How to Grow Carmine Red Alternanthera

Carmine Red Alternanthera

Alternanthera reineckii 'Carmine Red'

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Alternanthera reineckii 'Carmine Red' is a vibrant aquatic/terrarium plant featuring deep burgundy-red undersides and olive-green upper leaf surfaces that intensify to striking carmine-red coloring under high light. This compact, bushy cultivar is prized in aquascaping for its dramatic foliage contrast and is equally suitable for humid terrariums and wet outdoor gardens. It grows slowly to moderately and maintains an attractive columnar shape with minimal pruning.

Growing Conditions

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Sun: High light: 8-10+ hours daily for optimal red coloration; moderate light (4-6 hours) acceptable but produces less vibrant color

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Water: Aquatic form: fully submerged or emersed in consistently moist conditions; terrarium form: high humidity (70-80%) with consistently wet to moist soil; avoid waterlogging terrestrial specimens

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Spacing: 4-6 inches apart (allows room for lateral branching) inches

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Days to maturity: 60-90 days to full coloration and established growth

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Planting depth: Plant stems with at least 2-3 nodes buried; in aquariums, use stem weights or plant directly into substrate 1-2 inches deep

Soil

Type: Nutrient-rich aquatic substrate (aquariums) or well-draining, humus-rich soil (terrestrial)

pH: 6.0-7.5

Amendments:

Root tabs or aquatic fertilizer pellets Peat moss or coconut coir Activated carbon in aquarium settings Iron-rich aquatic fertilizers for color intensity

Growing Zones

Find your zone →

Zones 10b-11; typically grown indoors or as an annual in cooler climates

10b 11a 11b

Growth Stages

Propagation & Establishment

2-4 weeks

Newly planted stem cuttings or rooted plants show pale or olive foliage; root development occurs over 2-3 weeks

Keep in stable conditions with moderate lighting; avoid excessive current or disturbance; apply liquid fertilizers weekly

Vegetative Growth

4-8 weeks

Stems develop multiple lateral branches; foliage gradually intensifies in color; plant fills out horizontally

Increase lighting gradually to encourage red coloration; provide macronutrients (NPK) and micronutrients (iron, boron, manganese); pinch stems to promote bushiness

Full Color Development

Ongoing once established

Undersides and new growth display deep carmine-red pigmentation; leaves remain firm and vibrant; plant reaches mature bushy form

Maintain high light (8-10 hours), stable water parameters (aquatic) or humidity (terrarium), and consistent fertilization; prune to maintain shape

Maturation & Maintenance

Indefinite with proper care

Plant reaches full size; colors fully saturated; may produce small, inconspicuous flowers in emersed form (terrestrial settings)

Maintain regular feeding schedule; trim runners and lower stems to promote dense, compact growth; monitor for algae competition

Companion Planting

Plan your garden →

Plant with:

Ludwigia repens Rotala rotundifolia Hemianthus callitrichoides (Dwarf Baby Tears) Anubias Cryptocoryne Echinodorus (Amazon sword) Moss species (Java, Christmas, Flame)

Avoid planting near:

Allelopathic plants (none specific to Alternanthera, but avoid dense shading from aggressive stem plants) Plants requiring very cool water temperatures (incompatible in same tank)

Common Pests

Reduce lighting duration if excessive; increase water changes; introduce algae-eating fish (Siamese flying fox, otocinclus); use Excel or hydrogen peroxide treatments (aquatic only)
Increase humidity; spray foliage with water; apply neem oil or insecticidal soap in non-aquatic terrariums
Apply comprehensive aquatic or hydroponic fertilizer; use chelated iron supplements; dose according to plant mass and light intensity
and (terrestrial)
Improve air circulation; reduce humidity temporarily; remove affected leaves; apply fungicide if severe

Uses

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Aquascaping & Aquarium Décor

Household

Carmine Red Alternanthera is a premium choice for freshwater planted aquariums, adding dramatic burgundy and red tones to aquatic hardscaping designs. Its compact growth habit and stunning bicolor foliage make it ideal for midground placement in Dutch-style and nature aquarium layouts. [source]

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Terrarium & Paludarium Feature Plant

Household

Thrives in humid terrarium and paludarium environments where it displays emersed (emergent) growth and vivid coloration. Suitable for both glass terrariums and open-topped wet plant containers. [source]

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Color Contrast & Design Element

Craft

The striking red-undersides-green-tops bicolor foliage creates dramatic visual contrast in planted tank scaping, making it a popular choice for competitive aquascaping competitions and high-end display tanks. [source]

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Aquatic Habitat & Fish Shelter

Wildlife

Provides dense branching structure that offers shelter and grazing surfaces for aquatic shrimp, small fish fry, and microorganisms, supporting a more naturalistic aquatic ecosystem. [source]

Harvest Tips

Not typically harvested for consumption. For propagation: Cut 2-3 inch stem sections with at least 2 nodes; remove lower leaves and plant in substrate or float in water until roots develop (7-14 days); replant rooted cuttings. Prune upper stems to encourage bushier growth and maintain color intensity.

Fun Facts

🌱 The intense red coloration (from anthocyanin pigments) intensifies dramatically under high-intensity lighting and is often deeper in aquatic/submerged form than terrestrial growth, making lighting a key factor for maximum visual impact.
🌱 Alternanthera reineckii is native to South America (primarily Paraguay and Argentina) and was first cultivated in European aquariums in the early 2000s, becoming one of the most popular red stem plants in the hobby.
🌱 The 'Carmine Red' cultivar was developed through selective breeding to emphasize the red undersides, distinguishing it from the wild-type which displays less saturated colors.

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