Java Fern: Care & Propagation Guide

Java Fern (Ceratophyllum demersum) is a slow growing aquarium plant used by many fish breeders. This plant is super easy to care for and is a great beginner-friendly plant. 

This slow-growing plant is used by many famous aquarists in their aquascapes which made the plant even more famous. Its beautiful lush green leaves and its unique reproduction method make them a very desirable plant for most aquarium owners. 

Yes, this plant is hardy; however, you will need to know and follow the care requirements it needs to experience its full beauty in your tanks. So we made this guide to walk you through all the information you need about this plant. So let’s get to it!

Overview

Java Fern is natively grown in multiple countries in South Asia. The vast majority of them can be found on the Indonesian island of Java. But are also found in Malaysia, Northeast India, Thailand, and some parts of China.

Because large populations of Java Fern are found around Java Island it becomes famous as “Java ” Fern. In the wild, this plant grows on rocks and hard objects in highly humid areas. It can grow both in and out of the water which makes them one of the hardiest plants. 

As said, Java Ferns grow in several geographic areas but they seem to prefer to live in areas that have more rocks. They are usually found attached to rocks in areas where water can raise or go down throughout the year. 

Appearance

Java Fern (Ceratophyllum demersum)

Java Fern has tall arrow-shaped leaves that are growing directly out of a central rhizome. But, depending on the area this plant grows in the wild, it can have slightly different leaf shapes and sizes. 

This plant is made of three main components. They are made of large leaves, the rhizome, and their thin dark brown roots. The rhizome is a stalk that the leaves are attached to. The roots are only used as anchors to hold the plant on the rocks and objects and not for absorbing nutrients. 

Java Ferns are not flowering plants and only grow leaves and rhizomes. The leaves are lush green but the rhizome is usually dark brown, the same as the roots. The strength of the light in your tank can make this plant become darker or brighter green. 

The most common types of java ferns are Narrow-leaf Java Fern, Needle-leaf Java fern, Windelov Java fern, and Trident Java fern. The names are pretty explanatory of the leaf shapes these plants have and they all share the same care requirements. 

Size & Growth Rate

Some varieties of Java Ferns can grow up to 14 inches. However, they are very slow-growing species and can take some time before they can reach this size.

Their size depends on the type of Java fern you have. Some varieties of java ferns will only grow to a few inches which makes them great midground plants. Here are the most famous Java ferns and their size:

  • Narrow-leaf Java fern: 12 inches.
  • Needle leaf Java fern: 6 inches.
  • Trident Java fern: 5 inches.
  • Windelov Java fern: 8 inches.  

Java Fern Care

Java Fern care is super easy as this plant can grow in a wide range of water parameters. Because of this, they are among the most beginner-friendly plants in the aquarium hobby. They can survive the harsh environments that can happen in a tank without showing any signs of stress.

However, they can only survive unhealthy environments in the short term and need proper water conditions to be able to thrive. 

Tank Size

Java Fern is a tall plant so you will need to place them in tall tanks. While most online resources say 10 gallons is the minimum tank requirement for java fern. We believe they need at least a 20-gallon tall tank or bigger. This is because almost all 10-gallon aquariums are short and can not provide the java fern with enough vertical growing space. 

We have placed java ferns in different sizes of tanks and we found they grow bigger and better in larger tanks. The gallons a tank can hold are not that important, instead, you should only get java ferns if you have a tall tank. 

Water Conditions 

Java Ferns are hardy aquatic plants that can live in most tank environments. They, however, need a decent source of light to be able to photosynthesize naturally. When tank parameters are in their favor and they receive enough nutrients and light they will continue to grow new leaves and grow bigger.

A good aquarium filter and a decent amount of water current are necessary for these ferns to be able to grow. The tank’s filter will process the fish waste and make them ready for the fern to absorb. But because Java ferns are slow-growing species, algae might grow on their leaves. A slow to moderate current will help you reduce the chances of algae growth on this plant’s leaves. 

