Java fern is a timeless classic. It’s one of the most popular aquarium plants that has been around since the dawn of aquarium times.

It’s popular for the obvious reason - that it’s an incredibly gorgeous plant, it’s ridiculously hardy with regards to water quality and it’s readily available at pretty much any local or online fish store.

Java fern is also extremely resilient when it comes to resisting herbivores. It’s one of very few plants that work well in African cichlid or silver dollar tanks. Follow along as I cover everything you need to know about Java fern in order to grow the healthiest plants possible.

The accompanying video to the blog -> Ultimate guide to growing Java Fern

Appearance and Varieties

Some characteristic features of Java fern are really thick, leathery leaves, which is part of the reason that fish won’t eat it. Apparently it also tastes bad… I don’t know who figured that one out lol. One of my favorite things about Java fern is the strong venation. They show up as two lines of cells that run up and down the leaves. In a healthy fern, the cells will look like they’ve been stamped in wax, almost popping out of the leaf.

Even though there are many different types, Java fern is actually one species - Microsorum pteropus.

Really large ones
Really small ones
Single stranded leaves
Ruffled leaves
Trident shaped leaves
Just to name some of the varieties of java fern - windelov, philippine, miniature, narrow leaf, trident, sunset and needle leaf.

Java fern leaves grow off of a rooty stem, known as a rhizome. For the most part, when you first buy one, it’ll look like it’s kind of growing horizontally off the rhizome. Eventually rhizomes will criss cross growing in every direction, and fern bushes end up looking round. Smaller varieties have leaves about the size of a finger, but most are larger and can easily outgrow any tank without pruning.

Rhizome and roots on a narrow leaf Java fern.

Coming out of the rhizomes, you’ll notice that there are lots of fibrous roots. You can trim some of these if you don’t like the way they look, but you’ll want to leave a lot of them in tact for healthy nutrient uptake.

Origin

Java fern can obviously be found in Java, but it also grows in the wild across Malaysia, Thailand and in some of the tropical regions in China. It grows in tropical jungles alongside creeks. It often times grows alongside creeks where it can be fully submerged and fully emerged from water depending on the time of year.

Care & Water Parameters

This is the most forgiving plant that you can put in your aquarium. It tolerates an incredibly wide range of parameters and doesn’t need much light or nutrition. That being said, you can stick it in a high tech tank and get insanely dense growth from this plant.

Java fern is known for its slow growth, but as plants become established in aquariums they grow faster and faster with large plants growing exponentially quick.

In terms of specific parameters, Java fern does best in

pH of 5 - 8
GH 0 - 30
KH 0 - 15
Flow - low to high - if it’s really low you’ll want to brush it off every now and then to prevent debris from settling and growing into algae
CO2 - Not required
Lighting - extremely low to pretty high
Temp 65 - 83 ℉ or 18 - 28 ℃

This is probably one of the widest ranges of parameters that you’ll see for any species. That’s one of the reasons that Java fern is so popular. It’s great for typical planted tanks, high pH African cichlid tanks and even on occasion has been found in brackish tanks, though that’s where you’ll start to see less than vibrant Java fern growth.

When it comes to place a new Java fern in your tank, you’ll want to make sure that the rhizomes are not in the substrate, whether that's soil, sand or gravel. I mentioned that briefly already, but rhizomes need to have access to the water column for nutrient uptake and gas exchange. It’s perfectly fine to rest them on the surface of the aquarium, maybe use a little weight like a small rock over part of the rhizome. Eventually roots will set into the soil holding the plant in place.

You can also attach it to sticks or rocks using super glue or sewing thread. Just go easy on the glue, too much and you can suffocate the rhizome.

Trimming

Trimming Java ferns isn’t absolutely essential for maintaining a healthy plant, like it is with stem plants. That being said, there are some helpful tips to maintaining a Java fern.

