Skip to Content

Java Fern Care — Budding Gardener’s Guide

Java Fern Care — Budding Gardener’s Guide

If you are searching for an aquarium plant, we have a suggestion. The Java Fern grows slowly, looks beautiful, and is easy to care for. 

The scientific name is Microsorum Pteropus, and it comes from the Polypodiaceae family. This would be a perfect plant for your water garden. 

In the native area of South East Asia (China, Taiwan, and Malaysia), this jungle plant is found growing in different locations such as on top of rocks, the waterline of the streams, and next to trees. 

This plant was first described in 1833 by a botanist named Karl Ludwig Blume. You’ll find it in almost every fish store, and it’s not expensive. 

I would recommend buying the one that comes with driftwood so you can directly transfer it to your aquarium.

Another reason for its popularity in aquariums is the unappealing leaf structure which prevents the fishes from eating the plant. 

Even the taste is unpleasant and bitter, so herbivore fishes also avoid it. 

The overall shape of the leaves depends on the variety you are growing, but they are mostly spiky or bushy, varying in hues of green. It loves growing in a freshwater aquarium, so it’s always in high demand. 


Java Fern Care

The water temperature for this aquarium plant should be 68 to 82 degrees Fahrenheit (20 to 27.7 degrees Celsius). Whereas the pH of 6-7.5 is ideal. It grows well under low light in the aquarium. 



We know that this water plant grows from the rhizome, which should not be buried. It’s an epiphytic plant so attach it to aquarium rocks or driftwood. 

Tie the roots or rhizome string with fishing wire. Once the roots have attached themselves to the support, you can remove the wire. This will usually take 3-4 weeks. 

It cleanses the water by absorbing some of the nitrates in the tank. This plant can be placed alone or grouped with other varieties of Java Ferns

It grows well in both cases. It is safe to be kept around different varieties of fish.



Just like potted and garden plants, this one also needs a growing environment similar to its natural habitat. 

Try to replicate the natural environment of this plant in the tank. This one grows close to streams and rivers. 

The filters in your aquarium will supply oxygen for this fern. The pH should be 6 to 7.5. The KH levels should be around 3-8. 



This water plant needs low to moderate light for growth. 

It’s not very finicky about the lights, so you can use incandescent bulbs or a dim fluorescent bulb in the tank. 

If you accidentally expose the plant to strong light, you should dim or turn off the lights for a few days and let the plant recover on its own. 



Since this is an aquarium plant, you should be concerned with the water temperature rather than the atmosphere temperature. 

The water temperature for growing a Java Fern should be around 68 to 82 degrees Fahrenheit (20 to 27.7 degrees Celsius). 

This plant can be planted in any tropical or cold water tank. 



Just like other water garden plants, this one also takes nutrients from the water. But, it doesn’t mean you can’t add extra to help the plant thrive. 

Fertilizer is optional for this beautiful fern, but it definitely helps in growth. 

Solid fertilizers are not recommended for this plant as it does not have true plant roots. I would suggest you supply a liquid fertilizer that can be added whenever water is changed. 



Pruning for this aquarium plant entirely depends on what type of growth and look you need in the tank or aquarium. 

To prevent the plant from taking up space in the tank, you should prune the tiny plantlets on the leaves. This will keep the plant from tangling or growing too big. 

However, if you are aiming for a bushy appearance, let the plant grow as it likes. 

You should also trim any burned or damaged foliage while pruning. Trim the leaves close to the rhizome. 



Propagation is a useful procedure in the soil and water garden. I have tried the following propagation method for this aquarium plant. 

  • Make sure only sharp and sterilized tools are used in propagation. Else, you might end up damaging your Java Fern. 
  • Divide the rhizome is multiple sections and plant them separately. Each section will grow into an individual plant. 
  • You can also cut the leaves sprouting from tiny black bumps. All these leaves can be propagated separately. These plantlets will produce a perfect replica of the original plant. The adventurous plantlets are mostly observed on old leaves. 



A newly bought plant is usually 3-5 inches (7.6 – 12.7 cm) in size. This green plant is made of foliage and rhizome. 

If you’re buying in bulk, make sure the rhizome is not missing. It’s a slow-growing variety, hence, it’ll take several weeks for Java ferns to grow. 

The rhizome is dark-colored thread-like roots that attach themselves to different surfaces. The rhizome serves as an anchor and stems for this plant. 

The rhizome is dark green, and the roots are dark brown. 

The roots will sprout from the bottom, and leaves will sprout from the top of the rhizome. The leaf size varies from plant to plant, but the traditional Java Fern has long, pointed, bright green leaves. 

Java fern’s size can be between ¼ to 12 inches. Once mature, this plant will grow 8 inches wide and 13.5 inches tall.

The foliage comes in different shapes, but it’s hardy with a leathery texture. You will also notice dark brown or black bumps and veins on the leaves. 

Most varieties have large-sized leaves, so this plant will serve as a background in the aquarium. 

If you do not notice any signs of growth during the initial days, do not panic because your plant is trying to adjust to the aquarium environment. 

