Aquarium plants Articles Plant caresheets

Growing Java Fern (Microsorum pteropus)

Last Updated April 4, 2020
Windeløv java fern

Java fern is one of my personal favorite freshwater aquarium plants for many reasons! This particular fern is very easy to care for as it doesn’t need additional carbon dioxide, a strong light, specific substrate, or any extra fertilizers. It’s also one of the only plants that work great with fish that are prone to picking at leaves, like fancy goldfish

Keep reading for more information about Java fern care and how you can grow this wonderful aquatic plant in your tank!

Minimum recommended tank size10 gal (38L)
Care levelEasy
PlacementMid-/background
Temperature60-83 °F/15-28 °C
pH6-7.5

Name

Leptochilus pteropus (also referred to as Microsorum pteropus) is commonly known as Java fern. Different types of Java fern may be labeled based on leaf appearance, “narrow leaf,” “needle leaf,” “Windelov,” or “trident,” but are still considered L. pteropus.

Identification

As true aquatic plants, Java ferns can grow when completely submerged in water or when partially out of water; as long as the rhizome sections are covered, these plants will grow even if water parameters are not ideal! They are easily identifiable by their leathery green or brown leaves that are connected to their root system. The leaves even come in several different shapes and sizes for your choosing, and are named accordingly:

  • Narrow leaf Java fern: long and skinny leaves with the plant growing to around 10-12 inches (25-30 cm).
  • Needle leaf Java fern: even thinner leaves than that of Narrow leaf variations, with the adult plant size reaching 6 inches (15cm).
  • Windelov Java fern: the bottom of the leaf is bladed, while the top of the leaf has a ‘shredded’ or ‘lacey’ appearance. The whole plant grows to about 4-7 inches (10-17 cm).
  • Trident Java fern: narrow leaves fork off from each other, creating a ‘trident’ appearance. The average growth is 6-8 inches (15-20 cm).
Java Fern Care Guide

If you are not sure about the specific variation of your Java fern, the good news is that all types of this species require basically the same amount of care, which is minimal! It can be expected that your plant will grow to at least an average size of 8 inches (20 cm) regardless, with color depending on the placement in your tank and light conditions provided; the happier your Java fern is with your light, the greener it will be and the more that it will grow new plantlets.

If your plant turns completely brown or transparent, it may be dying and you should prune the leaves. However, what makes these easy plants such a popular choice for the planted aquarium is the fact that they do not need much lighting at all. Java ferns have been known to grow under very minimal light conditions and imperfect water qualities; this plant could even grow under the regular fluorescents that came with your tank!

Note: If black or brown spots begin to appear on your Java fern, it may not actually be dying. This is could be a sign that it may be getting ready to propagate. We will touch on this later in the article.

Natural Habitat

Java fern is found across Malaysia, Thailand, northeast India, and some regions of China; the plant earns its name from the Indonesian island of Java. It can usually be found growing with its roots attached to rocks, to other tree trunks or roots, or sinking itself into the substrate. As these ferns grow like a weed, they are found in a variety of areas with no indication of preferred water quality, flow, or lighting. However, these plants seem to favor tropical rainforest streams and waterfalls where the leaves make a bed of green on the bottom of the water. Naturally, this becomes a great habitat for fish and invertebrates.

Should Java fern be planted?

The way Java fern should be planted is a bit different from what many aquariums keepers are used to when handling plants. The species can grow quite tall, up to around 14 inches (35cm), which makes it a great mid- or background plant that will fill out the back areas of your aquarium.

Unlike most aquarium plants, Java ferns don’t appreciate being planted in the substrate. They will actually grow very slowly or die off completely when their roots have been buried. Java fern has evolved to anchor itself to porous rock or driftwood using its amazingly strong roots instead. To make up for not growing in soil, it has adapted to absorb and store most nutrients through a specialized part of their roots called the rhizome.

This means you can tie your Java fern to a piece of porous rock or driftwood, like lava rock, using some thread, fishing line, or super glue, and it will eventually attach itself; if using super glue, make sure the only ingredient is cyanoacrylate as this is completely safe for the plants and fish in your aquarium. For more information on how to do this, have a look at this guide.