First thing, SUPER IMPORTANT, you don’t want to hack back at a java fern the same way you would a stem or carpeting plant. You can’t just start trimming everything back to the desired length. You need to trim individual leaves. Think about each leaf as being all or nothing. Cutting a leaf in half will cause it to start forming holes and discolorations.

If your goal is to keep the plant small, the best way is to be constantly trimming leaves off the rhizome as soon as they hit a certain size. In a healthy plant, you’ll get enough leaf turnover that this will be sustainable.

It’s fairly common for the oldest leaves on a plant to essentially grow old and die. At this point they’ll appear full of holes, turn brown and shriveled. They will however, not fall off the plant. It’s best to take some scissors and cut at the base of the leaf - cutting the dead weight.

If your plant is healthy, bright green and growing lots of new leaves then this is nothing to worry about. If most of the plant is looking like that, then you might have an issue.

Java fern petite with a cherry shrimp

Common issues in Java fern

Even though this plant is super hardy, there are a couple issues that can pop up. Translucent leaves, holes in leaves and large scale browning of the plant… These aren’t good signs and can be caused by two main issues. Translucency is more closely related to intense lighting. That’s easily resolved by lowering your light or moving the Java fern to a shaded area.

I do think it’s worth mentioning that even though it’s generally accepted in the aquarium industry that high lighting can be bad for Java ferns, I’ve kept them under intense lights on many occasions. I think part of the equation is the use of routine fertilizers and CO2 in tandem with strong lighting. If Java ferns don’t have the fuel to grow under strong lights, they can fry.

Browning and steady appearance of holes is caused by low nutrition. You can go online and find charts that specify how particular nutrient deficiencies manifest in plants and then go buy those nutrients. Rather than playing scientific investigator, I’d recommend that you just get a nice all-in-one fertilizer.

There are so many terrific brands to pick from - if you have a heavy fish load, then you could just get some micro nutrients. If you have a light fish load, go with a heavier fertilizer like Niloc G, APT 3 or Easy Green.

You’d have to have really low nutrient load in your tank to experience major issues with growing Java fern. Regardless, adding some fertilizer to your water column will really help to boost Java fern growth. It’ll also benefit other plants in the tank, so it’s definitely worth considering.

One last issue with Java fern is algae growth. As with all slow growing plants with large leaves, algae growth can happen. There are generally two solutions to algae growth on Java fern. First, increase the flow. Stagnant water allows for sedimentation along leaves, which inevitably results in algae. Second, work on giving the plant more nutrients or better light.

Unhealthy plants aren’t able to fend off algae the way healthy plants are. I’ve seen tanks with tons of algae on hardscape, but none on Java ferns, because they’re healthy.

Propagation

Java fern is really easy to propagate. There’s a few different ways that this can happen. I’ve already touched on the first way - that’s just to rip a chunk of the rhizome off. It can be as big or small as you want, as long as there are a few leaves coming out of it. Eventually that clipping will grow to the size of the mother plant.

If you see roots forming at the tip of leaves, chances are that’s a baby plant budding off the mother plant. The roots that you’re seeing are coming off the baby plant's rhizome. They are really easy to pull off and place elsewhere to grow.

Do you see any baby ferns budding off of the larger plants? How about the zoom in on the picture below?

The last way to propagate Java fern is completely up to the plant - by release of spores that develop into new plants. The underside of leaves might have rows of little brown bumps, sporangia, just like the tracker pads from old laptops. Sporangia release spores, which grow into plants over long periods of time. I’ve had this happen on a couple of occasions, but I wouldn’t count on it for reliable Java fern cultivation.

I hope you learned something

Java fern is such an incredible plant. I absolutely love it, use it in so many of the tanks that I set up for myself and for clients. Hopefully you enjoyed the blog. If you live in Norther Colorado and would like to purchase some Java fern or need help with your aquarium, get in touch!

If you have any questions or want to share your Java fern experiences, drop a comment.

The ultimate Java fern care guide