Java fern: super popular, looks great, and is pretty simple to care for.
In fact, java fern is one of the first plant species I ever tried to grow and propagate in my planted aquarium. I love it and have had great success with it.
Here’s an image of my mama java fern:
In this guide, I’m going to share my knowledge and experience with you about this popular aquarium plant.
You’ll learn everything you need to know to be successful, even if you’re a complete beginner.
Scientific Name: Microsorum Pteropus
Care Level: beginner
Growth Rate: slow
Tank Placement: mid to background
Lighting Requirement: low
Ideal Temperature: 70°-83°F (21.1°-28.3°C)
Water Hardness: 2-15 dKH (33.3-250.1 ppm)
Java fern (microsorum pteropus) is an aquatic plant native to parts of Southeast Asia. It was first described by Dutch-German botanist Karl Ludwig Blume in 1833.
It grows along the banks of freshwater rivers and streams in Thailand, Malaysia, India and China.
It is a true aquatic plant, meaning that it can grow and thrive while completely immersed in water. It can also be grown with the leaves sticking out of the water, but the rhizome and roots have to stay underwater at all times or the plant will dry out and die.
Java fern has three basic parts:
Leaves – these can be anywhere from ¼ inch to 12 inches long. In the natural form of the plant, the leaves are bright green, long, narrow and pointed
Rhizome – rhizomes look kind of like dark green roots, but they’re actually stems. They grow along the surface of whatever the Java fern is attached to.
The leaves grow out of the top of the rhizome and the roots grow out of the bottom. The rhizome is what absorbs most of the water and nutrients the plant needs.
Roots – dark brown, fuzzy roots grow off of the rhizome. But instead of absorbing nutrients, these roots mainly function to anchor the plant to something, like a log or rock, and keep it from being swept away in the current.
Java fern is an epiphyte, meaning its roots attach it to something, like a piece of driftwood or tree roots, instead of rooting itself in sand or soil.
Most plants draw water and nutrients from soil through their roots. However, Java fern works a little differently. It pulls these directly from the water column, instead of from underground.
Java fern reproduces by a process called apomixis. Instead of producing seeds that need to be fertilized, Java ferns clone themselves.
Underneath the leaves of mature plants, tiny baby plants, called plantlets, start to grow. Each plantlet is a perfect replica of the adult plant.
The plantlets develop roots and several small leaves. Eventually, they break off from the adult plant and get washed downstream until they can attach themselves somewhere and start a life of their own.
You may see Java ferns available that have different leaf shapes. Some leaves may be forked, narrow or even twisted.
Despite these differences, they’re all still considered to be the same species.
I know, it’s weird, you would think each one would be its own species. But clearly, the scientific community did not consult me on this decision.
They are all listed as Microsorum Pteropus, but with the variety name in quotation marks after the scientific name (e.g. Microsorum Pteropus, “Trident”).
Microsorum Pteropus, “Narrow Leaf”
Narrow leaf Java fern has much thinner leaves. As the plant matures, the leaves get a slight twist to them that looks really interesting.
Microsorum Pteropus, “Needle Leaf”
The leaves on needle leaf are even thinner than narrow leaf. The long thin leaves look almost crinkly and it’s hard at first glance to tell it’s even Java fern.
Microsorum Pteropus, “Trident”
Instead of the leaf coming to a single point, each one is forked with several fingers coming off the main leaf, kind of like the trident carried by Poseidon.
Microsorum Pteropus, “Windeløv”
The leaves on Windeløv look the same as regular Java fern until it gets to the ends, which separates into a bunch of frilly forks that curl around on themselves.
The first time I saw one, I thought a hungry fish had come by and shredded the plant! The look has grown on me, though, and I think it adds an interesting texture to the tank.
Various Uses for Java Fern and Compatibility
Java ferns make a great addition to the decor of your planted aquarium. Many aquarists attach Java fern to other decor to help create a more natural looking environment in their tanks.
Fish and shrimp love to hide and play in it. Mature plants make a great place for young or shy fish to find cover.
It’s slow growing, so it doesn’t eat up a ton of excess nutrients out of your water, but it does use up at least some of the nitrates (NO3-) in your tank, helping to keep the water column clean.
Is There a Best Tank Size?
I really wouldn’t put Java fern in a tank smaller than 10 gallons. It grows slowly, but it can eventually get pretty big.
I have mature ferns with leaves that are almost a foot long (30 cm) and the base of the plant is easily 8 inches (20.3 cm) around. That plant would completely overrun something like a 5 gallon.
What Fish Can I Keep With Java Fern?
One nice aspect of Java fern, apparently it’s not very tasty. This is a good thing. It means that a lot of herbivorous fish, like plecos, won’t completely destroy your ferns to eat them.
My clown pleco loves to tear apart other plants in my tank, but leaves the Java fern alone completely.
Now, some species will tear it apart anyway, I had a very large green severum that did destroy and eat the Java fern, along with all the other plants in my tank.
So it’s not an absolute guarantee, but it’s got a better shot than most other plants to survive fish that think live plants in the tank are a salad bar.
Water Parameters For Keeping Java Fern
This plant really is not picky about water parameters. It can tolerate water that ranges from very soft to moderately hard, as well as a wide pH range.
I’ve seen it used in blackwater tanks with almost no hardness and a pH of 6.5. I’ve also seen it do just as well in hard water with a pH of 8.0.
That’s the beauty of Java fern, it works for just about anyone, in any set up.
