The Java Fern is one of the most popular freshwater plants.
They are well know for their hardiness and ability to thrive in low light environments.
While they are not a particularly large plant, their elegant appearance makes up for it. They grow in dense clusters which are used to create shrubs and hedges for your aquascape.
You can grow Java Fern in just about any kind of freshwater environment and your fish are sure to love it.
Keep reading to learn all about their care requirements…
Table of Contents
Overview and History
The Java Fern is known as both Microsorum pteropus and Leptochilus pteropus and comes from the Polypodiaceae family of ferns.
They are named after the island of Java in Indonesia and are commonly found throughout Southeast Asia.
You can find several different variants of this plant, including: needle leaf, narrow leaf, trident and the windelov.
This fern is used in lots of different ways but most people use them to create a low lying shrub or hedge. Another popular way to plant them is in the background where it can grow to its full height of 13 inches.
It makes a great shelter for fish and invertebrates that like to hide under plants and can also be used as a nest for those that spawn on leaves. Not only does this plant provide good shelter it also help improves water quality. This plant’s large leaves can add extra oxygen to the water during photosynthesis.
The plant was introduced to the aquarium trade in 1929 and since then has continued to gain popularity. This popularity is because they are extraordinarily easy to care for and highly recommended for beginners.
You will find this plant just about anywhere that you can buy aquarium plants.
Expect to pay $4-$10 per plant.
Java Fern Care Sheet
Whether this is your first aquarium or your fiftieth, this plant should give you no trouble at all.
With just a little bit of care and patience, a single crop can bloom into an elegant underwater garden!
You will need at least a 10 gallon aquarium to keep Java Fern.
If you have multiple crops then you may want to use a 20 gallon tank.
The water temperature can be as low as 68°F or as high as 82°F. However somewhere in the mid-70s is ideal. It should be very soft (between 3 and 10 dGH) and the pH should range from 6.0-7.0. Make sure that there is very little turbidity and no accumulation of waste in your water.
Thanks to their large leaves and strong rhizomes, they are able to buffer currents. They can withstand a moderate flow from an undergravel or hang on back filter. It never hurts to add a little bit of oxygen to your water column too. You can use an air stone or a light air pump.
The type of substrate does not matter as this plant does not grow rooted in substrate. What is more important is that you have rocks or thick pieces of wood to attach them to. Make sure to leave plenty of space for their leaves to grow to their full width.
Because this plant is used to growing in shaded areas in swamps and jungles, it does not handle strong light very well and should never be exposed to direct sunlight. You only need between 1.5-3 watts of light per gallon for it to grow. You should not use a light intensity over 4 watts per gallon.
How To Plant
You might be used to growing plants in the substrate, but that will not work for Java Fern.
It can only be grown anchored to hard surfaces.
Rough rocks are the best surfaces to use, but you can also use driftwood, or a rough mineral surface. Smooth pebbles and glass are not going to work.
Set the plant down on your chosen surface and spread the rhizomes out. Then, tie the rhizomes down and wait for them to take hold. If you cannot find fishing wire then you can use thick twine or rubber bands. Never try to glue the plant down.
It will take around two weeks for the rhizomes to take hold. Once they are secure you can cut away the fishing wire.
Care and Maintenance
Although this plant grows slowly, it can shade out all of the other plants in your tank if allowed to grow out of control.
Their slow growth rate means that it will need less maintenance than most of your other plants.
You will only need to trim it every month or so.
Use a small pair of pruning shears to snip away the offshoots that grow close to the rhizome. You should also trim away any leaves that are beginning to wither, rot, or turn brown. These can foul your water quality and leaf rot can spread to the rest of your plant.
One of the very best things about Java Fern is that it can grow in very little light.
This plant can still grow in less than 3 watts per gallon so it is considered a low light plant.
Although this plant can grow in 1.5 watts per gallon, you should aim for 2 to 3 watts per gallon.
To find the best aquarium bulb you should divide the amount of water in your tank by your light intensity in watts per gallon. For example, a 15 gallon tank running at 3 watts per gallon will need a 5 watt bulb.
In low light the leaves will become a very bright green color, but in higher light intensities the leaves will darken.
No matter which intensity you use your plant should have at least 6 hours of light exposure every day.
Just as a reminder too you should not expose the plant to direct sunlight or it may dry out or become sunburned. A sunburned plant has black or brown marks over their leaves.
Appearance, Colors and Types
The Java Fern is a beautiful green fern with blade shaped leaves.
In total there are 4 different varieties, and with the exception of the narrow leaf variety, they are specially cultivated for aquariums and do not occur in the wild.
- Narrow Leaf Java Fern is the most common. This variety has sword shaped leaves that can grow up to 8 inches thick and the plant itself can grow up to 13 inches high.
- A Needle Leaf Java Fern is a miniature variety. Their thin leaves grow up to 3 inches thick and the plant only grows up to 6 inches high.
- The Trident Java Fern has up to 5 branching leaves on a single stalk. It reaches about the same height as the narrow leaf variety, but their leaves are not quite as thick.
- Finally, there is the eclectic looking Windelov Java Fern. This fern grows up to 8 inches high and has thick leaves that branch off at the tips.
Java Fern comes in many different shades of green, from lime to deep emerald.
