How to Grow Okinawan Amaranth

Wikimedia Commons

Okinawan Amaranth

Amaranthus tricolor

vegetable

Okinawan Amaranth is a leafy green vegetable with distinctive reddish-purple stems and veins running through tender green leaves, offering both nutritional value and ornamental appeal. Native to tropical regions, it thrives in warm climates and is prized in Asian cuisine for its tender leaves and edible stems. The plant is highly nutritious, rich in vitamins, minerals, and protein.

When should you plant Okinawan Amaranth in your zone?

Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.

Get my Okinawan Amaranth timeline →

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

  1. Plant Okinawan Amaranth

    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 Amaranth

    Around May 27

    ≈ 40 days after planting

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

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily; tolerates partial shade in very hot climates
💧
Water: Keep soil consistently moist but not waterlogged; water deeply 2-3 times per week; more frequent watering in hot weather; mulch to retain moisture
📏
Spacing: 8-12 inches
📅
Days to maturity: 40-60 days to first harvest; continuous harvest possible
🌱
Planting depth: 0.25-0.5 inches; seeds are tiny and should be barely covered

Soil

Type: Well-draining, fertile loamy soil rich in organic matter
pH: 6.0-7.0
Amendments:
Compost Well-rotted manure Aged leaf mold Balanced fertilizer (10-10-10)

Growing Zones

Find your zone →

Thrives in zones 9b-11; can be grown as an annual in cooler zones (8-9a) during warm months

9b 10a 10b 11a 11b

Sign up free to see if Okinawan Amaranth grows in your zone — and get a personalized planting timeline.

Get my Okinawan Amaranth timeline →

Growth Stages

1

Seedling

2-3 weeks

Tiny cotyledons emerge; true leaves appear within 1-2 weeks with characteristic red/purple coloring beginning to show

Keep soil warm (70-85°F); maintain consistent moisture; thin seedlings to proper spacing when 2-3 inches tall; provide bright light

2

Vegetative Growth

3-4 weeks

Plant develops multiple stems with increasingly prominent red/purple veining in green leaves; bushy growth habit; leaves become larger and more tender

Water regularly; begin light harvesting of outer leaves to encourage bushiness; apply balanced fertilizer every 2-3 weeks; pinch growing tips to promote branching

3

Leaf Production Peak

4-6 weeks

Plant reaches optimal foliage density with vibrant red-veined green leaves at peak tenderness; stems are succulent and flavorful

Harvest frequently to encourage continued leaf production; maintain consistent moisture; feed with nitrogen-rich fertilizer; remove any flowering shoots to prolong vegetative growth

4

Flowering

Ongoing if not managed

Small inconspicuous flowers appear in terminal spikes; plant begins to focus energy on seed production rather than leaf quality

Pinch off flower buds to extend harvest period; if allowing flowering for seed saving, reduce nitrogen fertilizer; harvest leaves before flowering for best quality

5

Seed Maturation

2-3 weeks

Flowers develop into seed heads containing tiny black seeds; leaves become tougher and less palatable

Allow to dry if saving seeds; harvest seeds when heads are fully dry; typically not harvested for consumption at this stage

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Fennel Cabbage Broccoli Cauliflower Spinach Chard

Common Pests

  • Handpick on young plants; use Bacillus thuringiensis (Bt) spray; encourage natural predators like parasitic wasps; maintain clean garden beds

  • Spray with water to dislodge; use neem oil; maintain humidity above 60%; prune heavily infested leaves; encourage predatory mites

  • Use row covers on young plants; apply neem oil or insecticidal soap; plant trap crops; encourage ground beetles

  • Use yellow sticky traps; spray with insecticidal soap; apply neem oil; encourage parasitic wasps; avoid excessive nitrogen

  • Spray with water to dislodge; apply insecticidal soap; use neem oil; introduce ladybugs or lacewings; plant aromatic herbs nearby

Uses

🍳

Stir-fries and Asian dishes

Culinary

Tender leaves and succulent stems are commonly used in Southeast Asian cuisine, particularly Okinawan cooking. The mild, slightly sweet flavor works well in quick-cooking methods. [source]

🍳

Nutritious salads and raw applications

Culinary

Young, tender leaves can be used raw in salads, offering a mild flavor and crispy texture. Larger leaves are better cooked but can be massaged for raw applications. [source]

💊

Traditional health benefits

Medicinal

In traditional Okinawan and Asian medicine, amaranth greens have been used to support overall wellness and provide high levels of bioavailable nutrients including iron, calcium, and vitamin A. [source]

🍳

Soups and braised dishes

Culinary

Mature leaves and stems hold up well to cooking and add nutrition and color to soups, stews, and braised vegetable dishes. The red pigments create visually appealing presentations. [source]

🏠

Ornamental garden element

Household

The striking red-veined foliage makes Okinawan Amaranth an attractive addition to ornamental gardens while still providing an edible harvest, combining aesthetics with function. [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 (about 30-40 days); pinch off tender top 2-3 inches of stems and young leaves; harvest frequently to encourage continued production and prevent flowering; best harvested in early morning when leaves are crisp and full of moisture; leaves are most tender and flavorful when young; can continue harvesting for 8-12 weeks in favorable conditions

Fun Facts

  • 🌱 Okinawan Amaranth has been a dietary staple in Okinawa for centuries, contributing to the region's reputation for longevity and exceptional health outcomes.
  • 🌱 The red/purple coloration in the leaves and stems comes from betalain pigments, powerful antioxidants that are also found in beets and provide significant health benefits.
  • 🌱 Amaranth is a complete protein source, containing all nine essential amino acids, making it particularly valuable in vegetarian and vegan diets.

Gardening Terms

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

Join 30,000 gardeners planning their gardens with LizPlants.

Get your personalized Okinawan Amaranth planting timeline

Tell us your zip code and we'll calculate exactly when to start Okinawan Amaranth seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.

Get my Okinawan Amaranth timeline →