New Zealand spinach (Tetragonia tetragonioides) is a leafy green vegetable native to coastal regions, prized as a heat-tolerant alternative to true spinach (Spinacia oleracea), to which it is not botanically related. It belongs to the Tetragoniaceae family and is well suited to warm-season growing when conventional spinach struggles and bolts.

The plant produces succulent, triangular, dark green leaves with a slightly fleshy texture. It grows low to the ground, spreading to form a dense mat that suppresses weeds and helps retain soil moisture — a useful trait in drier gardens.

The flavour is mild, slightly salty, and similar to traditional spinach, though with a more robust character. It is rich in vitamins A and C, calcium, and iron. While edible raw in small quantities, it is most commonly cooked — steaming, sautéing, or adding to soups, stews, and stir-fries reduces its oxalate content, which in large raw amounts can inhibit calcium absorption.

Gardeners value New Zealand spinach for its impressive heat and drought tolerance, low maintenance requirements, and prolific yields over a long harvest season. It is relatively resistant to common pests and diseases, making it an excellent choice for sustainable, low-input vegetable growing.

How To Grow

Growing New Zealand Spinach

Site Selection

Choose a position in full sun to partial shade. New Zealand spinach tolerates more heat than traditional spinach, and partial shade can help maintain leaf quality during the hottest periods. It is naturally coastal and handles wind well.

Soil Preparation

Prefer well-drained, sandy or loamy soil enriched with compost or well-rotted organic matter. Aim for a soil pH of 6.0–7.5. In heavy clay soils, incorporate grit and compost to improve drainage. Poor drainage is one of the few conditions this plant dislikes.

Sowing Seeds

• Timing: Sow after the last frost date, when soil has warmed to at least 20°C. Seeds can be started indoors 4–6 weeks before the last frost for an earlier start.
• Seed preparation: Soak seeds in warm water for 12–24 hours before sowing to soften the hard seed coat and improve germination rates.
• Depth: Sow seeds approximately 1–2 cm deep.
• Spacing: Space plants 45 cm apart in rows 60 cm apart. Plants spread widely, so adequate spacing is essential.
• Germination: Expect germination in 10–20 days at optimal temperatures.

Watering

Keep soil consistently moist until seedlings are established. Once mature, New Zealand spinach is drought-tolerant, but regular watering produces more tender, palatable leaves. Avoid waterlogging.

Mulching

Apply a generous layer of organic mulch (straw, leaf mould, or wood chip) around plants to conserve moisture, suppress weeds, and moderate soil temperature.

Feeding

Side-dress with balanced compost or apply a liquid fertiliser every 4–6 weeks during the growing season to sustain vigorous leafy growth.

Thinning and Maintenance

Thin seedlings to prevent overcrowding. Keep the growing area weed-free, especially while plants are young. Once established, the spreading habit will outcompete most weeds naturally.

Harvesting

Harvesting New Zealand Spinach

When to Begin Harvesting

Begin harvesting when plants are approximately 15–20 cm tall, typically 8–10 weeks after sowing. The plant grows rapidly in warm conditions, and regular harvesting is key to maintaining production throughout the season.

How to Harvest

• Use clean, sharp scissors or garden shears to cut stems cleanly and reduce the risk of disease.
• Harvest young, tender shoot tips and leaves — these offer the best flavour and texture. Older leaves can become coarse.
• Cut stems 2–5 cm above a leaf node to encourage vigorous regrowth from the cut point.
• Harvest regularly, ideally every 1–2 weeks during peak growth. Frequent picking encourages bushy, productive plants and prevents excessive sprawl.

How Much to Take

Never remove more than one-third of the plant at a single harvest. Retaining sufficient foliage ensures the plant can continue to photosynthesise and recover quickly.

Post-Harvest Care

• Rinse harvested leaves and stems thoroughly in cool water.
• Dry gently with a clean towel or salad spinner before storing.
• Store in a sealed container or bag in the refrigerator for up to one week.

Encouraging Continued Production

• Water consistently after harvesting to support rapid regrowth.
• Apply a liquid feed or compost tea to replenish nutrients following heavy cuts.
• In warm climates without frost, plants may continue producing for many months, often self-seeding for the following season.

> Tip: Cooking New Zealand spinach (steaming or sautéing) reduces its oxalate content, which in large raw quantities may inhibit mineral absorption.

Common Problems

Common Problems with New Zealand Spinach

New Zealand spinach is generally a robust, low-maintenance plant, but a few issues can occasionally arise:

Pests

• Aphids: Small colonies may appear on tender new growth. Blast off with a strong jet of water or apply insecticidal soap. Encouraging natural predators such as ladybirds and lacewings helps keep populations in check.
• Leaf miners: Larvae tunnel through leaves, leaving pale winding trails. Remove and destroy affected leaves promptly. Avoid leaving crop debris in the garden.
• Slugs and snails: Young seedlings are vulnerable. Use physical barriers, copper tape, or traps. Apply organic iron-phosphate-based pellets if infestations are severe.

Diseases

• Fungal issues (downy mildew, damping off): Most likely in humid, poorly ventilated conditions or where plants are overcrowded. Improve spacing, avoid overhead watering, and water at the base of plants in the morning.
• Root rot: Caused by waterlogged soil. Ensure good drainage at planting and avoid overwatering. Raised beds help in wetter climates.

Environmental Problems

• Poor germination: Often caused by cold or dry soil. Ensure soil temperature is at least 20°C before sowing, and soak seeds for 12–24 hours beforehand.
• Bolting / flowering: Less of an issue than with true spinach, but plants will eventually flower and set seed in long seasons. Regular harvesting delays this. Allow a few plants to self-seed if desired.
• Leggy or sparse growth: Usually indicates insufficient sunlight or nutrients. Move to a sunnier position or feed with a nitrogen-rich fertiliser.