Nephrolepis (Boston Fern): The Perfect Terrarium Fern
I have been using Nephrolepis ferns in my terrariums for years, so it should come as no surprise that I absolutely love them. They look great, they’re easy to care for and, furthermore, they’re pretty gosh-darn affordable!
Famous for their graceful, arching fronds and vibrant green colour, Boston ferns not only add a splash of nature’s charm to any space but also thrive beautifully within the humid, enclosed environments of terrariums.
This is an exclusive and conclusive guide to the ever-popular ferns belonging to the genus Nephrolepis.
Throughout this guide, I will unravel the secrets of the Boston fern, from its character and growth habits to its basic and advanced care requirements.
I will also draw on my years of experience as a terrarium-maker-in-chief at ome to deliver the best tips and tricks to make the most from your Nephrolepis in terrarium designs.
Additionally, I’ll provide a comprehensive troubleshooting companion guide alongside an extensive list of FAQs to ensure nothing is missed.
Anyway, enough with the preamble, let’s begin!
Quick Guide
- Understanding Nephrolepis
- Exploring the Nephrolepis Family Characteristics
- The Benefits of having Nephrolepis in the home
- Nephrolepis’ Basic Care Requirements
- Nephrolepis’ Advanced Care Requirements
- Nephrolepis safety/toxicity for pets
- Using Nephrolepis in a Terrarium
- Why Choose Nephrolepis For Your Terrarium
- Plants to pair with the Nephrolepis
- Nephrolepis Terrarium Projects to Try
- More on Nephrolepis
1 | Understanding Nephrolepis
1.1 | Exploring the Nephrolepis Family Characteristics
In the lush underbrush of the world’s tropical regions, a family of ferns has flourished, capturing the hearts of plant lovers the world over: the Nephrolepis.
Nephrolepis exaltata, commonly known as the Boston fern, originally hails from humid forests and swampy regions in tropical climates.
Its native range spans from South America to Africa and parts of the West Indies, it therefore thrives best in warm, moist climates.
This genus, home to around 30 species, boasts some of the most beloved ferns for indoor gardening and terrarium cultivation.
Nephrolpeis exaltata
At the forefront is Nephrolepis exaltata, the Boston fern, with its feathery, cascading fronds that have brought a touch of verdant wilderness into the homes of millions (or, maybe just thousands…I don’t know. A lot of homes, anyway).
Boston ferns boast a rich green hue that instantly breathes life into any terrarium. Their shapely and arching fronds can grow up to and between 50 and 250 centimetres long!
Each frond unfurls from a central rhizome that lies dormant before springing into a fan of leaflets scientifically termed 'pinnae'.
These delicate leaflets cluster tightly along the fronds, creating a feathery appearance that's both classic and graceful.
But it's not just the Boston fern that merits perusal.
Within the Nephrolepis genus, diversity abounds:
For example, there is the 'Fluffy Ruffles' with its exuberant and intricate leaves and the 'Dallas Fern', which is more compact and well-suited for smaller terrariums—these are just some of the siblings’ worth mentioning.
Each species can uniquely elevate your home or a terrarium.
Let’s explore how.
1.2 | The Benefits of having Nephrolepis in the home
Honestly, having any plant in the home has innate benefits. [CITATION]* Studies have repeatedly demonstrated the beneficial and therapeutic mental effects of having thriving plant life in the home.
Perhaps there are some exceptions – you don’t exactly want fungi sprouting from your bathroom tiles or deadly hemlock in your herb garden.
But you’ll find no such exceptions here; the Nephrolepis ferns are a certified delight.
Though they remain contained inside terrariums, Boston ferns can get pretty big in the home!
Let’s break down some of the household benefits of being a proud Boston fern owner:
- Air Purification: Nephrolepis exaltata is known for removing pollutants such as formaldehyde, xylene, and toluene from the air, making it an excellent choice for improving indoor air quality.
- Humidity Regulation: Boston ferns help maintain and increase indoor humidity levels by releasing moisture into the air through transpiration, which is beneficial for respiratory health and well-being.
- Aesthetic Appeal: With its lush, green fronds and graceful growth, the Boston fern adds a touch of natural beauty to any space, enhancing the visual appeal of home and office environments.
