Stevia
Stevia rebaudiana
Also known asSweet leaf · Sugar leaf · Candyleaf · Yerba dulce
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 9–12 (winter low around -7°C)
- Frost
- frost sensitive (dies at first frost)
- Season
- year-round tropical
Growing systems
Root mass: moderate.
Growing media
| Medium | pH effect | Retention | Bacterial surface |
|---|---|---|---|
| Rockwool (Mineral wool) | alkaline until pre-soaked | very high | low |
| Expanded clay pebbles (LECA) | neutral / inert | low | high |
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
| Net pot, no medium (Bare-root) | - | - | - |
| Soil-based mix (Potting soil) | varies | high | high |
Nutrient demand by stage
NPK ratios are relative weights. EC targets shift through the plant's life.
| Stage | N | P | K | EC (mS/cm) |
|---|---|---|---|---|
| seedling | 1 | 1 | 1 | 0.6 |
| vegetative | 3 | 1 | 2 | 1.5 |
Aquaponics suitability
Compatible
Fish waste provides enough nitrogen for healthy growth. Supplemental potassium, calcium, and iron may still be needed depending on fish stocking density.
Care notes
An easy, compact perennial herb for hydroponic systems. EC 1.0-2.0 mS/cm. pH 5.5-7.0. Temperature: 18–30°C (subtropical origin; frost-sensitive, but tolerates moderate heat). Moderate to high light (DLI 14-22 mol/m2/day; sweetness concentration increases with strong light). NFT, DWC, Kratky, or container systems. From transplant to first harvest: 6-8 weeks (propagation from seed is slow and erratic; stem cuttings or purchased plants are more practical). Harvest by cutting stem tips; the plant branches and regrows. The sweetness is concentrated in the leaves; stems have less flavor. For tea sweetening: add 2-3 fresh leaves to a cup of tea (the sweetness is intense; start small). For dried stevia powder: dehydrate leaves at 40–50°C, crush to powder, use sparingly. The dried powder has a slight herbal aftertaste that some find objectionable; the fresh leaves have a cleaner sweet flavor. A single stevia plant provides enough sweetener for a household's tea and herb-tea consumption.