A Snappy Guide to the Crocodile Fern (Microsorum musifolium)

True to its name, the Crocodile Fern looks the real deal.

Boasting broad strap-like foliage and characteristic scaly leaves (known as clathrate scales) made from deep emerald venation – it’s a stunning tropical plant.

And the colors only deepen as the plant matures.

This Malaysia-native epiphytic fern will truly bring a tropical aesthetic to your home. Or, it could be a fantastic addition to larger terrarium tanks with lots of space, humidity, and moisture.

When properly maintained, it’s a lovely low-maintenance fern.

So, let’s jump into how to care for it!

Where to Buy the Crocodile Fern

See the links below to purchase from reputable terrarium plant shops and marketplaces (may include affiliate links). 

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Crocodile Fern Care & Growth

Plant TypeFern, large
LightingBright indirect light
Temperature65-75ºF (18-24ºC)
WateringRegular, even moisture
HumidityHigh humidity (60-90%)
Growth10-20 inches

Lighting

Thanks to its native life in the canopy, the Crocodile Fern can actually handle a fair range of lighting conditions. It’s only really at the extreme ends of the scale you’d have an issue.

Haha, scale… Get it? 😂🐊

That said, they tend to stay a more vibrant green color with moderate to bright, indirect light, whereas too little light will cause them to fade into a more silvery tone.

crocodile fern with lightmeter
To avoid this, make sure it’s regularly getting a minimum of 200 footcandles.

With too much light the fronds may burn.

But these plants grow under the Southeast Asian sun with only partial shade, so they’ll be able to handle their fair share of sun without scorching.

crocodile fern near window
I’ve been keeping my large Crocodile Fern about a foot away from a South-facing windowsill, where it gets plenty of yummy, bright, indirect light.

Watering Requirements

The Crocodile Fern is one of those tropical fern species that loves moisture but doesn’t like its roots in soggy substrate.

So, the challenge lies in maintaining consistent even moisture.

It’s notably not very drought tolerant at all, so it’s probably better to have it slightly too wet rather than too dry (as long as you have adequate drainage).

For this reason, I found that keeping it in a terracotta pot wasn’t a great idea. It may be gorgeous, but it’s also far too porous and wicks moisture away from the soil.

Stick to a glazed or plastic pot instead.

watering crocodile fern
I regularly test the soil moisture with my finger and give my thirsty Crocodile Fern a drink whenever the very top has dried out a little.

Keeping the humidity high and selecting an appropriate substrate mix can make this process a lot easier.

Best Soil/Substrate

As you know, in the wild, Microsorum musifolium is actually an epiphyte, making its roots fairly shallow.

This makes getting the right substrate even more crucial than with other tropical plants.

A substrate with excellent water retention will help this fern maintain its moisture, but good drainage is important, too, as they’re not used to sitting in a wet substrate.

Something similar to the classic ABG mix would be ideal.

Base ingredients like coco coir and sphagnum moss are ideal because they’re spongey and moisture-retentive. Additives like orchid bark and lava rock can help keep the mixture chunky for drainage.

In my Crocodile Fern terrarium build, I used a bioactive substrate.

planting crocodile fern in soil
My substrate consisted of coco coir, sphagnum moss, earthworm castings, orchid bark, charcoal, and leaf litter (complete with bioactive custodians, too – spot the Dairy Cow isopod on the cork bark!).

Temperature & Humidity

When it comes to Microsorum musifolium, you’re going to want to keep the temperature and humidity as consistently high as possible.

It doesn’t need super high temperatures, but it is sensitive to cold drafts or sudden swings, so keep it away from any vents or drafts.

You can boost humidity in the home by grouping plants or keeping open watering cans around the room for the water to evaporate into the air.

crocodile fern with temperature and humidity guage
60°F and 50% humidity are as low as I’d recommend going for this plant.

Naturally, a tropical closed terrarium environment is a really great way to keep this plant happy.

crocodile fern in tropical terrarium build
My Microsorum musifolium looks amazing in this terrarium build.

Growth Pattern

Being an epiphyte in the wild, these monsters are most often found growing in the crooks of large trees.

tropical epiphytic fern in tree
Here’s a great example I saw when on a trip to Malaysia – while not a Crocodile Fern per se, it could easily be a member of the Microsorum family.

They can get huge too, reportedly up to 6 feet in the wild (!), but indoors – and especially in terrariums – they’re not likely to grow anywhere near that.

Crocodile Fern
I’ve found my Crocodile Ferns to be fairly slow growers, so you don’t need to worry about it getting too big too fast.

That said, in a terrarium, it definitely works best in larger and tank-style containers where it has plenty of room to flourish.

How to Propagate the Crocodile Fern

As with many ferns, division is the easiest way to propagate the Crocodile Fern, and this species does so readily.

Gently tease apart the root system till you have not one but two lovely plants.

dividing crocodile fern
I found my Crocodile Fern divided into two fairly easily, but if you need a little extra assistance, you can use secateurs or scissors to cut through any tough rhizome.

Don’t worry if a frond or two is lost in the process – it should recover just fine.

Then, just plant these new babies up, either in a pot or a new terrarium build.

Varieties & Similar Plants

Microsorum is a big and bold genus, both in number (with around 50 fern family members) and in character; there’s a huge amount of variation, but they tend to share large and broad foliage.

For paludarium and aquarium lovers, there are even some aquatic Microsorum species to experiment with, such as the dainty Java Fern – Microsorum pteropus.

Other larger, impressive species include the Kangaroo Paw Fern – Microsorum diversifolium, keeping with the animal theme, or the Wart Fern – Microsorum scolopendria, presumably named for its gnarly spores.

kangaroo fern close up
My Kangaroo Fern is gorgeous.