Java ferns are one of the most popular aquatic plants in home aquariums. With their hardy nature and undemanding growing requirements, java ferns are almost foolproof to keep alive underwater. But what happens when you take them out of their aquatic environment? Can java ferns adapt to grow and thrive above water as well?
The short answer is yes! Java ferns are incredibly versatile plants that can flourish when grown partially or fully emerged from water. While they naturally grow submerged, they can adapt to environments with high humidity and moist roots. With the right care, java ferns can become a uniquely beautiful addition to potted plant collections or terrarium landscapes.
This comprehensive guide will explore everything you need to know about growing java ferns out of water. We’ll look at their background, versatility as a species, and best practices for helping them thrive above the waterline. Learn more about successfully growing these adaptable aquarium plants in a new environment!
The Versatility of Java Ferns
Java ferns (scientific name: Microsorum pteropus) originate from tropical parts of Southeast Asia. Here they grow as epiphytes, meaning they attach themselves to other structures like rocks or trees rather than rooting in soil.
In the wild, they thrive in warm, humid conditions in partially shaded areas along river banks and other wet environments. Although submerged growth is typical, wild java ferns often grow emersed during dry seasons when water levels drop.
This natural resilience allows them to adapt to varied growing conditions in home aquariums and terrariums. Java ferns are not demanding about water quality, lighting, or substrate. They can grow fully aquatic, partially submerged, or completely above water with the right care.
Key Takeaways:
- Java ferns originate from tropical Southeast Asia where they grow as epiphytes.
- They are adaptable plants that grow submerged, partially emerged, or fully above water.
- This versatility makes them popular for aquariums and terrariums.
Does Java Fern Need to Be Fully Submerged?
Many aquarists assume java ferns require permanent submersion to survive. But that’s not the case – java ferns can adapt well to partially or fully emerged set-ups.
In the wild, java ferns thrive along river banks in humid, shady areas. Although typically submerged, natural water level fluctuations mean they often emerge for periods. They are well adapted to both environments.
You can recreate these conditions at home. Some leaves can grow above water as long as the rhizome stays moist. Over time, the plant will adapt by producing more compact growth better suited to the emerged habitat.
Java fern’s versatility gives aquarists more options. You can allow some leaves to breach the surface in open-top aquarium designs. And fully emerged growth creates a tropical feel in paludariums and ripariums.
Key Takeaways:
- Java ferns do not need to be kept permanently underwater.
- Natural habitat fluctuations mean they readily adapt to partial or full emersion.
- The rhizome must stay moist, but leaves can grow above water.
How Long Can Java Fern Live Without Water?
Java ferns are dependent on constant access to water to survive long-term. But the rhizome and roots have some capacity to endure short periods of dryness.
Rhizome
The rhizome is the horizontal, thick green stem that anchors the plant. It stores nutrients and must remain moist at all times. The rhizome will dry out and die after 24-48 hours without moisture.
Roots
The fuzzy roots that grow from the rhizome have a bit more tolerance for dryness. If the rhizome stays wet, exposed roots can survive several days without water. But they will eventually wither and rot without moisture.
Fronds
The leafy fronds are more resilient than the rhizome or roots. Dry fronds may yellow but can recover once water is restored. But long-term survival depends on the rhizome staying hydrated.
Key Takeaways:
- Java ferns depend on constant moisture, especially at the rhizome.
- Fronds can temporarily tolerate dryness better than the rhizome and roots.
- The rhizome will die after 24-48 hours without water.
How to Grow Java Ferns Outside the Water
Growing java fern out of water is certainly possible, but does require some adaptations to care. Here are some tips to help your java ferns thrive above the waterline:
Select a Suitable Growing Surface
Java ferns attach to solid surfaces through their rhizome and roots. When keeping them emerged, make sure to offer an appropriate attachment site. Good options include:
- Driftwood – Mimics natural habitat on tree branches. Offers plenty of crevices for anchoring.
- Rocks – Provides a sturdy base. Choose porous rocks that retain some moisture.
- Plastic mesh – Synthetic mesh gives roots something to cling to. Use plastic or stainless steel.
Avoid direct soil planting, as this will cause rhizome rot over time. An open, non-soil setup is best.
Keep the Rhizome Wet
Constant moisture at the rhizome is critical for java ferns grown emersed. Use a few techniques to accomplish this:
- Partial submersion – Allow part of the rhizome to sit underwater.
- Misting – Regularly mist the rhizome 1-2 times per day.
- Wicking – Place the base of the attachment surface in water to wick moisture upwards.
Monitor moisture levels daily. Add water immediately if the rhizome ever dries out.
Ensure High Humidity
Java ferns prefer humid conditions around 70-100% relative humidity. Consider these options:
- Cover open-top set-ups with glass or acrylic lids to contain moisture.
- Use an aquarium or terrarium to keep java ferns in a humid enclosed space.
- Place porous rocks around the base to slow moisture loss via evaporation.
Use a hygrometer to monitor humidity, maintaining levels above 60% minimum.
Provide Bright, Indirect Light
Java ferns prefer shaded conditions when grown emerged. Place them under overhangs or floating plants to filter light. If needed, attach them lower on the growing surface away from intense light near the water surface.
Grow Slowly
Growth above water occurs at a slower pace. Be patient and allow several weeks for the plant to acclimate fully. Remove any dried fronds to focus energy on new adapted growth.