- Low Maintenance: Nephrolepis plants are relatively easy to care for, requiring only consistent moisture and indirect light, making them suitable for gardeners of all skill levels.
- Therapeutic Effects: The presence of vibrant green plants like Nephrolepis exaltata can reduce stress and promote a sense of well-being, making them a great addition to both personal and professional spaces.
- Versatility in Placement: Boston ferns are perfect for bathrooms, kitchens, and other moist areas of a home or office due to their adaptability to varying light conditions and ability to thrive in high humidity.
- Natural Cooling: These ferns can help slightly reduce the ambient temperature through transpiration, making indoor spaces feel cooler and more comfortable during warmer months.
1.3 | Nephrolepis’ Basic Care Requirements
Let’s break down the basic care required for keeping your Nephrolepis plants healthy.
In my experience, ferns lie on the fussier side of the houseplant care spectrum.
Terrariums are a great shortcut to achieving consistency in Nephrolepis care as the environment is tightly regulated.
However, shoving stuff into terrariums isn’t my answer to everything… I swear.
If you can manage these simple steps, your Nephrolepis will thrive in your home.
Light
Nephrolepis exaltata thrives in bright, indirect light.
Direct sunlight can scorch its fronds, while too little light may cause it to lose its lush green colour and become sparse.
A north-facing window or a spot that receives filtered light through sheer curtains is ideal.
Temperature
Boston ferns prefer moderate temperatures and do well in typical indoor environments ranging from 60-75°F (15-24°C).
They should be protected from drafts and sudden temperature changes, which can stress the plant.
Avoid placing them near heating vents or air conditioning units to prevent drying out.
Additionally, keep your ferns away from the windowsill. Even without direct sunlight, a windowsill can be a problematic position – due to temperature fluctuation.
Humidity
High humidity levels are crucial for keeping Nephrolepis exaltata healthy, mimicking its natural rainforest habitat. Ideal humidity levels are between 50% and 80%.
In dry environments, increasing humidity can be achieved by misting the ferns regularly, placing a humidifier nearby, or using a pebble tray filled with water beneath the plant container.
Again, a bathroom will naturally have higher levels of humidity and is thus a strong candidate for positioning (other conditions permitting).
Watering
Boston ferns need consistent and evenly moist soil; it’s essential.
Water the plant when the top inch of soil feels dry to the touch, ensuring the soil is damp but not soggy.
Overwatering or allowing the roots to sit in water can lead to root rot, while under-watering will cause the fronds to dry out and become crispy.
During winter, watering should be reduced slightly as the plant’s growth slows down.
Soil
Nephrolepis thrive in loose, well-draining soil that retains moisture without becoming waterlogged.
A great and sustainable alternative blend to peat-based mixes is the combination of coconut coir, compost and an aerator.
Coconut coir, similar to peat, provides excellent moisture retention and aeration properties. It is a renewable resource made from the fibrous husks of coconut shells.
Mixing in some compost will enrich the soil with nutrients and improve its structure. Worm castings are a great choice.
This blend should also include an aerator such as sand, orchid bark, perlite, or vermiculite to enhance drainage and prevent root rot. These materials will also aerate the soil, allowing oxygen to reach the roots over time.
I typically aim for a slightly acidic pH, between 5.0 and 5.5, to best support fern health.
I recommend regularly checking the soil condition and refreshing it annually to ensure it remains healthy and supportive of robust fern growth.
1.4 | Nephrolepis’ Advanced Care Requirements
The above care requirements are all that you essentially need to take good care of your Nephrolepis ferns.
But there’s nothing wrong with having a few more leaves on your stem!
Let’s look at some of the more advanced care provisions for the Nephrolepis.
Any dead, rotting or leggy stems can be trimmed at the base
Pruning
Pruning is essential for maintaining the shape and health of almost any houseplant.
In my practice, I prune Nephrolepis in the spring to rejuvenate the fern and encourage fresh growth.
Use sharp scissors to snip off any brown or dead fronds at the base. Also, thinning the centre of your fern can prevent fungal issues by improving air circulation.
