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 1.2-1.8 mS/cm. pH 5.5-7.0. Temperature: 18–30°C (subtropical origin; frost-sensitive but tolerates moderate heat). Moderate to high light (DLI 16-24 mol/m2/day; sweetness concentration increases with strong light). NFT, DWC, Kratky or container systems. From transplant to first harvest: 6-8 weeks; seed propagation is slow and erratic, so stem cuttings or purchased plants are more practical. Harvest by cutting stem tips and the plant branches and regrows. The sweetness is concentrated in the leaves, with little in the stems. For tea, add 2-3 fresh leaves to a cup (the sweetness is intense, so start small). For dried powder, dehydrate leaves at 40–50°C, crush and use sparingly; the dried powder carries a slight herbal aftertaste that the fresh leaf lacks. One plant supplies enough sweetener for a household's tea.