How to Grow Aquatic Amaranth
Aquatic Amaranth
Alternanthera philoxeroides
vegetableAquatic amaranth is a semi-aquatic plant with succulent stems and small oval leaves that grows in shallow water or marshy conditions. It is widely cultivated in Southeast Asia, particularly Vietnam and Cambodia, as a nutritious leafy green vegetable. The tender shoots and leaves are harvested and consumed fresh or cooked in soups and stir-fries.
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Example Aquatic Amaranth timeline · Pittsburgh, PA (Zone 6b)
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Plant Aquatic Amaranth
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Aquatic Amaranth
Around May 17≈ 30 days after planting
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Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in warm tropical and subtropical zones (9b-11b). Grows best in temperatures above 70°F (21°C).
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Get my Aquatic Amaranth timeline →Growth Stages
Establishment
1-2 weeksNewly planted cuttings or seedlings develop roots and initial leaf growth in water or saturated soil.
Ensure consistent moisture and water temperatures of 70-85°F. Protect from strong currents if in water. Reduce light stress by maintaining stable conditions.
Vegetative Growth
2-3 weeksPlant produces multiple stems with increasingly larger oval leaves. Vigorous foliage development occurs as stems elongate.
Apply aquatic or balanced fertilizer every 2-3 weeks. Thin crowded areas to improve airflow. Maintain water level consistent with plant height.
Shoot Development
1-2 weeksYoung tender shoots emerge from leaf axils and stem tips, creating harvestable leafy growth.
Begin light harvesting of outer shoots to encourage bushier growth. Continue regular fertilization. Monitor for pest colonization on new growth.
Harvesting & Maintenance
Ongoing, 6-8+ weeksPlant reaches harvestable size with abundant tender shoots and leaves ready for cutting.
Harvest regularly (every 7-10 days) to maintain tenderness and encourage new shoot production. Remove any yellowing or damaged leaves. Continue fertilization.
Maturity & Decline
Variable, typically 8-12 weeks total before renewalIn cooler seasons or as plant ages, growth slows, stems become woody, and leaves may yellow or drop.
Cut back severely or replant with fresh cuttings. In tropical climates, can persist year-round with renewal pruning. Discard if disease appears.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Spray with water to dislodge; use neem oil or insecticidal soap in early morning. Remove heavily infested leaves.
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Yellow sticky traps to monitor and control. Spray undersides of leaves with neem oil or insecticidal soap. Improve air circulation.
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Hand-pick early morning or evening. Remove debris where they hide. Use copper barriers around planting area. Beer traps in containers.
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Mist foliage regularly to increase humidity. Use neem oil or sulfur spray. Remove heavily infested leaves.
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Remove infected leaves promptly. Improve air circulation and reduce leaf wetness duration. Apply copper fungicide if severe. Avoid overhead watering in afternoons.
Uses
Stir-fries and soups
CulinaryThe tender leaves and shoots are commonly prepared in Southeast Asian cuisine, particularly in Vietnamese and Cambodian dishes. They are sautéed, stir-fried, or added to soups and broths, offering a slightly succulent texture and mild, slightly nutty flavor. [source]
Fresh salads and side dishes
CulinaryYoung leaves can be eaten raw in salads or served as a fresh steamed side dish. They provide a tender, mild leafy green with a crisp texture similar to spinach or water spinach. [source]
Traditional herbal medicine
MedicinalIn traditional Chinese and Southeast Asian medicine, aquatic amaranth is used to treat inflammation, fever, and digestive complaints. It is believed to have cooling and detoxifying properties. [source]
Aquaponics and aquatic gardening
HouseholdExcellent for aquaponic systems and ornamental water gardens. It oxygenates water, filters excess nutrients produced by fish, and grows rapidly in hydroponic or semi-aquatic conditions. [source]
Fish and aquatic habitat
WildlifeProvides shelter and foraging habitat for small fish and aquatic invertebrates in pond systems. Can be part of constructed wetlands for water filtration and ecosystem support. [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 tender shoots and leaves 30-45 days after planting. Pinch or cut the top 3-6 inches of stems regularly to encourage bushier growth and maintain tenderness. Harvest in early morning for crispest leaves. Can harvest continuously every 7-10 days by removing outer shoots, leaving the central growth point intact. Use scissors or pinch with fingers. Young leaves are most tender and mild; older leaves become tougher. Best harvested when 4-6 inches long.
Fun Facts
- 🌱 Aquatic amaranth is native to South America but has become naturalized and is a major commercial vegetable crop in Vietnam, where it is called 'rau dền nước' and is exported globally.
- 🌱 The plant can reproduce through both seeds and stem fragments, spreading rapidly in warm, wet conditions—so much so that it is considered invasive in some non-native regions.
- 🌱 Unlike terrestrial amaranth, aquatic amaranth thrives in waterlogged conditions and is often grown in flooded paddies or on the margins of fish ponds, making it an ideal companion to aquaculture systems.
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