Java fern is well known as a great hardy option for all kinds of different aquarium environments, but does it need to be under the surface to survive? Can Java fern grow out of water?
Although it is often thought of as an underwater plant, Java fern can be grown outside of the water as well if you know what you’re doing. It can survive when fully submerged, partially underwater, or above the surface.
Read ahead to find out everything you need to know about growing this incredible fern and keeping it healthy without submerging it!
Can Java Fern Grow Out Of Water?
If you know anything about Java fern, then you are probably aware that it absolutely loves the water. These plants are a favorite among aquarium owners as a place for fish to hide and explore inside of their tanks, but they don’t have to be grown under the surface.
It might surprise you, but a Java fern can be grown out of the water (otherwise known as “emersed”) – as long as it is kept under the right conditions!
Actually, the Java fern is not very picky about where it grows. It can be completely under the water for its entire life, it can be partially submerged, or it can live happily with its leaves completely out in the open.
Many Java ferns will naturally extend their leaves above the surface as they grow simply because they can. The bigger they are, the further they will stretch – you might even find yourself trimming them down to keep them in the aquarium!
Does Java Fern Need To Be Submerged?
A Java fern does not need to be submerged to survive and thrive.
We tend to think of plants as suitable for growing either under or above water. If you place most aquarium plants in the fresh air, they tend to die pretty quickly, but this is not true of the Java fern. It is a very accommodating and adaptable plant that has learned to survive under a variety of different conditions.
It’s one of the reasons why Java ferns have become such a favorite within the aquarium hobby. It’s not just an attractive decoration – it’s a survivor. There are very few tanks that a Java plant won’t be happy in!
It can live under low or bright light conditions, it is fine with or without gravel, and it can even handle basic tap water.

How Long Can Java Fern Live Without Water?
Although your Java fern can grow perfectly happily outside of the water, that does not mean that it can live without water entirely. Actually, it will still need a lot of moisture and humidity, and its roots and the base of the plant should be kept in constant contact with water of some kind.
Without any water at all, the fern will start to dehydrate, and it will likely start to die within a day or so. How long it survives will depend on how much moisture the plant still has access to. If the humidity is high enough, a fern can survive for quite a long time as long as the base stays wet.
If you take a Java fern that was previously submerged completely out of the water while moving things around in the tank, then it will likely be fine without water for a couple of hours before being placed underwater again.
It is possible to move a Java fern from a submerged environment to an emersed environment, but it will often shed its underwater leaves before growing new ones.

How To Grow Java Fern Out Of Water
So, we know that a Java fern can be grown out of the water, but how do you actually go about doing it? Well, there are some important tips that need to be followed if you want your Java to stay happy and healthy without being submerged.
Start With A New Plant
It’s always best to start off with a relatively young fern because they will be more likely to adapt to a slightly different environment without experiencing shock. A 3” to 4” Java is best – they usually come in a small pot, ready to be transferred to their new home.
Select An Appropriate Base
These plants don’t grow in soil, and they need a strong base to attach themselves to. You might use driftwood or rocks, but make sure to choose something that can have a consistently wet surface. Think about how you are going to position your fern’s base so that it will be in contact with water all of the time.
Choose A Placement Point
You will need to situate your Java fern in a place where it is secure and comfortable, so choose a point on your rock or wood carefully. Natural crevices and divots are good options as they will keep the plant relatively stable while it is attaching itself.
Identify The Rhizome
The rhizome is really important when it comes to making sure your Java fern is growing properly. This is a special part of the stem from which your plant will send out new roots, and it needs to be touching the water at all times.
It’s easy to find. The rhizome will be at the base of the plant, and all of the leaves and roots will originate from it.
Secure The Plant In Place
There are several ways to actually attach your plant to its new home. You might use twine, rope, fishing line, or a rubber band, but a thin layer of super glue gel is best. Not just any glue will do, though. It should contain cyanoacrylate and be a version that is safe for plants. Make sure to dry the roots and rhizome off before sticking it in place!
Keep The Base Wet
This is the most essential part of growing your Java fern out of water. The roots and rhizome need to be in contact with water all of the time, even if the rest of the plant isn’t.
A simple way to achieve this is to keep the base (with the rhizome and roots attached) completely submerged so that they will never dry out. You might, however, try something else – like having water gently cascading over the base or greatly increasing the humidity so that there are always droplets on the roots and rhizome.
Keep Things Humid
Whether your rhizome is fully submerged or not, you need to keep a high level of humidity for your Java fern to be happy. This might include regular misting to make sure that the leaves are as healthy as they can be at all times.
Recap
So, can Java fern grow out of water? It certainly can! This fern is an incredibly adaptable and forgiving plant, and it can grow completely underwater, partially submerged, or completely in the air – as long as its base stays wet.
Java ferns are a great choice for almost any kind of aquarium for just this reason. You can almost place them anywhere.
The most important thing to remember, however, is that their roots and rhizome will still need to be in constant contact with the water. This means that you typically need to submerge the base your fern is attached to, but there are other ways to achieve this too.