The color depends on how much light you give them. In light intensities under 3 watts per gallon, the plant will take on shades of bright green. In 3-4 watts per gallon your plant will take on darker shades of emerald and forest green.
Their leaves grow together in dense clusters, so this plant grows wider before it gets taller.
Unlike many other aquarium plants, this plant does not have a true root system. Instead it has wiry rhizomes that attach to hard surfaces. The plant grows up from the rhizome when it finds a suitable surface to anchor down to.
New offshoots (called daughter plants) grow directly from the rhizome. You can cut the daughter plants off from the parent plant and propagate them to grow brand new plants.
Size and Growth Rate
Young Java Fern are usually sold at between 3 and 5 inches high.
Your plant will grow about an inch every month and it can take up to a year to reach its full height of 6-13 inches.
Every week you should see at least one new leaf appear on your existing cluster. These leaves will get thicker until they reach 8 inch wide.
You can speed up the growing process by adding CO2 fertilizers and raising the light intensity above 2 watts per gallon.
With several varieties available there are plenty of different ways to grow this fantastic fern in your aquarium.
Most aquascapers place this fern in the middle layers – this is where you will naturally find it in the wild. In the foreground it will take up too much space and shade out the other plants in your tank.
Windelov and Needle Leaf varieties are the best for growing hedge formations along the edges of your tank. In a paludarium you can also grow the plant emersed along the water’s edge. However, this is not a free-floating plant so you will still need to anchor it to a surface below the water.
Since this Fern will grow anchored to rocks and other decorations in your tank you can place it wherever you place your decorations. Just make sure to leave enough room for your fish and other plants.
Compatibility and Tank Mates
There are very few fish that this plant is not compatible with.
Java Fern’s strong rhizomes let them stand up to even the most boisterous fish. Also because this plant does not grow in the substrate, it cannot be uprooted by fish that dig and burrow.
This fern also makes an excellent accent to the homes of small livebearing fish, including Guppies and Swordtails. In a warm-temperate tank it is great for Goldfish and Mountain Minnows.
At the bottom of the tank Cory and Pictus Catfish use the plant as a hideaway. It is also much appreciated by larger bottom dwellers like the Plecostomus.
Cichlids are known for digging and uprooting plants but the hardy Java Fern is considered one of the safest plants for Cichlid tanks. Even the boisterous Oscar will not give it any trouble!
Fish are not the only critters that benefit from these plants. They are excellent for Vampire Shrimp, Nerite Snails, and Mystery Snails.
In a paludarium, small newts, skinks and frogs can use the plant as a hideout. These docile critters will not harm the fern at all.
This is one of the easiest plants to propagate.
It is grown using offshoots from the rhizome called daughter plants.
The daughter plants add more density to a single plant and create new plants when cut off and planted in another spot in the tank.
Watch the rhizome or the stems for the formation of new daughter plants. Tiny black spots under the leaves indicate that new plants are about to grow in. After about 2 or 3 weeks the daughter plants should have reached about 3 inches in height.
You can then safely cut them off and propagate them.
Gently snip them from the base of the stem and anchor their rhizomes to another surface in your tank. Remember that you will need to tie them down just like with your first plant.
In 2 weeks your new plants will have taken hold and will begin to produce daughter plants of their own. You can propagate these and start the process all over again.
You can also create new plants by cutting the rhizomes in half or dividing them into segments. Each segment will produce a new crop when anchored to a surface.
Java Fern grows very well on their own and do not need any CO2 or fertilizer.
FAQs About Java Fern
Where should I put my Java fern in my aquarium?
This plant looks its best in the middle layers or along the edges of your aquascape.
You should place it in the areas of your tank where the light penetration is not too strong.
How many hours of light does Java fern?
Your Java Fern will need exposure to at least 6 hours of light per day.
However it should not be exposed to light for more than 12 hours a day.
If you run an intensity below 3 watts per gallon you can leave the lights on for a few hours longer than you could at a higher light intensity.
Why is my java fern turning brown?
There are several reasons why your fern could be turning brown. The most likely reason is that they are not getting the correct nutrition. Try giving your plant a bit of fertilizer and see if there is an improvement. If not, adjust your light intensity or move the plant to a shadier part of the tank.
My java fern has black spots?
Do not be concerned if you see tiny black spots appear on your plant. Within a week, new plants will grow from these spotted areas. If the black spots are growing larger, however, your plant may be sunburned. Turn down your light intensity or move the plant to the shade.
Why will my java fern not take root?
If it has been over a week and the rhizomes have still not taken hold then there may be a problem with the surface you are trying to grow it on. This plant will not attach to soft, smooth surfaces like pebbles, glass or plastic. Try to replant the fern on rock or natural wood and make sure that it is tied down tight.
The Java Fern offers a world of possibilities for your aquascape.
It is compatible with almost every popular freshwater fish and is an excellent choice for new aquascapers to start off with.
Not only does this plant look beautiful but it oxygenates the water as it undergoes photosynthesis. Their lovely wide leaves will also buff the water flow and shelter your fish and invertebrates.
It is so easy to grow that you will not need to worry about buying new plants. In the right light and water conditions, this plant will raise itself.
Overall this is a fabulous fern.
Why do you like Java Fern? Let us know in the comments section below…