Repotting
Nephrolepis exaltata benefits from repotting every couple of years to prevent root crowding and replenish nutrients.
I recommend a pot only slightly larger than the current one, as too much space can lead to excess moisture retention.
When repotting, carefully untangle the roots and trim any dead ones before transferring the plant into the new pot with a fresh soil mix.
Propagation
I rely on division for propagation. In the spring, gently remove the plant from its pot and divide it into smaller sections, each with a portion of the root system intact.
Use your hands to pinch the base of the plant and very gently eek the plant apart, you should see a natural separation point – whereby after splitting you have two or more plants with root bases.
Plant each section in a pot with a suitable potting mix.
Propagation provides a perfect opportunity to share your ferns with friends! If you don’t have any friends, try sharing them with your enemies instead. Keep ‘em close.
Ensure to thoroughly water each division.
Nutrition
Feeding your Boston fern provides the extra nutrition needed for lush growth.
During the growing season, I use a balanced, water-soluble fertilizer diluted to half-strength monthly. In the winter, when growth slows, I reduce feeding to every other month.
Always water the soil before fertilising to avoid root burn.
Remember, the key to advanced care is observing your plant’s response and adjusting your methods as needed.
1.5 | Nephrolepis safety/toxicity for pets
I’ve got good news! Nephrolepis is one of the safest household plants you can keep.
For Pets: Boston ferns are non-toxic to cats and dogs.
While it's always best to prevent pets from chewing on plants due to the potential for gastrointestinal upset, you can rest assured that the Boston fern is not poisonous to them.
For Other Animals: Like household pets, there is no evidence to suggest that Nephrolepis exaltata poses any toxicity risk to other animals.
However, as with all plants, it's wise to monitor and prevent access, especially with animals that might be more inclined to eat plants, as individual reactions can vary.
For People: This fern is also safe for humans.
It does not pose any risk of toxicity when touched or ingested in small amounts.
Of course, it's not intended for consumption, so I wouldn’t recommend scoffing any. But why would you?
It's always a good practice to wash your hands after handling plants, as they can carry soil or plant residue that might irritate sensitive skin or cause an allergic reaction in some individuals.
But overall, when it comes to safety and toxicity, the Boston fern is one of the better plants for a space shared with pets and family.
2 | Using Nephrolepis in a Terrarium
As mentioned, I often use Nephrolepis ferns in my terrariums. I’ve probably used hundreds of them.
And that’s no coincidence…
I’ll tell you why:
2.1 | Why choose Nephrolepis for your terrarium?
Visual Appeal
In my terrarium designs, I've found that the feathery, vibrant fronds of Nephrolepis ferns add a dramatic visual impact.
They introduce a lush, mini forest feel that creates a ‘busyness’.
Often, terrariums can feel sparse and leggy, but these ferns do a wonderful job of making the environment feel more natural.
Suitability in Terrariums
Nephrolepis are one of my terrarium go-tos simply because they thrive in the consistent, humid conditions these glass gardens provide - which mirror their native tropical habitats.
Terrariums often make for a great habitat alternative to houseplants kept in the home, especially for fussy ferns.
Compact Growth
Nephrolepis is also fantastic for its dense yet contained growth within a terrarium.
It fills a space beautifully, contributing to the landscape without becoming overbearing.
Over time, you may find your Nephrolepis, as a rhizomatous plant, spreads around your container gradually over time, making it ideal for creating a dense green backdrop in terrarium landscapes.
Boston ferns tend to clump, rather than getting leggy - which keeps your designs looking trim.
Low-Root Impact
Another practical reason I often include Nephrolepis in terrariums is its non-invasive root system, which makes it a peaceful neighbour to other terrarium plants.
Other choices are more likely to dominate your terrarium more quickly over time – which isn’t necessarily bad, but the Nephrolepis gives a little more stability.
Affordability
When building terrariums, especially if frequently; cost is a factor.
As a common plant – the Nephrolepis is an economical choice, allowing for a lush look without stretching the budget.
Readily Accessible
Time is of the essence in my work, so the widespread availability of Nephrolepis is a huge plus.
It’s a relief to know I can easily source these ferns for my projects. Due to their popularity, they are readily grown in nurseries worldwide.
