Fall
Flowers in late September through October as day length drops below 13 hours (short-day plant). Small white composite flowers in terminal corymbs. Seed viability is often low; propagation by stem cuttings is more reliable. In the Pacific Northwest, flowering coincides with the first frost risk, often preventing seed maturation.

Detailed Descriptions

Flower Description

White

Foliage Description

Medium green, ovate to lanceolate, with toothed margins; intensely sweet when chewed

Growing Conditions

Sun Requirements

Full Sun
Requires 6-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.0(Neutral)
357912
Soil Types
loamsandsilt
Drainage
well drained

Water & Climate

Water Needs

Medium

Frost Tolerance

tender

Time to Maturity

1 year

Care & Maintenance

Care Guide

Start from nursery transplants or rooted stem cuttings in spring after the last frost. Space 12–18 inches (30–45 cm) apart in full sun with well-drained, consistently moist soil. Does not tolerate frost; in the Pacific Northwest (zones 7–8), grow as an annual or in containers brought indoors before first frost. Container culture (2+ gallon) is the standard method for balcony and windowsill herb gardens in cold-winter regions. Pinch stem tips regularly to encourage bushy, branching growth and delay flowering. Harvest leaves before flowering for the highest steviol glycoside concentration. Propagate by 4-inch (10 cm) stem tip cuttings rooted in moist perlite.

Pruning

Pinch stem tips every 3–4 weeks through summer to encourage branching and delay flowering. Harvest entire stems by cutting back to 4 inches (10 cm). If overwintering indoors, cut back to 4 inches and maintain in a bright window.

Pruning Schedule

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summer

Maintenance Level

moderate

Container Growing

✓ Suitable for container growing

Minimum container size: 2 gallons

⚠️ Toxicity Warning

Non-toxic

Planting Guide

Planting Methods & Timing

Planting Method

transplant

Indoor Start

10 weeks before last frost

Days to Maturity

120–150 days

Plant Spacing

18 inches