How to Care for Stevia

Stevia (Stevia rebaudiana) is a tender, shrubby perennial grown as an ornamental for its bright green, softly serrated foliage and neat mounding habit. It is fast-growing and rewarding but frost-sensitive, so it is treated as an annual or overwintered indoors in cool climates.

Light

Stevia craves bright light. Give it full sun outdoors, at least 6 hours daily, or the brightest possible windowsill indoors (a south or west exposure) supplemented with a grow light in winter. In very hot inland climates a little afternoon shade prevents the thin leaves from scorching, but too little light produces weak, leggy stems.

Water

Keep the soil lightly and evenly moist, never soggy. Stevia has a shallow, fibrous root system that resents both drying out completely and standing water. Water whenever the top half-inch of soil begins to feel dry, and increase frequency during hot, windy weather when container plants can wilt quickly. Ease off in winter when growth slows.

Soil & Potting

Use a light, well-drained, humus-rich potting mix with plenty of organic matter to hold moisture without becoming waterlogged. Blending in perlite or coarse sand improves drainage. Choose a container with generous drainage holes; a wide, shallow pot suits the shallow roots. Outdoors, plant in loamy soil amended with compost and avoid heavy, poorly draining clay.

Humidity & Temperature

Stevia is a warm-season plant that thrives between about 65-85F (18-29C) and dislikes cold. Protect it from any frost, moving containers indoors when nights drop below about 50F (10C). It tolerates average household humidity but appreciates moderate to high humidity; in dry indoor air, grouping plants or using a pebble tray helps.

Feeding

Feed lightly and regularly through the growing season with a balanced, diluted liquid fertilizer every 3-4 weeks, or use a slow-release granular feed. Stevia responds well to steady low-nitrogen feeding, which supports leafy growth without forcing weak, floppy stems. Suspend feeding in fall and winter.

Propagation

Stevia propagates readily from softwood stem cuttings taken in late spring or summer. Snip a 4-6 inch tip, strip the lower leaves, and root it in moist potting mix or water in a warm, bright spot; roots form in a couple of weeks. Seed is possible but germination is often erratic and slow, so cuttings from a vigorous parent give faster, more uniform plants.

Repotting / Pruning

Pot up in spring when roots fill the container. Pruning is the key to a full plant: pinch the growing tips regularly starting when seedlings are a few inches tall to encourage branching and a compact, bushy shape. Removing the small white flower clusters as they appear keeps the plant leafy and prolongs vegetative growth, since flowering signals the plant to slow down.

Common Problems & Pests

Stevia is fairly trouble-free but can attract aphids, whiteflies, and spider mites, especially indoors or under stress. Rinse foliage and treat with insecticidal soap as needed. Overwatering and poor drainage lead to root rot and blackened stems, while too little light causes stretched, spindly growth. Good airflow and consistent moisture prevent most issues.

Seasonal Care Tips

Start or set out plants after the last frost once soil has warmed. Water and feed steadily through summer and pinch often for bushiness. As days shorten in fall, growth slows and the plant may try to flower; bring container specimens indoors before frost to overwinter in a bright, cool spot, cutting back on water and holding off on fertilizer until spring growth resumes.