Java Fern

A slow-growing rhizomatous fern producing firm leaves from a horizontal rhizome. It tolerates low light and is commonly used in low-tech planted aquariums.

Starter values use the commonly reported optimum aquarium temperature range of 20–28°C and a broad pH tolerance of 5–8.

Injected CO₂ is not required for ordinary cultivation. Added CO₂ may improve growth, but the plant remains naturally slow-growing.

Position the plant on wood, stone, or another hard surface. The roots may grip the surface over time, but the horizontal rhizome must remain exposed.

Secure the rhizome gently to wood or stone using thread, plant-safe adhesive gel, or a loose tie until the roots gain a hold. Do not crush or completely coat the rhizome.

Remove old or damaged leaves near the rhizome with clean scissors. Avoid cutting healthy leaves unnecessarily because replacement growth is slow.

Divide a healthy rhizome into sections that each retain leaves and roots, or separate daughter plantlets that form on mature leaves once they have developed roots.

Black dots arranged on the undersides of mature leaves can be sporangia, the fern's reproductive structures, rather than disease.