New Zealand spinach
Tetragonia tetragonioides
Also known asWarrigal greens · Botany Bay spinach · Cook's cabbage · Kokihi · Sea spinach · Tetragon
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 8–12 (winter low around -12°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 |
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 | 1.8 |
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
A warm-season spinach alternative for hydroponic systems through summer, when true spinach won't grow. EC 1.5-2.5 mS/cm. pH 6.0-7.5. Temperature: 18–32°C (warm-season; frost kills the plant, but it thrives in heat that ruins lettuce and spinach). Moderate to high light (DLI 16-25 mol/m2/day). DWC, media beds, or containers. Seed germination is slow and irregular, so soak seeds in warm water for 24 hours before sowing. From seed to first harvest: 7-9 weeks (slow to establish). Once going, the plant produces continuously for months, getting larger and more productive over time. Harvest by picking individual leaves and tender stem tips, which are also edible when young. The leaves are thicker and more succulent than true spinach; use them the same way, raw in salads when young or cooked as a spinach substitute. The flavour is mild and faintly salty. For aquaponics systems running through hot summers, New Zealand spinach fills the leafy-green gap left when lettuce and true spinach bolt.