How to Grow Java Fern in A Fish Tank
By Eddie Waithaka @aquariawise
Java fern is one of the most popular plants used in aquascaping freshwater fish tanks. It.s especially loved for its fairly subtle growth, unique leaf structure, and easy propagation. The plant also tolerates a range of lighting conditions and water parameters from acidic to alkaline and even brackish tanks.
The plant is easy to find in pet stores though it has several cultivars which include narrow leaf, windelov, trident, and needle leaf variants.
Star your Java fern in a tank with the water temperature anywhere from 60°F to 83°F and a ph from 6 to 7.5. Cultivate new plants by tying the plant’s rhizomes to rocks or driftwood instead of planting it in the substrate directly.
Java fern will grow in tap water in dim or bright light and with or without gravel. Plus it’s quite snail-tolerant and grows best with higher-fish.
A great benefit to this plant is that it does not require a substrate, making Java Fern idea for bare bottom tanks.
That said, this article will help you understand everything you need to know about Java fern in aquariums from the types available in the market, how to grow it to caring, propagating and more.
Java Fern Overview
Java fern is scientifically identified as Microsorum Pteropus and is native to South East Asia from the Java Islands of Indonesia in the South to Malaysia and Thailand in the North. And as far west as Northeast India.
The plant is also found in parts of China, Taiwan and Japan.
The fern is a highly variable species with several variants that vary in leaf size and shape. Nonetheless, all variants grow both fully or partially submerged which means it can grow with the leaves partly out of water.
In the wild, Java fern usually grow on roots of other plants or anchored on river rocks through rhizomes which look like roots. The growth is such that old leaves get tall and die, then new foliage readily replaces them to keep the plant lush.
The false roots are also used as nutrient carriers for the plant. They are mostly dark-brown and hair-like, wherein aquariums they’ll develop attached to driftwood or rocks.
This lets Java fern spread and branch-out to cover a wider area around the fish tank though this could take quite a while because this plant is generally slow growing.
By and large, Java fern will grow in tanks as small as 10-gallons and up to 55-gallons or more with soft to moderate water. Depending on the size of your aquarium, you can either use your plant as a mid or background plant.
Java Fern Types
As I mentioned, Java fern is a highly variable plant with several popular types available in the aquarium plants market.
Let’s see 7Java fern forms common in fish stores over and above the standard type.
Java Fern Narrow Leaf
This variant is a great low light type that is quite hardy and similar to regular Java fern albeit having thinner leaves which create a bushy-effect in the fish tank.
Buy narrow leaf Java fern with 4-leaves (or more), which once started, will grow into a focal point even among other aquarium plants.
One pro of this type of Java fern is it’s bright green leaves that are important in aquariums since they provide plenty of feeding area for shrimp and fish.
Narrow leaf Java fern requires low to moderate lighting and nutrient-rich water and growth rate is also improved by C02 injection.
This plant is native to South East Asia cultivated particularly in Taiwan nurseries.
Java Fern Windelov
This variant is a unique species of Java fern with interesting tops that have pom-pom like bushes on the leaves.
Windelov is equally as hardy as any other species and will grow in both low and high light aquariums though it will have subtle differences given the light conditions.
In low light, windelov Java fern develop wider leaves and smaller bushes while in high light, plants tend to be elongated and with less foliage.
This species is a created form from cross-breeding of other Java fern types.
Java Fern Trident
This variant of Java fern has very distinctive trident formations on its leaves instead of the straight, broad leaves of the standard type.
Caring for trident Java fern is however same to other species and should be attached to aquarium decor. It also requires low to moderate light and will thrive in a variety of water parameters.
Trident Java fern grows to between 4 and 8 inches in height, and it’s particularly suited in aquariums when used as a mid-ground plant.
Needle Leaf Java Fern
Needle leaf Java fern is a variant with extremely-narrow ribbon-shaped leaves with dense, bushy growth. The leaves are also more dark-green than some other forms.
However, true needle leaf fern is relatively rare in the hobby and quite hard to come by in trade.
The leaves on this species grow to less than an inch wide and approximately 4 to 8 inches tall. It’s a relatively slow grower which makes it suitable for nano aquariums.
It is common for Taiwan narrow leaf to be called needle leaf in the hobby though it’s not a true needle form because of its wider, longer leaves.
Taiwan Narrow Leaf Java Fern
This type looks a lot like needle leaf Java fern only with wider, longer leaves.
Taiwan narrow fern leaves have the same structure as needle-leaf fern which are ribbon-shaped, long and fairly narrow. Think of it as a bigger needle-leaf version.
Mini Java Fern
Java fern narrow mini is a small hybrid cross between the standard Java fern and Java fern needle leaf.
The leaves are thinner than the regular type at about 0.5 inches wide but not as thin as needle leaf.
However, planting and caring in aquariums is fairly much the same as any other type.
Java Fern Phillipine
Phillipine Java fern has nicely hammered leaves that are slightly thinner than regular Java fern. However, the form is widely considered a leaved fern as opposed to a narrow leaf variant. The plant leaves are also unique and heavily textured.
