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How to Grow Okinawan Spinach

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Okinawan Spinach

Alternanthera sissoo

vegetable

Okinawan spinach is a tropical leafy green vegetable native to Central and South America, widely cultivated in Okinawa and other warm climates. It features heart-shaped leaves on climbing or trailing stems and thrives in hot, humid conditions where traditional spinach struggles. The plant is nutrient-dense and is often used in Asian cuisine as a heat-tolerant spinach substitute.

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Example Okinawan Spinach timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Okinawan Spinach

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Okinawan Spinach

    Around May 17

    ≈ 30 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Okinawan Spinach dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun to partial shade; 6-8 hours of sunlight daily, tolerates afternoon shade in very hot climates
💧
Water: Keep soil consistently moist but not waterlogged. Water deeply 2-3 times weekly; increase frequency in hot weather. Prefers humid conditions and benefits from regular misting in dry climates.
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Spacing: 12 inches
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Days to maturity: 30-50 days to first harvest; continuous harvest thereafter
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Planting depth: 0.25 inches for seeds; transplants at soil line

Soil

Type: Well-draining loamy soil rich in organic matter
pH: 6.0-7.0
Amendments:
Compost Aged manure Peat moss or coco coir Balanced organic fertilizer

Growing Zones

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Thrives in zones 9b-12; can be grown as an annual in cooler zones or indoors

9b 10a 10b 11a 11b 12a 12b

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Growth Stages

1

Seedling

1-2 weeks

Small heart-shaped cotyledons emerge; first true leaves appear ovate and tender

Keep soil warm (70-85°F) and consistently moist. Provide bright indirect light until true leaves develop. Thin seedlings to prevent overcrowding.

2

Vegetative Growth

2-3 weeks

Plant develops multiple stems with heart-shaped leaves; vigorous branching occurs. Stems may climb or trail depending on support provided.

Provide support structure (trellis, stakes, or allow to trail). Pinch back growing tips to encourage bushier growth. Fertilize every 2-3 weeks with balanced fertilizer.

3

Leaf Production

4-6 weeks (or longer with proper care)

Plant enters prolific leaf-producing phase with dark green, succulent foliage. Stems become woody at the base while tips remain tender.

Begin regular harvesting to encourage continued production. Maintain consistent moisture and humidity. Monitor for pests in warm, humid conditions.

4

Flowering

Ongoing as long as growing conditions persist

Small, inconspicuous whitish or purplish flowers appear on branch tips. Flowering typically occurs in longer day lengths or when plant matures.

Continue harvesting leaves; flowering doesn't significantly reduce leaf quality. Deadhead spent flowers if desired to redirect energy to foliage. Can allow flowering for seed production.

5

Maturity

6-12 months or more

Established plant with woody base and extensive branching; leaves remain harvestable for extended periods in ideal conditions.

Plant can produce for 6-12 months in frost-free climates. Rejuvenate by cutting back hard (to 6-12 inches) to stimulate new growth. Replace plants annually or every 2 years.

Companion Planting

Plan your garden →

Plant with:

Basil Okra Sweet potato Eggplant Beans Corn Tomato

Avoid planting near:

Fennel Brassicas (cabbage, broccoli) - compete for nutrients Heavy feeders in poor soil conditions

Common Pests

  • Spray with neem oil or insecticidal soap; increase air circulation; use yellow sticky traps; release beneficial parasitic wasps

  • Increase humidity through misting; spray with water to dislodge; use neem oil if severe; introduce predatory mites

  • Spray with strong water stream; apply neem oil or insecticidal soap; encourage natural predators like ladybugs and lacewings

  • and

    Hand-pick visible larvae; apply Bt (Bacillus thuringiensis); use neem oil spray

  • and

    Remove by hand at dusk; create barriers with diatomaceous earth or copper tape; provide ground covers to remove hiding spots

Uses

🍳

Nutritious Leafy Green

Culinary

Okinawan spinach is used fresh in salads, stir-fries, soups, and as a cooked green similar to spinach. It has a mild, slightly sweet flavor and tender texture when young. High in vitamins A, C, and minerals, it's a staple in Okinawan and Southeast Asian cuisine. [source]

🍳

Heat-Tolerant Spinach Substitute

Culinary

Unlike traditional spinach which bolts in hot weather, Okinawan spinach thrives in tropical and subtropical climates, making it ideal for warm-season cooking. It serves as a perfect replacement in recipes requiring tender greens during summer months. [source]

💊

Traditional Wellness Use

Medicinal

In traditional Okinawan and Chinese medicine, Alternanthera sissoo is used as a cooling herb and is believed to have detoxifying properties. Modern nutritional analysis confirms its high content of vitamins, minerals, and antioxidants. [source]

🏠

Container and Ornamental Growing

Household

Beyond food production, Okinawan spinach works as an attractive ornamental plant for tropical gardens and containers. Its trailing habit and heart-shaped leaves make it aesthetically pleasing while providing functional food production. [source]

🦋

Pollinator-Friendly Plant

Wildlife

The flowers attract bees and other pollinators, supporting beneficial insect populations in the garden. Growing Okinawan spinach contributes to a diverse, pollinator-friendly ecosystem. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Begin harvesting outer leaves when plant is 6-8 inches tall, typically 30-50 days after planting. Pinch or cut leaf clusters from the top and sides to encourage bushier growth. Harvest regularly (2-3 times weekly in peak season) to maintain tenderness and productivity. Mature leaves become tougher and more bitter; young tips are most palatable. Plants grown in containers or cooler climates may produce for 3-6 months; tropical climates allow year-round harvest.

Fun Facts

  • 🌱 Okinawan spinach is one of the primary leafy greens in the traditional Okinawan diet, which is celebrated for its role in the longevity and health of Okinawan people.
  • 🌱 Unlike common spinach (Spinacia oleracea), which requires cool seasons, Okinawan spinach actually improves in flavor and productivity during hot, humid weather, making it superior for tropical gardening.
  • 🌱 The plant is also known as water spinach's cousin and can tolerate similar growing conditions, though it's distinct in flavor and texture, offering gardeners more versatility in warm climates.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Annual Deadhead Full Sun Partial Shade pH Pinch Back Trellis True Leaves
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