Java Fern: Underwater Plants For Water Gardens

Ed Wike
Written by
Last update:

Java Fern Overview

Java Fern are among the easiest plants to keep, and the most popular plants, in the aquatic world. They are popular among aquarium enthusiasts for their beauty as well as their ease of care. In fact some aquarium enthusiasts add Java Fern to their aquarium even before the water has finished cycling! Most other plants are more difficult to keep, and require considerably more care. Other plants are also much more expensive.

As the name java indicates, Java Fern are native to Indonesia. They are an aquatic, or sub-aquatic (meaning that they can thrive on land as well as in water) plant that can grow in water temperatures of 60 to 86 degrees Fahrenheit. They enjoy a lot of sunlight, but not too much. Too much sunlight can scorch the leaves. They can tolerate short periods of low light, but the leaves fade to green (some varieties become brown).

All About Java Fern

Java Fern (Microsorum pteropus) is one of the true aquatic plants that is considered to be a weed by many. This submersed plant has distinctive dark-green leaves that resemble fan-shaped plants. Java Fern, being categorized under a group of ferns, is a common aquatic plant that is usually preferred in fresh water aquariums.

If you are planning to place it in your water garden, then you might have to allow some time to let it establish itself.

Java Fern, unlike some other plants, enjoys a lot of light and some sunlight is necessary for its proper growth. Also, unlike other plants the highly modified root systems of Java Fern keep it in place. As Java Fern do not produce any visible roots, they are placed in planting baskets to act as a substrate. The roots of this hanging plant attach themselves to the rocks or the sides of the aquarium in which it is placed. Java Fern requires a moderate amount of fertilization but keep in mind that over-fertilization might result in it producing new growth at the cost of the older leaves.

Apart from a low light intensity, Java Fern also requires a low temperature. The water in which this plant is placed should have soft to moderately hard water conditions. Following a pH level between 6.5 and 7.5 is sufficient to keep it healthy. Java Fern also enjoys medium to high carbonate hardness and an alkalinity level between 8 and 12.

Java Fern Care

There are few aquatic plants that are as easy to grow as Java Fern. It reproduces quickly and you can watch it as it adds a shimmery, green blanket to the bottom of your aquarium. You can grow this plant in freshwater fish tanks, outdoor ponds, or right next to a waterfall in the moist forest. It’s perfect for anyone who has a green thumb.

Java Fern has been enjoying growing popularity for a long time. It’s a great easy-care plant for any household. To get started, you will need to check with your local garden center or aquarium retailer for recommended Java Fern plants. It’s sometimes found under other species names such as Microsorum pteropus and Microsorium pteropus.

Newly delivered plants will come with instructions that tell you how to plant it and the current recommended temperature and lighting for the new plant. Ask your retailer/gardener what kind of water plants are best for your freshwater aquarium. For Java Fern it’s different from tank to tank. Some fish are better off with live plants than others.

Light and Temperature

Java Fern is relatively easy to grow. A low-light level is suitable but plants will do well in more light. If you think they are looking unwell, try adding some aquarium plant bulbs or fluorescents. The temperature range is 72-82 degrees.

Java Fern can tolerate both lower and higher values.

They do not appreciate being placed in cool temperatures. This type of plant is excellent for newbies and casual plant aficionados alike. It is not sensitive to copper, which is a common complaint that plagues some species.

Java Fern can be planted in the substrate or floating in the water. When planted in the substrate, it can be attached to driftwood. It can also be attached to the side of an aquarium. Planting Java Fern using a plant clip will allow you to move it along the side of your aquarium. This is nice because you can change the look of your aquarium by changing where you place it.

Java Fern has a rhizome system (stem), usually coming out of rocks, rocks, and planting it. As Java Fern grows, it can extend beyond the rocks. It forms a network of plants. You can divide the plant at these points and replant new sections wherever you wish.

Water and Humidity

Java ferns love water and humidity. The higher the humidity and the more intense the light, the more likely the Java fern will grow well. You can keep these plants in small tanks where water is changed daily. Or, you can keep it in larger tanks where the water level is permanently low and the plants are exposed to less oxygen.

The key is to give enough light and to keep the tank atmosphere moist. You can choose fish-free tanks for the ferns or you can choose tanks with fish. Or you can choose something in between. You can use Java ferns to clean the air in aquariums with fish or in fishless tanks. In all cases, the key is to give the plant as much light as possible and to keep the atmosphere moist.


Java Fern is an aquatic plant that can be used in water gardens. In the wild, Java Fern grows in water, along the banks of rivers, and underwater. They can grow in full sun or shady areas. If your pond is not too deep, Java Ferns can be attached to a tree branch. In fact, the Java Fern will grow around the branch to take up the support.

Java Fern absorbs nutrients through its roots. In general, a Java Fern will produce runners every few months, which will grow new plants. The plants should grow from 3 to 4 inches in length within a couple of months of being transferred to a water garden. But don’t expect it to grow a lot more in the first year.