While Java Ferns can survive a wide range of water parameters, they can only thrive in the following range of water parameters:

  • Temperature: 70 – 80 Degrees Fahrenheit 
  • PH: 6 – 7.5
  • TDS: 30 – 200 PPM

CO2 Requirement

Java Ferns are hardy plants and can grow without CO2. However, they will grow much better when they receive CO2. The leaves will grow faster and become more vibrant when CO2 is injected into the water. 

Lighting

Java Fern can live in any lighting conditions. Under low light, this plant can survive but might not grow as fast and tall as it might under strong lighting. But you need to make sure the light source is not close to the plant as it might burn and melt the plant. 

A 6700k spectrum light source is great for java ferns in a planted tank. You can leave the light on for 6 – 12 hours depending on the nutrition levels available in your aquarium. 

Substrate

Java ferns do not need planted substrate. They live on rocks and driftwoods and absorb nutrition from the leaves and not their roots. 

Java Fern (Ceratophyllum demersum)

Planting & Placement

Java Ferns are midground to background plants. Larger variants of java ferns should be placed in the background so they don’t block the view of your tank. You can attach them to rock and driftwoods and place them in the background. 

You should never plant java ferns in the substrate. The rhizome of the plant has to be above the substrate at all times or the plant will die. The rhizome and roots will rot if they don’t receive light. 

Java Fern Propagation

This plant naturally propagates in a very unique way. When leaves are fully grown and mature, they will start to grow small black dots on themselves. These black dots will then become tiny new plants and start growing on themselves.  

This is their natural way of propagation but you can also propagate them by cutting the rhizome. When the plant is grown and has at least 10 leaves you can cut the rhizome in the middle leaving 5 leaves on each side. The new cuttings will continue to grow and grow new leaves. 

When cutting the rhizome make sure to use a sharp blade. The rhizome should not be crushed as it will start to rot and the plant might die.

Maintenance & Fertilization

Java Fern is a slow-growing plant. This means less trimming and maintenance time for you. However, Java fern can melt if the tank conditions are not in their favor long term. If you see leaves breaking or turning yellow it’s a sign for you to check everything in your setup. 

If this happens you will first need to check if the plant has enough fertilizer or not. They can also start to melt if the light is harsh. So first resolve the cause and then cut the dying leaves. 

It is important to find the right fertilizer and light balance for your tank. When there is an imbalance in the tank, many problems including plant dieoff and algae growth can occur. Adding liquid fertilizer can help ferns to thrive if there is not enough fish waste in the tank. 

But Java ferns do not need fertilizer if there is enough fish in the tank. 

To keep your java fern fresh looking, you might need to remove some of the dead or dying leaves from time to time. When you are doing your water changes, you can cut the dead leaves with sharp scissors close to the rhizome and remove the leaves from the tank. The good news is that jer leaves will float to the surface of the tank which makes cleaning easy.  

Tank Mates

The Java Fern is a hardy plant that can live with most fish and plants. Almost all South American and Asian fish can live in harmony with java ferns in their tanks. As long as you fish and this plant shares the same water parameters you can house them together without any issues. 

However, some fish might disturb the plants so you should avoid placing java fern with those fish. African cichlids and goldfish, and koi fish are some of the best tank mates you might want to avoid if you are not an experienced plant and fish keeper. 

Here are our top pics of ideal tank mates for Java Ferns:

Benefits of Java Fern in Aquariums

Java Fern is a hardy plant that can tolerate a wide range of parameters. This makes them a great plant for most aquariums to remove fish waste and make the tank look good. You can create beautiful aquascapes using this plant and give your aquarium some life. When conditions are in favor of your java fern, they will create dense jungle-like scenes in your tank. 

At the same time, they will provide lots of hiding spots for your fish and any smaller creatures that you might have in your tank. If you have fish that breed, this plant can keep some of the fry safes until they grow.

Java Fern (Ceratophyllum demersum)

Conclusion

Java Fern is a beautiful freshwater aquarium plant that is easy to care for. They are one of the most beginner-friendly plants someone can start with. This plant is widely available in most pet stores and online. 

The main point of attraction for this plant is its beautiful and tall leaves as well as its low price range. They are usually sold very cheap which makes them super affordable for first-time plant keepers. 

We tried to answer all your questions regarding java ferns in this article. If you still have questions to ask please reach out to us by email. We will happily help you and update this guide to help others.