The roots should quickly fasten onto the surface of the wood or rock until the plant is fully attached after a few weeks. In fact, you’ll have to make quite the effort if you ever want to remove it from its anchor point!

Photo by Pinpin

Java fern care

Once you’ve planted your Java fern, there really isn’t much else you need to do other than keep an eye on it and occasionally trim it if it starts to take over your tank.

  • In low light, low tech setups, it may take a while before the plant really gets growing. Once the Java fern has fully attached to its surface, it should start slowly expanding into a large fan shape and eventually start propagating by creating and releasing tiny new plantlets. You may even have to remove some leaves once it gets too large.
  • In a more advanced aquarium setup where extra fertilizers, carbon dioxide supplements, and specialized lights are used, the plants start to grow a lot sooner after first being added to the new aquarium. These things are not necessary at all if waiting a little longer is no problem.
  • One interesting point about Java fern is that it can actually be kept in brackish water. If you’re setting up a low- to mid-end brackish aquarium (salinity up to around 1.009) and are having trouble finding plants to decorate it, look no further! Unlike most aquarium plants, Java fern can handle quite a bit of salt in their water and should grow normally once acclimated.

Java fern tankmates

When it comes to combining Java fern with fish or invertebrates, almost anything goes! Its hard leaves make it unappetizing to fish that normally love to nibble on any plant they find, such as fancy goldfish or herbivorous cichlid species. These leafy forests are highly appreciated by fish that prefer plenty of hiding places, such as bettas and (dwarf shrimp) fry, as they offer a safe place to forage and hide. The only aquarium inhabitants that could become a problem for your Java fern are destructive crayfish varieties.

It should be noted that Java ferns are more prone to being eaten or destroyed if they are still little. Young plant leaves won’t be as thick as adult plant leaves and are more easily nibbled at. If newly introduced to your tank, the roots may also not be strong enough and may not be able to fully attached themselves to the driftwood or rock yet. This makes the plant very easy to knock loose into the water and float free around your tank. If putting your fern with more active, aggressive fish, make sure the leaves are developed and the roots have attached to the wood or rock.

How to grow Java fern in your aquarium!
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Problems with Java fern

Although Java fern is a very easy plant and suitable for many planted aquarium beginners, you may still encounter some problems keeping it in your tank. For example, the first assumption is often that more light will help your plant grow better. While this is often the case with other aquatic plant species, it does not hold true for Java fern. If you’re having to remove a lot of transparent or brown leaves from your Java fern, the light you’re using may be a little too strong. Time to turn down the light for a little while!

For cases such as this, the best bet is to slowly acclimate your Java fern to the lighting conditions in your tank over an extended amount of time. If your light spectrums are adjustable, lower the intensities; slowly bring them back up over the course of the next several weeks until back at the original values.

If your Java fern is just not growing like it’s supposed to even after patiently waiting for a few weeks or months, there may not be enough nutrients in the aquarium water for it to really thrive. Regular doses of liquid fertilizer should help get it going.

Java fern propagation

This plant usually propagates asexually on its own time, but there are a few easy ways to speed up the process. The most common way of propagating your plant is by waiting for plantlets to grow on the edges of the parent plant. Wait until the new plantlet has grown several leaves and a defined root system, then remove the plantlet and attach it to a surface with the same technique as with the adult plant. You can new growth is happening when the leaves of the adult plant start developing black or brown spots (as long as there would be no reason for your plant to die, such as water conditions!). These are the areas from which the plantlets will grow. So be on the lookout!

The second method is by cutting the rhizome in half and replanting the root just as before. Over the course of several weeks, your plant will start to grow into its own new individual aquarium plant!

Buying Java fern

If you’re interested in growing Java fern in your own planted aquarium, you should be able to find it in any pet shop without any problem; it’s a very popular choice and a great addition to any tank. The only difficulty will be picking out which variety of Java fern plants you want!

Most aquarium stores carry Java fern and you can also find all varieties and sizes online, sometimes even already attached to driftwood. Just find a seller with good reviews, like SubstrateSource. If you don’t want to buy your Java fern from a store, many aquarists also sell their clippings for a low price or even just to cover the shipping costs.

