Java Fern – Narrow Leaf

Description

Our favourite plant! The Java fern is a uniquely magnificent, slow-growing, and beautiful plant. This is a rhizome plant (that has a horizontal “stem”), which propagates by growing its rhizome out while creating new leaves, or by generating baby plantlets through the leaf itself! A truly interesting plant.

Originating from Southeast Asia, this hardy plant adds natural beauty, oxygenation, and shelter for fish. Its elegant, undulating fronds make it an excellent choice for both planted and bare-bottomed aquariums.

Characteristics

• Long, narrow, dark green leaves that grow up to 12 inches in length.
• The rhizome should be buried while the roots hang down into the water column.
• Can thrive either attached to decorations or free-floating using its unique root structure.

Care

Java Fern – Narrow Leaf is known for its adaptability and ease of maintenance. It prefers low to medium lighting conditions. Avoiding intense, direct light is recommended to prevent algae growth and leaf damage. This fern is not demanding regarding CO2 and can flourish without additional supplementation, although CO2 injection can lead to better or denser growth. While nutrient requirements are minimal and it can take nutrients from the water column (including fish waste), it can benefit from occasional fertilization. Crucially, the rhizome should not be buried in the substrate, as this can cause it to rot. It should be attached to hardscape such as driftwood or rocks until the roots can anchor themselves. It can also be grown floating but it will eventually find a place to attach to.

Placement

The most common placement method is to attach this plant on to hard objects such as lava rocks or driftwood, as this is how it does best in nature. The roots will slowly cling to whatever object is nearby, whether it be gravel, rocks, or wood.

In order to attach the Java fern onto objects, the best way is to use cotton thread or super glue. The thread or super glue will slowly dissolve as the plant grows and the roots start attaching to the object.

The rhizome (horizontal green stem) of this plant must be above the substrate and not buried. It is important to note that the rhizome needs light and access to CO2 and oxygen from the water column just as the leaves do.

Interestingly enough, this plant will also thrive when emerged (outside of water), as long as the humidity is kept high! When transitioning the Java fern from the submerged to the emerged form (or vice versa) two things may happen; the plant will grow very slowly for a while as the leaves go through transition, the leaves may fall off, and new leaves will grow. After this transition period, the plant will begin to thrive again, but the entire process could take around three months!

Propagation

1. Separate healthy root systems with at least 2-3 leaf nodes from the mother plant. If a leaf is not doing well, it may produce plantlets that can also be propagated. You will begin to see this as black dots on the leaf body between the veins.
2. Position the separated sections so their roots are submerged and securely rooted in the substrate or attached decorations or driftwood.
3. It is important not to bury the rhizome* (the horizontal green stem) as it needs to breath through the water column and it needs to breath.
4. Provide moderate to high lighting, and maintain ideal water parameters (72°F – 86°F, pH 6.5 – 7.5, KH 4-8 dGH).
5. Monitor growth, trim away dead fronds as needed, and harvest new sections for further propagation or sharing.

* The rhizome is the horizontal green stem that new leaves grow out of. It will continue to grow and split. When the rhizome is buried underneath substrate the plant will begin to die off, and the leaves will activate their distressed mode. When the leaves are distressed and the leaf is mature enough, they will slowly die off while creating many baby plantlets for dozens of future plants! This is truly a spectacular plant! If you want to propagate a lot more plants in a hurry, this may be one way to go. Make sure you keep the plantlets healthy though!

Trimming

Trim old or damaged leaves at the base of the rhizome. If the plant becomes too large, the rhizome can be divided.

Notes, Tips, and Considerations

• Brown spots on the underside of the leaves are normal and indicate reproduction (sporangia).
• Provides shelter and hiding places for fish and shrimp and contributes to better water quality by absorbing carbon dioxide.
• Most fish do not find its taste appealing, making it resistant to many herbivorous species.
• It can also be grown in paludariums and terrariums with high humidity.
• The leaves typically reach a length of 10-30 cm and a width of 1-2 cm.

Naturally Found

• Regions
  • Asia
• Environment
  • Habitat: river
  • Water Type: freshwater
  • Water Depth: 0.1 – 1 m
  • Water Flow: slow
  • Light: low, medium
  • Temperature: 15 – 30 °C
  • Humidity: high
  • Substrate: bare