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) of waterlogged substrate (clay loam or aquatic planting soil) with 5–10 cm of standing water above the surface. EC 1.5-2.5 mS/cm (of the surrounding water). pH 6.0-7.5. Temperature: 18–32°C (tropical; corms form as days shorten in autumn, similar to oca). Full sun (DLI 15-22 mol/m2/day). Plant corms or divisions in spring; the rush-like stems grow through summer and 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, with yields of 0.5–2 kg per container. Peel the brown skin to reveal white flesh and eat raw, sliced and crisp, or add to stir-fries, salads and dim sum fillings; fresh water chestnut is far crunchier than the canned product.