Conclusion

It doesn’t matter whether you’re a beginner, advanced aquarist, or if your aquarium is low-tech or a high tech aquascape, everyone is able to grow Java fern. It’s also a great choice if you’re aquascaping plants on a budget. Although it grows relatively slowly, it should eventually turn into a large, impressive plant that will also continue to create plenty of new little plants to fill your tank!

If you have any more questions about caring for or growing Java fern in your aquarium, or if you want to share your experiences, feel free to leave a comment below. Happy fishkeeping! 

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10 Comments

  • Reply Lexus U April 20, 2018 at 7:08 pm

    Hello! Newbie Java fern mom here. So It looks healthy as far as I can tell but seems to have growing extra plants from it’s leaves? They each have a green center nub..which then has smaller brown fury like testicles growing from it attached to mostly the tip portions of the plant. Any ideas about this? Thanks in advance!

    • Reply Mari April 22, 2018 at 10:02 pm

      Hahaha! Yes, this is normal. Java ferns grow little plantlets which are eventually released and float around until they find a surface to attach to. You can just leave them until you find them floating and then replant or place them wherever you want 🙂

  • Reply devoney November 15, 2017 at 6:21 am

    Hi there! This is a bit of a long problem, sorry.
    I have two java ferns in my tank, which is a 5-gallon Solo Desktop Aquarium, planted, with a betta, a waterweed, and 5 marimo moss balls. There is a 50-watt heater and 40G sponge filter, set to a low current with the control valve. Currently I’m not sure if my tank is cycled because the sponge filter is still very new (replaced the Solo filter with it a month ago) and I have been testing the water parameters since then, which all say I have 0 anything in my tank (ammonia/nitrates/nitrites). Not sure if this means cycled or just I have enough plants to filter it all?
    Anyways, I have had problems on and off with the tank, but currently my java ferns are not growing very quickly (or at all from what I can see), and the adult leaves are getting brown spots and holes, and I’ve lost a few leaves. Last week I found one baby fern that had gone completely white with a few yellow patches. They have barely grown since getting them 4-5 months ago, only produced a lot of babies, but now they really seem to be suffering.
    Not sure what’s wrong with my tank?? I’ve been dosing Flourish Potassium for about two weeks and no changes. Please help!

    • Reply Mari November 22, 2017 at 11:41 am

      Hello!

      I can’t tell you much about whether your tank is cycled either. 0 nitrates is suspicious but then again liquid nitrate tests aren’t always accurate and can falsely display 0. So I’d double check that (you can Google how to make sure your test is working) and if it still displays 0 I’d just keep a super close eye on it. One thing – next time you can make sure the tank stays cycled by running both filters for a month or so before removing the one you want to take out (unless the previous one was broken, that’s just bad luck).

      As for the Java ferns, it can be super difficult to figure out why they’re not doing well. Dumb question maybe, but are they attached to rock or driftwood as they should be? They can die off when planted in soil. If that’s not it, I did find a thread that lists a couple of things you can consider here. Hopefully the solution is in there.

      Good luck! I hope the ferns recover or you can at least figure out the problem. 🙂

  • Reply Jason February 22, 2017 at 1:45 am

    Great article. What if I am getting brown spots on the fern?

    • Reply Mari February 23, 2017 at 10:15 am

      I find they do get brown spots even when nothing is wrong. If it’s getting really bad your lights may be too strong or you may be dealing with some type of nutrient imbalance/deficiency.

  • Reply Laura June 9, 2016 at 2:28 pm

    Hi there. This was a good article. I’m just starting my first aquarium. I have a Java fern and no fish yet. I just tested my water and my pH is 8.2. I tested my tap water and it’s the same. Is this going to be a problem and if so what can I do about the pH? I’ve read that it isn’t good to use those lowering pH drops. Thanks for any help you can give.

    • Reply Mari June 12, 2016 at 5:47 pm

      I don’t think it’ll be too much of a problem, Java fern is very hardy 🙂

  • Reply Michael September 27, 2015 at 11:50 pm

    Thank you for the information on Java fern. I always enjoy your posts and find them very informative.

    • Reply Mari September 28, 2015 at 11:31 am

      I’m very glad to hear that! Always happy to help. 🙂

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