With the right conditions, java ferns will adapt by producing shorter, more compact fronds better suited to aerial growth.
Monitor for Pests
Emerged plants are more prone to pests like snails and algae. Remove or treat any infestations immediately to avoid damaging the vulnerable rhizome.
Key Tips for Growing Java Fern Emersed:
- Provide wet rhizome and high humidity.
- Give bright, indirect light.
- Allow time to adapt growth slowly.
- Attach to driftwood, rocks or plastic mesh.
- Keep away pests and algae.
Java Fern Diseases and Pests
Java ferns are hardy plants, but they can encounter problems when grown emerged or fully aquatic. Know how to recognize and treat these potential issues:
Diseases
Rhizome Rot
Caused by persistent moisture on the rhizome, bacterial or fungal rot appears as brown, mushy decay. Improve air circulation and treat with anti-fungal medications. Prune off any rotten portions.
Leaf Spot Algae
Small black dots that appear on the leaves. Caused by fluctuations in carbon levels. Manually remove affected leaves and improve water movement.
Fungal Infections
Fungus can attack leaves and rhizomes in humid conditions. Typically occurs if dying plant matter is left attached. Improve air flow and prune off infected parts. Treat with anti-fungal chemicals as needed.
Pests
Snails
Slugs and snails will feed on both leaves and tender rhizomes. Remove them manually and use traps or chemical treatments if needed.
Aphids
Tiny sap-sucking insects that cluster on leaves. Rinse off with water or use horticultural oils or insecticidal soaps.
Mealybugs
Small cottony insects that leave white deposits on foliage. Wipe away manually and apply insecticidal soap.
Thrips
Tiny flying insects that pierce and feed on leaves. Use sticky traps and insecticide sprays if infestations are severe.
Prompt identification and treatment of diseases and pests is key. Maintain clean water and use quarantine periods for new plants.
Other Aquarium Plants That Can Be Grown Out of Water
Java ferns are not the only aquatic plants suitable for above-water growth. Many aquarium species can adapt to emersed set-ups if care requirements are met. Here are some top choices:
Anubias
Anubias offer thick, waxy leaves that retain moisture well. They come in several varieties like Anubias barteri and Anubias nana. Slow growing, they do best attached to driftwood or rocks partially submerged.
Bucephalandra
These tropical Asian plants have intriguing leaves in a variety of shapes. They grow slowly, but Bucephalandra motleyana and Bucephalandra lamandau adapt well to emersed culture.
Cryptocorynes
Several Cryptocoryne species work above water, including Cryptocoryne wendtii and Cryptocoryne beckettii. Plant in pots with a very wet soil mix and provide tropical temperatures.
Mosses
Aquarium mosses like Java moss (Taxiphyllum barbieri) and Christmas moss (Vesicularia montagnei) thrive in humid terrarium conditions. Attach to driftwood or rocks and keep the substrate moist.
Sword Plants
Select species like Echinodorus angustifolia produce shorter leaves with lower moisture needs, perfect for above-water growth. Plant in pots with wet substrate and bright light.
Many marginal pond plants can also adapt to hydroculture emersed growth. Spider lilies, umbrella palms, and papyrus sedge are examples. With some trial and error, you can find many suitable candidates.
Common Java Fern Growing Problems
Java ferns are not difficult plants, but they can encounter issues if care conditions are not ideal. Here are some potential problems and how to fix them:
Yellow or Browning Leaves
This can occur with too much light or if the rhizome dries out. Move to shadier spot and ensure the rhizome stays moist. Remove any rotted roots and replace water.
Slow Growth
Low light, low nutrients, or cool temperatures can slow growth. Increase light intensity, fertilize sparingly, and provide temperatures above 70°F.
Leggy Growth
If fronds become elongated and sparse, it is reaching for more light. Prune leggy parts and reposition in a brighter location.
Melting Leaves
Sudden leaf melt is often due to rapid parameter changes, like pH or temperature shifts. Make adjustments slowly and improve water stability.
Holes in Leaves
Holes and notches on leaf edges indicates pest damage. Remove snails/slugs. Treat for deficiencies that make plants more vulnerable.
Blackened Roots
A sign of root rot from polluted water lacking oxygen circulation. Improve water flow and filtration. Trim off dead roots and treat with anti-fungal medication.
Key Takeaways on Java Fern Problems:
- Ensure adequate but indirect light and nutrients.
- Maintain stable water conditions and ideal temperatures.
- Watch for pests, diseases, or drying rhizomes.
- Make adjustments slowly and remove damaged tissue.
Conclusion
Java ferns are a versatile aquatic plant that can adapt to fully or partially emerged growth. By mimicking their natural habitat with a wet rhizome, high humidity, warm temperatures, and indirect light, java ferns can thrive above the waterline. Best practices include:
- Providing a solid attachment site like driftwood that can be partially submerged.
- Keeping the rhizome constantly wet through misting, wicking, and partial immersion.
- Ensuring sufficient air circulation and humidity.
- Allowing time for slow acclimation to aerial conditions.
- Looking out for potential pest and disease issues.
While they cannot survive long-term completely dry, their ability to grow immersed, submerged, or emerged makes java ferns a great choice for paludariums and ripariums. Their lush green foliage adds a wonderfully tropical feel. With extra care, java ferns can broaden their reach beyond aquascaping to become a uniquely adaptable indoor plant.