Be on the lookout for bacterial or fungal infections that can cause a sickly yellow color on the fronds. Fungal diseases tend to show up with brown or black spots on the fronds. The disease tends to start on the underside of the fronds, and spread to the upper side.

Beginning aquatic gardeners are often surprised by the amount of time they need to spend on the water garden. Even though Java Fern is very easy to maintain, you’ll still need to:

  • Monitor the pH and temperature
  • Remove dead leaves/fronds
  • Provide essential nutrients by adding fish emulsion or liquid fertilizer every two weeks


Some water plants need very little fertilizer, while others are ravenous consumers of nutrients. When in doubt about your specific plants' growth requirements, do a bit of research on how much fertilizer it might need.

Don’t use too much! Err on the side of less rather than more. It will cost more.

It's better to use too little than too much. Over-fertilization can cause nutrient burn on aquatic plants, and uneaten fertilizer can cloud the water.

The best fertilizer to buy is one that will match the plants' requirements. Water plants can absorb nutrients from several different sources, including the substrate, inorganic fertilizer, aquatic plants (if they have root systems), and fish waste.

Before fertilizing, test the water first to know what it contains. If it's too low in nutrients already, you don’t want to add fertilizer to it.

Propagating Java Fern Microsorum

Java moss may be more familiar to most of us as it can be found in most aquariums. To a fish keeper, it is a tasty snack. Microsorum pteropus is, on the other hand, food for aquatic insects and fish!

It is most used as an aquatic plant because of its interesting appearance, easy care, and versatility.

It can be grown in hard or soft water. It can survive in high or low temperatures. It can thrive with low light or full sunlight. And it can grow in a large aquarium or a small bowl.

If you are planning to add this plant to your aquarium, you will need to know how to propagate Java Fern.


Java fern is known as the “moss of the Caribbean” due to its frond's thin and leathery-feeling leaves, thin stems, and its slow growth rate. Java fern is easy to propagate, can adapt to a number of water conditions, and it’s a great choice for beginner aquarists.

Here’s a guide about how to take care of Java fern plants.

Repotting Java Fern Is Not Recommended as This Plant Is Very Slow Growing …

You should not repot or trim Java fern. It does not need to be trimmed frequently, like other plants. You risk rotting it when you trim Java fern.

Instead, use rock wool for your substrate, and that alone will keep it healthy and pretty.

To trim the plant for bottom growth, cut the leaves from above using a diagonal cut.

Java fern needs to be planted in a well-lit area of the tank. It cannot tolerate being in dark areas. The sunlight is needed for the plant to remove excess calcium carbonate in the water.

As long as the plant is planted in the substrate, it can be used to detect high levels of calcium carbonate in the water.


Java fern plants have air roots that allow it to grow on surfaces that it cannot be attached to. The main body of the Java fern plant can be attached to rocks or driftwood by the use of fishing line or a plant clip. Air roots can grow through the gaps between rocks and driftwood, to act as anchors to the surface that the plant is growing on. The Java fern has several air roots, so even if you prune some of them, the plant is still stable.

To prune Java fern plants, you should always prune them underwater. The plants need to be submerged for about 15 minutes before pruning. If you don’t do this, the plant can get air bubbles in the hidden parts of the plant and cause oxygen deprivation, which can kill the plant.

In the underwater environment, prune the Java fern plant by clipping the ends of some of the older roots. This encourages the growth of new, strong roots.

If you want to encourage the growth of new Java fern plants, you can clip the stems of some of the older plants – they can be up to six feet long.

Check the base of the plant for any signs of dead or decaying roots and take them off. Cut the roots as close to the plant base as you can and remove them from the tank.

Java Fern Problems

Many aquascapers keep Java Ferns (Microsorium sp.) as one of the sources of algae control in the aquarium.

However, one of the group members of my aquascaping hobby club reported that his Java Fern plants were not growing well and doing poorly.

This gave me a perfect reason to research further into this plant and to find more information on the plant’s care and possible problems that may prevent it from thriving.

Here are some of the problems associated with this plant and what you can do to avoid them:

  • Symptoms
  • Possible Causes
  • Probable Solution
  • Weak algae growth
  • Temperature too high
  • Add more shade
  • Leaves turning black
  • Light intensity too low
  • Add more shade
  • Leaves wilt and die
  • Water too hard
  • Adjust water chemistry
  • Edges of the leaves are not bright green
  • Light intensity too low
  • Add more light
  • Leaves turn brown
  • Water temperature too low
  • Increase temperature
  • Leaf tips turn brown
  • Water temperature too low
  • Increase temperature
  • Leaves turn yellow
  • Light intensity too low
  • Add more light

This was a very arduous research.Java Ferns are not an easy plant to research.

Many websites with care and feeding information were outdated and vague.


Growing Problems

If plants are not doing well and you’re not sure what’s wrong, it might be because of the kind of water you’re using.

