How to Grow Red Edge
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Red Edge
Alternanthera reineckii
herbRed Edge is a striking aquatic or semi-aquatic plant known for its vibrant red and pink foliage that intensifies with bright light. It's commonly grown in aquariums and paludariums as a decorative stem plant. While it can survive in moist terrestrial conditions, it thrives best in aquatic environments.
When should you plant Red Edge in your zone?
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Example Red Edge timeline · Pittsburgh, PA (Zone 6b)
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Plant Red Edge
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 Red Edge
Around May 17≈ 30 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Red Edge dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 10b-11, grown as houseplant in cooler climates or in aquariums year-round
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Planting & Acclimation
1-2 weeksFresh stem cuttings or young plantlets with minimal root development; leaves may appear pale green to light red
Provide stable water conditions, gentle flow, and consistent lighting. Avoid direct strong currents immediately after planting. Mist if growing terrestrially.
Root Development
2-4 weeksNew root nodules form along the buried stem; existing leaves stabilize in color
Apply liquid fertilizer weekly; ensure good water circulation. Increase light intensity gradually to encourage rooting without shocking plant
Vegetative Growth
3-8 weeksNew leaves emerge with increasingly vibrant red and pink hues; stems elongate rapidly
Maintain high light (10+ hours daily) to maximize red coloration. Dose fertilizers regularly—macro and micronutrients essential. Prune tall stems to encourage branching
Mature Specimen
Ongoing, 2+ monthsFull-grown plant with dense red foliage; may reach 12+ inches tall; occasionally produces small cream/white flowers in terrestrial conditions
Continue consistent lighting and fertilization. Prune regularly to maintain shape and encourage bushier growth. Do not allow algae to cover leaves
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Reduce light duration if algae blooms occur; increase water change frequency; use algae-eating fish or shrimp; manually remove visible algae; avoid overfeeding fish
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Hand-remove if excessive; introduce snail-eating fish like pufferfish or loaches; or use snail-specific treatments; quarantine new plants to prevent introduction
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Increase humidity; spray with neem oil solution; isolate affected plants; improve air circulation
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Improve water circulation and quality; reduce decaying organic matter; increase water change frequency; remove affected leaves; maintain stable temperature
Uses
Aquarium Decoration
HouseholdRed Edge is prized in planted aquariums and aquascaping for its stunning red and pink foliage that creates visual contrast and depth. It's popular in Nature-style and Iwagumi aquascapes. [source]
Terrarium & Paludarium Feature
HouseholdThrives in moist terrariums and paludariums (aquatic-terrestrial hybrid setups) where high humidity levels support both aquatic and land growth. Often used as a mid-ground or background plant. [source]
Fish Habitat & Spawning Medium
WildlifeProvides shelter and hiding places for small fish species and aquatic shrimp. Dense plant growth offers spawning substrate for egg-scattering and mouth-brooding fish species. [source]
Indoor Living Decor
HouseholdCan be grown in high-humidity terrariums or glass enclosures on a windowsill as a striking indoor houseplant, offering ornamental value year-round in temperate climates. [source]
Ornamental Phytoremediation
MedicinalLike many aquatic plants, Red Edge helps reduce excess nutrients (nitrogen, phosphorus) in aquarium water, contributing to a healthier aquatic ecosystem and supporting overall plant health. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Red Edge is not harvested for consumption or yield. Instead, propagate by taking 2-4 inch stem cuttings and replanting them in substrate. Cuttings root readily within 2-3 weeks. Prune regularly (every 2-4 weeks) to maintain compact shape and encourage fuller, bushier growth. Remove lower leaves before planting cuttings to prevent rot.
Fun Facts
- 🌱 Red Edge's vibrant coloration is a direct result of high light exposure—the red pigment (anthocyanin) acts as a sunscreen protecting the leaf from excess light, making it a 'light indicator' plant that shows aquarists when lighting is optimal.
- 🌱 Unlike many aquatic stem plants, Red Edge can be grown either fully submerged in water or emersed (partially out of water) in paludariums, though it typically grows more compact and colorful when fully submerged.
- 🌱 The plant is native to South America (Brazil and Paraguay regions) and is sometimes sold under the names 'Bloodleaf,' 'Red Alternanthera,' or 'Scarlet Temple' in the aquarium hobby.
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