How to Plant
One of the things that I truly love about this aquarium plant is that it will grow just about any place in the tank. Since it doesn’t need to have strong light, or to be down in the substrate, you can jam it just about anywhere and it will grow.
The trick with Java fern is to weigh it down so it will stay where you want it in the tank. Otherwise, it will just float around in the tank until it finds a spot it likes, usually stuck to the filter intake.
Most people tie it to a rock or driftwood, or even resin decor with cotton thread or fishing line. Since Java fern is a epiphyte, its roots are really good at anchoring the plant to just about any surface they touch.
All you have to do is loosely tie the rhizome to your decor, like a piece of driftwood, cholla wood, rocks, shells, etc. After a few weeks, the roots will grab a hold on the decor and you can remove the string or fishing line.
Everywhere you look, you’ll see sources that tell you not to bury java fern down in the substrate because it will rot.
In my experience, this is true and false. So, you don’t want to bury the rhizomes down in the gravel, they will definitely rot over time.
But, if the fuzzy roots are long enough, you can cover them with just enough gravel to weigh the plant down. After a few weeks, the roots will stick to the gravel, even if you pick the plant up, the roots will hold on to a ball of gravel.
Then you can place the plant anywhere you want and the gravel will weigh it down. I use this trick a lot when I have baby Java fern and don’t have anything available to tie them to.
Also, if you have decor that has little openings in it, you can stuff pieces of Java fern down into it and it will grow there. I do this with resin decor all the time. Since I have an endless stream of plantlets, I put them in little swim through holes that are too small for my fish.
Buying Java Fern: How to Choose a Healthy Plant
Double check for leaves that are browned around the edges. The entire leaf should be bright to dark green.
Also, take a look at the rhizome. A healthy rhizome should be a dark green without any kind of browning.
Usually, Java fern is sold as a cutting from a larger plant, with only a few leaves attached to a piece of rhizome. The leaves may only be a few inches long. This is completely normal.
As the rhizome grows, it will put off new leaves that will get bigger as the plant matures.
How to Grow and Make it Thrive
Java fern is really undemanding and doesn’t require a fancy set up at all. Basic lighting and minimal fertilizing is more than enough to make it mature into a healthy plant. You don’t have to drop a bunch of money on a CO2 setup, either.
It’s kind of like that friend who says, “I’m cool with whatever you want to do.” It’s easy going and simple to please.
Java fern only requires low light. It will happily grow in light that would completely kill other kinds of plants.
It can also tolerate more intense light and it will grow more quickly under brighter lights. But it’s not a requirement.
You don’t have to use fertilizer with Java fern. But, it will grow much more quickly if you use a liquid fertilizer like Seachem Flourish or API Leaf Zone.
As for myself, I dose my tanks twice a week with the recommended amount of Flourish and have seen great results.
When I first got into live plants, I thought that my lights were too weak to even grow Java fern. It didn’t die or anything, but it didn’t really grow either.
But then I started adding the liquid fertilizer and the ferns and my other plants started going crazy. The Java fern will still grow more slowly than other kinds of plants, but you’ll start to notice a major difference from month to month.
You really don’t need CO2 to grow Java fern. Of course, it will grow quicker if you do use it. But frankly, I’ve grown so much Java fern over the years that I’ve had to give some away to friends because I ran out of room for it. And I don’t use CO2 in any of my tanks.
How to Maintain Java Fern
This hardy little plant doesn’t need much maintenance. Occasionally you’ll have an old leaf die off. Just pinch it off as close to the rhizome as you can get and toss the dead leaf in the trash.
Java Fern Melt
Sometimes, multiple leaves can start to turn yellow or brown, get mushy and die back.
This is really common when it is first added to a new tank. The old leaves have a harder time adjusting to the new water conditions, especially if it was grown from a tissue culture.
It’s best to trim any browning leaves down to the rhizome. Usually, the plant will get acclimated to your water and start putting out new leaves.
I’ve also found that I’ve had more trouble with Java fern melt when I wasn’t dosing any kind of fertilizer.
After I started dosing a comprehensive liquid fertilizer once a week, I stopped having any kind of melt. My plants rarely even lose old leaves.
Brown Spots Under Leaves
This one isn’t really even a problem, but people see it and get a little freaked out.
Rows of dark brown or black spots on the underside of leaves is nothing to worry about. It just means the adult plant is about to put off plantlets. Usually, each spot will become a baby plant.
Yay! New plants for free!
Plant propagation is the process of growing new plants by germinating seeds, rooting cuttings or splitting bulbs/rhizomes.
Propagating Java fern is really simple. Frankly, it usually does a great job of propagating itself. Once you see plantlets start to form on the edges of leaves, just wait until they have formed several leaves and trailing roots.
Then you can pull them off the parent plant tie them to driftwood or other decor. They’ll start to grow on their own with very little fuss.
Or you can snip off a section of rhizome with a few leaves attached. Each piece of rhizome you cut off will become a new plant. You can tie or weigh them down in the tank and they’ll start to grow.
Above is on of my Java fern plantlets growing on a leaf.
Is Java Fern Right for You?
When to comes to aquarium plants, I really can’t recommend this plant highly enough. It was the first species I ever tried to grow and I’ve had great success with it.
I bought one small piece years ago and I’ve been able to propagate it so many times that my tanks are full of it, even after giving a bunch away.
Java fern really is easy to take care of, you don’t need a fancy set up and it’s practically bombproof.
There are several different varieties available so you can have different shapes and textures in your tank to make things more interesting.
It really is a great addition to your tank and your fish will love it!
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