How to Grow Floating Fern
iNaturalist
Floating Fern
Ceratopteris cornuta
fernCeratopteris cornuta is a delicate aquatic fern with feathery, finely divided fronds that can either float on water surfaces or root in substrate. This tropical fern is popular in aquariums and water gardens for its ethereal appearance and rapid growth. It thrives in warm, nutrient-rich water environments and is valued by aquarium enthusiasts for its ability to absorb excess nutrients and provide shelter for small aquatic creatures.
When should you plant Floating Fern 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.
Example Floating Fern timeline · Pittsburgh, PA (Zone 6b)
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Plant Floating Fern
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 Floating Fern
Around May 17≈ 30 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Floating Fern dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Zones 10b-11 outdoors; indoor cultivation year-round in cooler climates
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Get my Floating Fern timeline →Growth Stages
Spore/Propagule
1-2 weeksFern begins from spores or vegetative propagules; initial roots and frond emergence
Maintain warm water (75-80°F), stable conditions, and gentle water movement; ensure adequate nutrients
Juvenile Growth
2-4 weeksYoung fronds unfurl with characteristic feathery, lacy appearance; plant grows rapidly
Provide bright light and balanced liquid fertilizer; monitor water quality and temperature consistency
Established
Ongoing (weeks 5+)Plant develops multiple mature fronds with full lacy division; reaches typical growth form
Continue regular fertilization and water changes; thin overcrowded growth to prevent shading lower fronds
Reproduction
Variable, typically 6+ weeksPlant produces plantlets vegetatively along frond margins or at base; spore production may occur
Allow runners and plantlets to develop; can be separated and propagated independently
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Remove manually; use copper-free snail control if needed; introduce natural predators like assassin snails
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Reduce light duration; increase water changes; introduce algae-eating fish or shrimp; use algaecide if necessary
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Quarantine affected plants; increase humidity and misting if terrestrial culture; use miticide carefully in aquatic settings
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Keep plant away from goldfish, plecos, and other vegetarian fish; use plant guards if necessary
Uses
Aquarium Plant & Water Purification
HouseholdCeratopteris cornuta rapidly absorbs excess nutrients (nitrogen, phosphorus) from aquarium water, helping to reduce algae growth and improve water quality. Its dense fronds provide shelter and surfaces for beneficial bacteria colonization. [source]
Fish & Aquatic Creature Habitat
WildlifeThe finely divided, delicate fronds create ideal hiding spaces and grazing surfaces for small fish fry, shrimp, and invertebrates. The plant also serves as a food source and nursery for aquatic fauna. [source]
Aquascaping & Aquarium Aesthetics
HouseholdThe ethereal, feathery appearance of Ceratopteris cornuta adds natural beauty and aesthetic depth to aquariums and water gardens. Its rapid growth allows for creative design and easy manipulation of aquatic layouts. [source]
Traditional Herbal Use
MedicinalIn Southeast Asian traditional medicine, Ceratopteris species have been used to treat various ailments including inflammation and fever. The fern contains bioactive compounds studied for potential medicinal properties. [source]
Edible Aquatic Vegetable
CulinaryIn Southeast Asia, young fronds and growing tips of Ceratopteris cornuta are consumed as a nutritious vegetable, rich in vitamins and minerals. The tender fronds can be lightly cooked or added to salads. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
This fern is not harvested for consumption. For propagation, remove and relocate plantlets when they develop roots and are 1-2 inches long. Trim excess or damaged fronds to encourage new growth. Harvesting is performed to manage plant density and shape in aquariums rather than for culinary or medicinal purposes.
Fun Facts
- 🌱 Ceratopteris cornuta can reproduce both sexually (via spores) and asexually (via vegetative plantlets), making it one of the fastest-growing aquatic ferns in the hobby.
- 🌱 This fern is sometimes called a 'water sprite' and is a staple in planted aquariums because it can adapt to both rooted and free-floating lifestyles depending on water conditions and aquarium design.
- 🌱 The species is native to tropical regions of South America and Asia, where it naturally colonizes wetlands, slow-moving streams, and flooded areas, thriving in warm, nutrient-rich waters.
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