New Zealand spinach
Tetragonia tetragonioides
Also known as: Warrigal greens, Botany Bay spinach, Cook's cabbage, Tetragonia
Quick facts
- Category
- leafy greens
- Difficulty
- beginner
- Days to harvest
- 55 to 80 days
- Harvest type
- cut leaves, plant regrows for repeated harvests
- Spacing
- 40 cm between plants
Environment
- Temperature
- 18–32°C
- pH
- 6 to 7.5
- EC (hydroponic)
- 1.5 to 2.5 mS/cm
- Daily light
- 16 to 25 mol/m²/day
Climate and zones
- USDA zones
- 8 to 12 (winter low around -12°C or warmer)
- Frost tolerance
- tolerates light frost
- Season
- warm (summer crops, frost-sensitive)
Viable growing environments:
- outdoor year-round (in zone)
- outdoor in growing season (annual)
- unheated greenhouse / hoop house
- heated greenhouse
- indoor (heated home)
- indoor hydroponics under grow lights
USDA zone bounds reflect outdoor year-round survival. Anywhere outside the bounded zone range, this crop still grows as an annual in the warm months (outdoor_seasonal), under cover (greenhouse), or indoors under lights.
Growing systems
New Zealand spinach works in:
- media bed (ebb and flow)
- wicking bed
- soil bed
- drip / Dutch buckets
Growing media
The substrate the roots sit in. Choice depends on the system (clay pebbles don't fit NFT channels; rockwool isn't used in media beds) and the crop (new zealand spinach works in the media listed below).
| Medium | pH effect | Water 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 by source | high | high |
Bacterial surface area matters for aquaponics: clay pebbles, lava rock, and pumice double as biofilter substrate. Low-surface media (rockwool, perlite, pea gravel) work in hydroponics but need a separate biofilter in aquaponics.
Nutrient demand by stage
NPK ratios are relative weights at each growth stage; the nutrient mix calculator scales them to absolute grams or ml. EC targets shift through the plant's life: seedlings need a much lighter solution than fruiting adults.
| Stage | N | P | K | EC target (mS/cm) |
|---|---|---|---|---|
| seedling | 1 | 1 | 1 | 0.8 |
| vegetative | 3 | 1 | 2 | 1.8 |
Aquaponics suitability
Compatible with typical aquaponics nutrient profiles. 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 during summer when true spinach won't grow. EC 1.5-2.5 mS/cm. pH 6.0-7.5. Temperature: 20–32°C (warm-season; frost kills the plant, but it thrives in heat that destroys lettuce and spinach). Moderate to high light (DLI 14-22 mol/m2/day). DWC, media beds, or containers. Seed germination is slow and irregular (soak seeds in warm water for 24 hours before planting to improve germination). From seed to first harvest: 7-9 weeks (slow to establish). Once established, the plant produces continuously for months, growing larger and more productive over time. Harvest by picking individual leaves and tender stem tips (the stems are also edible when young). The leaves are slightly thicker and more succulent than true spinach; use them the same way (raw in salads when young, cooked as a spinach substitute in any recipe). The mild, slightly salty flavor is pleasant. For aquaponics systems that run through hot summers, New Zealand spinach fills the leafy-green production gap that exists when lettuce and true spinach bolt.
Plan a setup with New Zealand spinach
Verified against: rhs-uk, university-of-florida-ifas. Last reviewed 2026-05-15.