Chinese water chestnut
Eleocharis dulcis
Also known asMatai · Ma tai · Chinese sedge · Eleocharis tuberosa · Pi qi
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
- 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 |
| Lava rock (Scoria) | neutral / inert | low | very high |
| 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 | 0.8 |
| vegetative | 2 | 1 | 3 | 2 |
Companion-growing notes
- Heavy uptake of potassium. Co-grown crops with the same demand will end up deficient even at "correct" EC.
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 aquatic crop grown in waterlogged conditions, well-suited to aquaponics integration. Grow in large, shallow containers (30 cm wide, 15–20 cm deep) filled with waterlogged substrate (clay loam, aquatic planting soil) and 5–10 cm of standing water above the substrate surface. EC 1.5-2.5 mS/cm (the water surrounding the containers). pH 6.0-7.0. Temperature: 25–32°C (tropical; the corms form as days shorten in autumn, similar to oca). Full sun (DLI 18-25 mol/m2/day). Plant corms or divisions in spring. The rush-like stems grow throughout summer. Corms form at the tips of underground stolons in autumn. Harvest by digging through the waterlogged substrate in late autumn, feeling for the small, round corms. Yields: 0.5–2 kg per container. Peel the brown skin to reveal white flesh. Eat raw (sliced, crispy, mildly sweet) or add to stir-fries, salads, or dim sum fillings. The crunch of a fresh water chestnut is incomparably superior to the canned product.