Some sources of household water can contain copper, fluoride, chlorine or other elements that could adversely affect the plants in your water garden. If you use well water, chances are good that the minerals in the water are not good for your plants. If you have a well, we recommend that you consider the use of a reverse osmosis filtration system to remove the calcium, copper and other minerals that can cause your plants to stunt or rot at the stem. We’ve seen some really nice water gardens, but the plants are just short green spikes or they’re stunted and yellow. Picking out a water garden plant that is good for your conditions is the most important thing you can do. If you’re watering with hard water and your plants don’t seem to be thriving, you can try getting a Water Garden plant that is noted for its hardiness.

If you’re having moisture problems, try using a rock or gravel (depending on your style) that will help to slow down the flow of water flow and bring the water level up to the top of the pot.


Yes you read that correctly. Plants are not pests … as far as water gardens are concerned, we are talking about aquatic plants. We use the word pests when describing animals that are harmful to water gardens, and we classify plants that may grow out of control, or spread to other bodies of water as pests. To make it simple however, just remember that a plant is not a pest, even if it’s not the type of plant you wanted and it is growing in your water garden.

Every week, people email us about finding all kinds of plants coming up in their water gardens. They always want to know how to get rid of these unwanted plants, but rarely do we tell them to get rid of the plant. The truth is, that most of the time, the plants are doing no harm to the water garden and are just trying to survive. During wet seasons, lots of young plants, both desirable and undesirable, pop up in water gardens, especially if they are shallow. If you aren’t sure if a plant is growing in your water garden or just popping up there from the riverbank, leave the plant alone. It is almost never a good idea to eliminate a plant from a water garden without knowing what it is, and why it is there.


Java Fern is actually a tropical plant and is not at all susceptible to the ill effects of winter.

But the real problem with Java Fern is that it has an extremely fragile root ball.

This makes it rather difficult to transplant. Java Fern is often sold as a result of this, which is the wrong way of doing things.

The plant has to be buried with its roots in the substrate. The algae on the leaves is rather tough and can easily survive under normal conditions. The algae also adds a bit of swimming space between the leaves where the fish can hide easily.

If Java Fern loses its leaves, it may take some time for it to grow them back. But just like any other plant, it can be rooted from its leaves.

The stem and leaves should be about one inch long. You can also switch the leaves with the stems by burying them about two-inches deep.

Frequently Asked Questions

Why should I add Java Fern to my water garden? Java Fern is an interesting, easy to grow, hardy plant that has a naturally low nutrient demand and works well in either acidic or slightly basic water conditions. It’s attractive, easy to grow, and can help clean your water garden.

How do I keep the plant roots from becoming entangled in my air pump tubing and filter intake? Use two separate containers for the roots and the top of the plant. This keeps the roots planted firmly in the container, but the leaves and upper part of the plant sway freely in the water. Place the container in a protected area.

Another option is to keep the roots and top of the plant in separate containers and place the two containers under an upside-down pot (the “rump pot”).

Do Java Fern plants make good fish tank plants? Most of the fish that would eat Java Fern prefer live food. If you must introduce Java Fern to your fish tank, remove any dead leaves immediately. Java Fern roots are a tasty morsel for fish. Use a fine mesh screen over the top of the container to avoid those fish that are able to nibble through the air hose.

Q: Can java ferns grow out of water?

A: Yes. Plants belonging to the family of java fern are primarily grown in water. But they can grow as a terrestrial, flowering plant also. The exact classification is classified in the order of monilophytes, a plant group that grows without any roots, pinnately filamentous female gametophytes, a photosynthetic appendage of a gametophyte called flagellum, and that lacks vascular tissue.

Java fern are epiphytes, super cool plants that grow on another plants. They grow on trees, rocks, riversides, and other surfaces. The best place for these plants is basically any warm, damp place. These plants can survive in areas with up to 200-300 mm of rainfall. However,They can be extremely drought tolerant, and can even go for a month without water and still remain alive.

They like the temperatures between 65-85 ° F, and the best light is dappled shade or indirect sunlight. The different species prefer different light and temperatures. Some like it hot and sunny, and others like it cooler in a richly shaded environment. If planted correctly, these plants can flower up to five times a year. Some flowers are reddish-brown and others are pinkish and white.

Q: Does java fern need extra CO2?

Answer: One of the most attractive ways to bring underwater plants into your freshwater aquarium is by setting up a water garden. Water gardens are among the easiest freshwater setups to maintain. One of the most common water garden inhabitants is java moss (also called java fern). But there is also an aquatic plant that's referred to as java fern.

These three different types of plants share the same name:

  • Java fern (Microsorum pteropus)
  • Java moss (Vesicularia dubyana)
  • Java fern (Cardamine flexuosa)

What you should know is that all three types are very similar in appearance:

  • They have flat, leathery leaves
  • They tend to prefer moderate light
  • They possess an ability to attach to almost any surface with their leaves

Java moss is the most common water garden inhabitant. It spreads rapidly and it looks beautiful, but it requires CO2 supplementation and frequent adjustments in water parameters. It can also cause water quality issues, so it is not recommended for aquariums with fish.

Java fern, on the other hand, is much less aggressive. It only spreads by fragments that can be planted in other parts of your aquarium. It looks lush and has an ornamental appeal, but it has none of the algae-forming tendencies of java moss.