Can Ferns Survive Underwater? 9 Things To Know

Ferns are one of the longest-living plants on earth. These epiphytic plants have been around for roughly 350 million years–millions of centuries older than humankind. Ferns have undergone several evolutions to continuously adapt to their changing surroundings, which is why they’ve survived this long. 

Many ferns can survive underwater almost indefinitely. Provided they have access to sunlight, specific humidity levels, and adequate nutrients, ferns can grow in water either fully submerged or with their leaves sticking out.

In this article, I’ll cover several things you need to know about ferns and their ability to survive underwater. 

Things to Know About Growing Ferns Underwater

Although most ferns can grow underwater, it’s important to note that this feature is a constant among all species of ferns. 

Also, even among ferns that can be grown underwater, there are quite a few things to be aware of. Factors like sunlight, placement, growing method, and much more are all critical if you plan to grow your ferns this way, and it’s vital to know how to account for them.

Regardless, growing ferns underwater can eliminate a lot of the stress of watering and is an excellent practice if you get it right. 

Here’s what you need to know:

1. Ferns Can Grow Without Soil

Many ferns can grow without soil, provided you meet their other conditions. These additional conditions include the provision of an aggregate alongside, such as rock, clay, or even pebbles and hydroculture fertilizer. 

Growing your fern plant in this way is known as hydroculture. Many people choose to grow them this way because of the fern’s many requirements, including frequent watering, specific humidity levels, and the frequent provision of mineral nutrients.

As you might expect, providing these plants with all these conditions could be tricky, especially if you have a busy lifestyle. Growing these plants using hydroculture solves this problem. Submerging them in a mineral nutrient solution eliminates the need for any soil.

2. Some Ferns Grow Better Than Others in Water

There are several types of ferns; some are better at growing in a hydroponic setting than others. Cinnamon ferns, royal ferns, sensitive ferns, and painted ferns are all water-loving ferns that will survive and thrive when you fully submerge them in a water solution. 

On the other hand, some ferns like Christmas and wood ferns will not survive underwater. If you decide to do it anyway, you may realize that these ferns will begin to droop. Additionally, their roots will start to thin out and eventually die.

For ferns like the Christmas and wood fern, you should plant in well-draining soil and water regularly instead. Also, ensure that the soil you’re providing has rich organic matter. Do this, and your fern should be fine.

So, before submerging your fern entirely in water, ensure it’s well-suited to it. Some other ferns that can survive well include the Asparagus fern, the Boston fern–the most common among plant lovers–and the Java Fern.

3. Submerging in Water Keeps Pests Away

Pests attack plants of all shapes, sizes, and forms. As long as there’s organic matter, pests want to attack and feed on it. Luckily, submerging your ferns in water helps to prevent this from happening.

Very few pests like to go for plants partially or fully submerged in water, so this is a smart move if you have a pest problem. The water will serve as a vast line of defense, a pest control barrier that prevents all types of plant pests from sucking up its nutrients. This will allow your fern to survive underwater with minimal precautions against pests.

To further prevent pest infestations, I recommend you use insecticides. Pest control barriers will act as the first line of defense against pests, and insecticides will finish the job. 

4. You Can Fully Submerge or Leave Its Leaves Above Water

Ferns can thrive with partial or complete submersion in water. Realistically though, many horticulturists and plant lovers would prefer to leave the plant’s leaves outside.

If you want to entirely submerge your fern in the water, it’s best to go for a clear container with some gravel added to cover the roots. Leave the leaves untouched and don’t cover the container so its leaves can get direct sunlight.

However, if you want to leave your epiphyte plant’s leaves outside, I recommend you find a hydroculture pot. With some repurposing, you should easily be able to turn your standard indoor houseplant pot into a hydroculture one. You could even place ferns in fish tanks!

For partial submersion in water, you must add some aggregate. Gravel or clay aggregates are the most helpful for fern roots. Ensure the leaves are well above water and optionally add a cover to prevent the water from spilling by accident.

Over time, you would notice that the water level is reducing. Sure, you can monitor the water level manually, but it’s best to use a water level monitoring device for efficiency and accuracy.

5. Ferns Require High Humidity Levels

Ferns love and will grow best in highly humid air. That’s why you see many ferns growing in tropical regions. If you want to see a diverse amount of ferns in all their glory, take a trip to tropical rainforests.

Tropical rainforests regularly have humidity levels above 70%. Consequently, many ferns cannot grow in regions of low humidity. If you want your fern to have a chance at survival, you have to ensure the air’s humidity levels are high. 

Very few ferns can survive in humidity levels lower than 30%. A decent humidifier can raise humidity levels to around 50%.

Although this level isn’t the best for ferns, it should be fine for most of your plants. Some humidifiers even offer higher humidity percentages but might cost you slightly more. If you keep the air surrounding your fern humid, it will survive and thrive in water.

6. Ferns Need Sunlight

Without healthy exposure to sunlight every day, your fern’s chance at survival underwater becomes slim. No matter what fern you want to place underwater, they all have one thing in common: they need sunlight to grow.

However, ensure that the intensity of the sunlight is low. Many types of ferns don’t do well in direct sunlight. Their fronds will get burned and may turn brown when exposed continuously. 

The safest way to give these ferns sunlight is to provide them with indirect sunlight. All you need to do for indoor fern plants is put these long-living plants near windows that bring in a decent amount of light but ensure you keep them away from direct rays.

Without this, ferns can survive in low-light conditions as long as it’s constant. Whatever you do, don’t let direct light hit your fern. If this happens, you will end up with a dry, crispy plant.

7. They Grow Best in Hydroponic Net Pots

Hydroponic net pots are pots with a net framework that many horticulturists use in a hydroponic system. These net pots efficiently support plants without soil. 

Hydroponic net pots will significantly improve root and leaf growth and overall plant development without the presence of soil. Nutrients and moisture will be quickly gained and lost due to the many holes in these net pots.

So, if you’re looking for the best pots to facilitate your fern’s growth, hydroponic net pots are your best option. You could even create a hydroponic system for your fern.

8. Adequate Aftercare Is Required

While ferns can thrive with minimal care, entirely neglecting them would pose a problem. For starters, you need to make sure that the water levels stay at an optimal level. 

It’s also vital to replace all the water in the tank rather than simply topping it off. This will significantly reduce the possibility of algae growth.

Next, make sure you clean out the pot or tank bi-monthly to prevent mold buildup. Carefully remove the fern, clean the pot, fill it with fresh water, and place the plant back inside.

Finally, always make sure the temperature of the water stays between 60-70 °F (15.56-21.11 °C). This temperature is optimal for most ferns.

9. You Need To Provide It With Fertilizer

Ferns will significantly benefit from being provided with fertilizer. While these plants aren’t heavy feeders, you need to feed them minerals and nutrients every month.

Feeding your fern fertilizer will result in healthier roots and healthy overall growth. It is vital to provide this plant with hydroculture fertilizer during its best growing periods: summer and winter.

Ensure that your fertilizer is water soluble and only add small amounts.

The Verdict

Ferns are one of the most prevalent plants in the world. They’ve been around for millions of centuries and will be around for many more.

These epiphytic plants can survive and thrive in many conditions, and growing them underwater is a great way to keep them hydrated. However, remember to consider the above points to give them the best chance of survival.

Alexander Picot

Alexander Picot is the founder of and its lead content writer. He created the website in 2022 as a resource for horticulture lovers and beginners alike, compiling all the gardening tips he discovered over the years. Alex has a passion for caring for plants, turning backyards into feel-good places, and sharing his knowledge with the rest of the world.

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