This Java fern variety was introduced by the Danish nursery Tropica, same as Windelov, and has gradually found favor from aquarists everywhere.
Should Java Fern be Planted? (How to Start Java Fern)
Java fern does not do well when planted in the substrate and will grow slowly or die off especially when the rhizomes are buried completely.
Instead, your plant will do best when tied on driftwood or porous rocks like lava rock using threads, fishing line or super glue.
The thread or fishing line will firmly anchor the plant onto the surface until its fully attached which usually happens after a couple of weeks. You should also consider using degradable threads that will rot after the plant is firmly fastened to reduce the hustle of removing the line.
Should you choose to plant your Java fern in the substrate, the one thing to watch out for is that you don’t bury the roots because that is where roots and leaves extend out. If you bury them under gravel or sand, they will rot instead of growing.
How to Attach Java Fern on Driftwood or Rocks
There are a couple of methods you can use to tie Java fern to rock or driftwood, from using fishing line, threads to using super glue with all serving the same purpose albeit a barely different.
Generally, tying your Java fern using fishing line or threads is the more popular and simpler method. You only need to choose a spot on the rock or driftwood and attach the plant bottom part of the plant on top of your rock or wood.
Java fern is best attached from the spot where roots meet the rhizome to allow the plant to spread evenly while still anchored.
To attach your plant using super glue, take the piece of decor you want the plant to attach to and make a simple bead of glue. Hold the plant against the glue for 30 seconds and let it dry for another 3 minutes before you place it in the tank.
How to Grow Java Fern Fast
The first hack for growing Java moss fast is to avoid placing it in a substrate but attach the rhizomes on driftwood to make sure the plant spread more and within a short time.
In low light, it may take a while before Java fern gets going, so you will need moderate to high light for faster growth. However, more light will also mean more algae to deal with, plus your plant will grow taller with fewer leaves.
In case your fish tank is a high-tech setup, you can try to hasten the Java fern growth by adding extra fertilizer and CO2 especially when you have many plants.
That said, Java fern will grow slower when put in a tank with many plants because the nutrients from fish waste and hard water are not enough and fast-growing aquarium plants will hog on the few nutrients available.
How Do You Take Care of Java Fern?
When it comes to growing, you don’t need expert skill level to pull off a perfect Java fern job. The planting and care needs are quite straight forward, and the only thing you may need to be concerned about is lighting and maybe dosing.
Java Fern Lighting
Almost any light will do in a tank planted with Java fern. The plant is not picky and accepts a wide range of the light spectrum and number of watts.
However, the plant will do best when provided with a range from low to medium-high light. Start it under 15 watts of light per gallon of water from a bulb with the spectrum range anywhere from 5000K to 7000K.
If you decide to put your aquarium in a spot with ample sunlight, make sure your Java fern get between 8 and 12 hours of light a day.
A thing to note is that all aquarium plants require a period of darkness to rest and replenish. Therefore, turn off your fish tank lights after a 12-hour interval and let them stay off for an equal duration.
Fertilizer and CO2 Addition
Although Java fern doesn’t need a lot of fertilizer to keep the plant healthy, you may have to add some liquid fertilizer to restore nutrients in case of deficiency in a heavily planted fish tank.
This will help your plant, which is slow-growing, and unable to compete for nutrients with faster plants like hornwort.
Use liquid fertilizer if you don’t notice any growth a few weeks or months after you add Java fern in your aquarium. Ideally, go with a liquid type fertilizer with iron supplements to help your plant maintain its color as it develops.
Also look out in case your Java fern starts turning drab-olive then brown which a classic sign of a nutrients deficiency.
Java fern will do without carbon dioxide addition hence any dosing effort you make in your tank won’t serve any other crucial purpose other than boosting your plant.
Java Fern Tankmates
Java fern is hardy hence compatible with a huge variety of fish and is even resistant to most snails that nibble on other aquarium plants.
Also, most herbivorous fish that would normally eat live plants tend to stay away from Java fern because it’s tough and unappealing.
The only parts of the plant you would need to worry about are the roots especially in younger Java fern plants because they tend to be tender. So keep an eye out every once a while until the plants are fairly hardy.
Moreover, with younger plants you’ll want algae eaters and sucker fish to ensure algae doesn’t out-compete your Java fern for nutrients.
In case you are having a serious algae problem on your plants, take some leaves and start them in a different tank or a container with water and access to light. Once they start to develop, reintroduce them in the tank to form new plants with no algae.
Java Fern Propagation
Propagating Java fern is easy, sometimes all it takes is throwing the plant in your water, and the plant will start growing. As long as it’s floating or attached to driftwood or rocks, the plant will grow.
To start new Java fern plants, you can either cut the rhizome in half and replant the cutting or develop the new plant from young leaves that develop under older leaves.
The young leaves usually start as black-spots on a mature plant.
New plants from propagates should start showing signs of growth 2 to 3 weeks after introduction to a fish tank. Just remember to tie the new plant to make it firm and give it ample area to spread.