Java Fern

Java Fern is one of the few aquarium plants that grows better when tied to a rock than planted in the substrate. The rhizome — the thick horizontal stem the leaves grow from — rots if buried. Its true roots help anchor it to hard surfaces. The roots may enter the substrate, but the creeping rhizome should remain exposed.

The leaves are thick, dark green, and slightly leathery, with a pointed tip and a visible network of veins. The standard form has solid leaves, but cultivated varieties exist with forked (Windelov) or narrow (Needle Leaf) leaf shapes. A mature plant under good conditions reaches 20 to 25 cm.

Low light is sufficient, CO₂ injection is not needed, and the temperature range of 20 to 28 °C with pH 5 to 8 covers most community tanks. Growth is slow, so inspect the older leaves and judge establishment by healthy new growth rather than a fixed leaf-production schedule. Old leaves that turn brown should be trimmed at the rhizome.

New plantlets form on the edges of older leaves, starting as small green nodules that develop roots and tiny leaves. These can be removed once they are about 2 to 3 cm tall and tied to new hardscape. Java Fern is also resistant to plant-eating fish, which makes it one of the most reliable choices for beginner and low-tech aquariums.