A Complete Java Fern Care Guide: Planting, Propagation, Lighting, Care and Water Requirements


Java Ferns are great for any low-maintenance aquarium. Fish generally don’t like their taste and leave them alone, so they can be kept with a wide variety of fish species.

Java Ferns don’t even need substrate to grow. They are very easy to plant and propagate. They are very hardy and act as low-maintenance water filters. They need relatively less nutrients and low light.

As their leaves spread outwards, they give the appearance of a much larger plant. So you can have the appearance of more greenery without actually planting many plants.

Java Fern General Care

Java Ferns have roots just like most other plants. So, many of us assume that they need to be planted in the aquarium substrate. However, if the Java Fern’s roots are buried in the substrate, the plant is likely to die.

Unlike other plants, the roots of the Java Fern get their nutrients directly from the water. They need to be planted on objects like rocks or driftwood. The roots need to be exposed directly to the water.

Since Java Ferns suck out nutrients directly from the water, they are one of the best plants to naturally filter your aquarium water.

When new Java Ferns get established in an aquarium, their leaves spread apart, giving it its unique look. They also grow very slowly, so you don’t need to trim them often.

Many species that like to play with and uproot plants, like Goldfish, tend to leave Java Ferns alone.

Due to their height, Java Ferns are best planted towards the back of the aquarium. This way, the shorter plants can be planted in the front and won’t get obstructed. Also, the fish can go to the back and hide among its large leaves if they feel stressed or need to hide.

Java Ferns are great plants for beginners, as they can tolerate water fluctuations (upto a certain limit), rarely require trimming and can be kept with a wide range of tankmates.

Whenever there is some nutrient or CO2 deficiency, the leaves of plants start to discolour. However, the Java Fern’s leaves usually have black markings of blotches on them. There might also be small black bumps.

These black markings could mean trouble in other plants. However, they are normal in Java Ferns.

That said, when a Java Fern is unhealthy, its leaves will get yellow, beige or brown. This discolouration could be within the leaves or on their edges. So when you’re buying a new Java Fern, look out for these signs of bad health.

Java Fern Appearance

Java Ferns have bright green leaves that stand tall. If they are kept in bright light, the leaves will become darker. They are narrow and reach upwards. They can reach a height of over 13 in (33 cm) and a width of 6 in (15 cm). This makes them perfect for planting in aquariums with skittish fish that require plant cover to hide.

The leaves have a tough appearance and are leather-like to the touch. As we’ve seen above, they also have black spots or markings on them.

They also have rhizomes, which are brown thread-like structures from which roots sprout and grab the rock/driftwood surfaces.

There are some variations of the Java Fern available, all of which have the same care requirements. Some variants have leaves with smooth edges, while others have a ragged, spike like appearance.

Lighting Requirements for Java Ferns

Java Ferns need low to medium lighting. 1.5 to 3 watts of lighting per gallon of aquarium size is sufficient. The bulbs should be full spectrum, or 5000 to 7000 Kelvin colour temperature.

Lighting that is too intense will cause the leaves to ‘melt’. Brown spots will form on them, which will need to be trimmed.

Java Fern Water Parameter Requirements

Species NameJava Fern (Microsorum pteropus)
Hobbyist LevelBeginner
Water Temperature Range68 to 82° F (20 to 27.7° C)
Water Hardness Range (°d)3 to 8° d
pH Range6.0 to 7.5
Average Height12 in (30 cm)
Substrate RequiredNo
Lighting RequirementsLow to Medium

How to Plant Java Ferns in the Aquarium

Java Ferns should never be planted in substrate of any kind. As we’ve seen before, the roots should directly be exposed to the water, or they won’t be able to absorb the nutrients.

You can tie the roots to a decoration in the tank, or for a more natural look, to rocks or driftwood. Look for areas that are particularly rough or have cricks or openings. Such spaces will make it easier for the roots to attach themselves.

Dissolvable threads are available which will dissolve over time. Alternatively, zip ties can also be used, and can be removed once the roots take hold properly.

The roots generally take hold in a few weeks, after which the zip ties or any threads can be removed.

When Java Ferns are replanted to another spot, they initially grow slowly. This is okay, as the growth rate will increase in a few weeks. But it still won’t grow rapidly, as it is a slow grower anyway.

Propagating Java Ferns

It is quite simple to propagate Java Ferns. There are two ways to do this.

The first method can be done when your main Java Fern plant has grown large and wide. A part of the rhizome could be cut off from the main plant. Ensure that the part you are cutting off has roots and the stem and leaves still attached. So essentially you are dividing one plant into two.

Then, you can simply plant the second plant the same way as mentioned above.

The second method can be done even when your main plant is not very big in size. When the Java Fern becomes mature, black bumps appear on the leaves. After some time, tiny new leaves start emerging from these bumps.

These leaves can be cut off at the base, where they meet the mother leaf and planted as mentioned above. When they are tied, their roots will form and the plant will begin to grow.

Be sure to use a sharp pair of scissors to cut the baby plant, as blunt scissors can crush the baby plants, reducing the chances of them surviving after planting.

Common Problems with Java Ferns and How to Solve Them

 Sometimes, a newly planted Java Fern may not be growing bigger even after a fewer weeks. If this happens, it could be that the water in the aquarium does not contain sufficient nutrients. Java Ferns are particularly sensitive to iron deficiencies, and the leaves turn darker in colour till they turn completely black.

You can use liquid fertilisers that contain iron to solve this issue. They have instructions on how to use them and in what quantity. They should be the ones that can be directly be released into the water.

Brown spots appearing or the edges of the leaves turning brown are another sign of a dearth of nutrients. These will also be fixed by using fertilisers.

Another issue is Java Fern Melt. Large brown spots appear on the leaves, and the entire plant starts rotting and turning soft. This could be due to multiple factors like a lack of nutrients, too much light or algae growing on the leaves.

Related Questions

How to remove algae from Java Fern?

The algae may or may not be visible. If it’s not visible run your fingers along the length of the leaves. If they feel slimy, it could be algae. If you have algae eating fish or snails or shrimp, you can skip feeding them for 2 or 3 days. They will eat up the algae.

It you don’t have any species that eat algae, you can see different things you can do to get rid of algae over here.

Can Java Ferns be Grown Partially Emersed From the Water?

Yes, Java Ferns can also be grown with the roots underwater but the leaves above the waterline. In fact, they can even be grown completely above water! As long as their enclosure is humidified and the roots stay wet with nutrient-rich water, they can still grow.

Syed Baseeruddin Hyder

I’ve been keeping fish and invertebrates in aquariums for over 5 years. Over the years, I’ve kept more than 15 different species of fish and invertebrates. Through ParadiseInATank.com, I hope to guide new and experienced fish keepers alike with as detailed information as I can get.

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