Java fern is one of the hardiest aquarium plants there is. It grows in low light, needs no added CO2, and attaches to wood and rock rather than rooting in the substrate. Along with Anubias it is the plant most often recommended to anyone setting up a first planted tank.
The name has changed
Java fern is currently classified as Leptochilus pteropus, having moved from Microsorum pteropus, and you will still see it sold under the older name almost everywhere. Both refer to the same plant. Aquatic plant naming genuinely does move around, so the trade name is often the more reliable thing to shop by.
Where to attach it
| Requirement | Java fern |
|---|---|
| Light | Low |
| CO2 | Not required |
| Difficulty | Easy |
| Growth rate | Slow |
| Placement | Epiphyte, mid to background |
Attach it to wood or rock and leave it alone. Like Anubias, it grows from a rhizome, and burying that rhizome in the substrate will rot it. Tie it on with thread or fishing line, or use gel glue, and the roots will grip on their own within a few weeks.
Its taller, mid-to-background habit makes it a natural fit for Nature Aquarium layouts, where much of the planting is epiphytes lashed to the hardscape, and for the low-tech Walstad method.
Brown or black patches on the leaves
Java fern reproduces by growing tiny plantlets on its leaves, and mature leaves develop dark bumps and patches as part of that process. It looks like disease and usually is not.
Leave those leaves in place until the plantlets are large enough to detach and attach elsewhere. If a leaf is genuinely dying it will go soft and translucent rather than firm and spotted, and that one can come off.
Java fern questions
Does Java fern need to be planted in substrate?
No, and it should not be. It is an epiphyte that attaches to wood and rock. Burying the rhizome causes it to rot, which is the most common reason a Java fern fails.
Is Java fern easy to care for?
Yes. It tolerates low light, needs no added CO2, and grows slowly enough that it forgives irregular maintenance. The main way to fail with it is to plant it wrongly.
Why is my Java fern growing so slowly?
Because that is what it does. Slow growth is characteristic of the plant, not a sign of a problem. It is also why the plant copes so well with conditions that would kill a fast-growing stem plant.