Once the rhizome has successfully attached itself to anything in the tank, the fern will start growing. 


Varieties of Java Fern


Needle Leaf

This one offers thin, small leaves. The maximum size for this variety is 6 inches only, so it would fit perfectly in a small aquarium. It’s rarely available in the market. 



The special feature of this variety is the lobbed leaves. Each leaf side can have a minimum of 2 and a maximum of 5 lobes. 

This fern’s smaller in size compared to the narrow leaf variety, but it’s a fast grower. 


Narrow Leaf

As the name suggests, this one has narrow leaves. Individual leaves can be anywhere from 4-8 inches, but they grow at an angle. 

A mature Narrow Leaf Java Fern will grow about 12 inches big. As the fern grows, the leaves become twisted. 



This unique variety reaches a maximum size of 8 inches and has fine branched leaf tips. 


View this post on Instagram


A post shared by THE FISHGEEK (@the_fishgeek)


Common Problems for Java Fern


Dark Spots on Foliage

If you notice dark-colored bumps on the leaves, it indicates new plantlet growth. The plantlets will grow from these spots. This is completely normal. 

But these spots can also mean burns or a nitrogen deficiency. If this happens, dim the light within the tank or feed with nitrogen-based liquid fertilizer. 

Whenever there is a lighting issue, I turn off the lights for about three days and cover the aquarium to help my Java Fern recover from light damage. 

The blue-green algae found in the tank can also cause spotting. So if the issue is left unresolved, you will lose the plant. The plant will turn mushy, rot and eventually melt. 

The algae that damage this fern is made up of a bacteria called cyanobacteria. Once the plant is infected with these bacteria, it will have a thin layer of slime on the foliage. 

Poor nutrient levels in the water cause the growth of these bacteria. 

This thin slimy film should be removed from all plants and surfaces in the aquarium. 


Tips for Growing Java Fern

  • Try to attach it to a rough-surfaced area; otherwise, it will take longer to grow and attach. 
  • Burying the rhizome will result in rotting.
  • You should use black-colored thread or ties as they will not be prominent and blend with the roots. 
  • Avoid placing in the front of the aquarium because tiny aquarium plants will be hidden behind the foliage. 
  • You can achieve a dense jungle effect by letting the plantlets grow instead of pruning them. 
  • Pruning should be performed once a year to keep maintaining the neat look of the plant. 
  • Take special care while cleaning the tank because this plant needs to stay moist at all times. You can either keep it underwater in a container or spray it to maintain the moisture on the foliage. 
  • If you are keeping this plant with large fish, make sure you tie it well; else, it will be knocked over by the fish.
  • Java fern grows well in an aquarium with low light.  
  • Choose a liquid fertilizer that has iron. It helps the plant stay green. 


Frequently Asked Questions about Java Fern Care


What is the minimum size of the tank for this plant?

Choosing an appropriate tank size is important to help your water garden thrive. I would recommend planting the Java Fern in a 10-gallon tank or aquarium. 


What is the best spot for Java Fern in the aquarium?

You can place it anywhere in the background or middle of your fish aquarium. 


Can the Java Fern only grow fully submerged in water?

This aquarium fern can be grown partially or fully submerged depending on your likings.


Can you grow Java Fern outside water?

It is possible to grow this fern variety out of the water, but the water requirements will be very high. Even when it grows on the ground in the jungle, it’s sprayed with water from nearby waterfall and streams. 


What happens if the Java Fern is exposed to strong light?

In the natural environment, this plant grows in shaded spots with little sun exposure, so it does not appreciate strong light. If the light within the tank or aquarium is too strong, the foliage will turn brown or transparent. 


Can you grow the Java Fern in a bare bottom tank?

This aquarium plant does not require any substrate for healthy growth, so it’s a perfect candidate for bare bottom tanks. Burying this fern under a substrate will result in slow growth or death of the plant. 


What happens if you let the Java Fern float on the tank surface instead of submerging it?

Although it will grow well, the root of the rhizome will keep growing until they find something to attach themselves to. The roots hanging in the aquarium will create a messy display, so it’s better to grow it inside water.


It’s been several months, but my Java Fern is not showing any signs of growth. Why is that?

It’s normal for this plant to not grow any leaves in the first few weeks, but if it’s taking months, the water in your aquarium might not have enough nutrients. You can revitalize the plant with a dose of liquid fertilizer but strictly follow the instructions on the label. 


How long will the tiny black bumps take to sprout leaves?

The bumps or spots will sprout leaves in 2-3 weeks after their appearance. If this does not happen, you should consider fixing the light or nutrient content. 


How often should you change the aquarium water to keep the Java Fern healthy?

Refresh the water every 14 days to get rid of extra nutrients and fish waste. Replacing 100% of the water in the tank is not necessary; 10-25% is enough for the healthy growth of aquatic plants and fishes in the aquarium. 



If you find aquarium plants difficult to grow, you should give a try to this fern variety. 

It has no special light or substrate requirements and requires little maintenance. 

You can regularly prune the Java Fern to keep it small and neat. If you want a bushy jungle in your tank, you can allow the foliage to grow.