Leaf amaranth
Amaranthus tricolor
Also known asChinese spinach · Een choy · Callaloo (some varieties) · Callaloo · Bayam · Hin choy
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 9–13 (winter low around -7°C)
- Frost
- frost sensitive (dies at first frost)
- Season
- warm (summer, frost-sensitive)
Growing systems
Root mass: moderate.
Growing media
| Medium | pH effect | Retention | Bacterial surface |
|---|---|---|---|
| Expanded clay pebbles (LECA) | neutral / inert | low | high |
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
| Soil-based mix (Potting soil) | varies | high | high |
| Rockwool (Mineral wool) | alkaline until pre-soaked | very high | low |
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 | 0.8 |
| vegetative | 3 | 1 | 2 | 1.6 |
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
Excellent hydroponic crop for warm conditions where lettuce and spinach won't grow. EC 1.5-2.5 mS/cm. pH 5.5-6.5. Temperature: 25–35°C (thrives in heat that destroys most leafy greens). Moderate to high light (DLI 15-25 mol/m2/day). Grows fast: baby leaves harvestable in 3-4 weeks from seed, full-sized leaves in 6-8 weeks. Works well in NFT, DWC, and vertical tower systems. Cut-and-come-again harvesting: take outer leaves and the plant continues producing from the center for weeks. Succession planting every 2-3 weeks ensures continuous supply. Nutrient demand is moderate; standard leafy green formula works. The plants bolt (go to seed) eventually but less quickly than lettuce in heat. Amaranth is relatively pest-free in hydroponic systems. The red and purple varieties add visual variety to salad mixes. In aquaponics, leaf amaranth thrives on the warm, nutrient-rich water that tilapia systems produce. One of the most practical warm-climate leafy greens for hydroponic and aquaponic growers. The leaves can be eaten raw in salads when young (baby leaf stage) or cooked like spinach when more mature. Cooking reduces the oxalic acid content. The red and purple varieties (A. tricolor 'Red Stripe', 'Red Leaf') add dramatic color to salad mixes. Amaranth is one of the few leafy greens that improves in quality with warm temperatures rather than declining, making it the ideal summer replacement for cool-season greens in hydroponic systems.