2.2 | Plants to pair with the Nephrolepis
Now, one thing you won’t find in other Nephrolepis articles is a pairing guide (until someone comes over here and nabs my idea, that is).
The 13 top terrarium plants for beginners.
When it comes to making a terrarium, I find beauty just as important as function. So, here are my five favourite plants to pair the Nephrolepis ferns with and why:
Other ferns
Ok so this probably looks like quite a lazy entry but – there’s nothing like a bit of fern-on-fern action, trust me.
Whether the differences in shades of colour or leaf types are subtle or striking – ferns go together.
You usually try to evoke a certain type of environment with a terrarium. You’ll usually find ferns out in the wild among other ferns, mosses and rich green plants.
They complement each other perfectly, trust me!
Oh, you want specifics? Alright, my top pick would be Polystichum tsus-simense or the ‘Korean rock fern’.
Muehlenbeckia
Muehlenbeckia is commonly used in both outdoor and indoor gardening.
It has similar care requirements to the Nephrolepis genus – but visually much different.
The long, wild vines are dotted with circular, coin-like leaves. These long stems can be traced around the terrarium providing a nice juxtaposition to the enclosed/contained look of the Nephrolepis fern.
Asparagus setaceus
This plant is another terrarium staple, known commonly as ‘Asparagus fern’ (but not technically a fern).
I love this plant just as much as I do the Nephrolepis, possibly more, namely because of the controlled verticality and looming fronds that define it.
These lush green towering stems look almost like a miniature rainforest canopy – and thus are right at home soaring over some bottom-dwelling ferns.
Ficus ginseng macrocarpa
The Ficus ginseng, commonly referred to as a ‘bonsai’ – is one of my favourite centrepiece plants.
The commanding root ball will dominate medium-sized terrariums, and I’ll usually ‘dot’ smaller, bushier plants around it – cascading out from a central position.
Nephrolepis is therefore a perfect partner.
Selaginella apoda
The Selaginella apoda is similar to the Nephrolepis in that it is stout and luscious green.
However, the subtle differences in colour and shape make for a more natural look inside a carpeting terrarium or section of a terrarium.
This one does tend to spread, though.
2.3 | Nephrolepis Terrarium Projects to Try
Let’s give you a practical use for your Nephrolepis.
It’s true; there are loads of ways you can use it inside a terrarium to create wonderful looks.
For example, I often like first to divide the plant and place one up top near the rear of my build, and then another on the opposite side of the foreground.
This creates a natural look, where the appearance of your terrarium ‘rhymes’ with itself.
But, for something more challenging – why not incorporate your Nephrolepis fern into a vertical terrarium?
On your vertical wall, use a hardscape element such as cork bark to create a base, on top of which you can gather more substrate.
Into this substrate, form a hole and place inside your Boston fern.
Boom! A vertical fern garden. Or part of one, anyway.
Give it a go, and let me know how you got on in the comments or if you have any ideas of your own.
3 | More on Nephrolepis
3.1 | Troubleshooting and FAQs
Alright, I will do my best to answer as many common questions as possible I hear about using and how to care for Nephrolepis ferns.
If you think I’ve missed something, drop a comment below!
1. What type of light is best for Nephrolepis ferns?
Nephrolepis ferns thrive in bright, indirect light. Avoid direct sunlight, which can scorch the fronds.
2. What is the ideal temperature for Nephrolepis ferns?
They prefer temperatures between 60-75°F (15-24°C). Keep them away from drafts and sudden temperature changes.
3. How often should I water my Nephrolepis fern?
Water when the top inch of soil feels dry. Ensure the soil is moist but not waterlogged.
4. What type of soil is best for Nephrolepis ferns?
Use a well-draining, moisture-retentive, and slightly acidic soil mix. A blend of coconut coir, compost, perlite, sand or vermiculite is recommended.
5. How do I maintain high humidity for my Nephrolepis fern?
Mist the fern regularly, use a humidifier, or place a pebble tray with water beneath the plant container.
6. Can Nephrolepis ferns be grown in terrariums?
Yes, their humidity requirements and shade tolerance make them ideal for terrarium environments.
7. How do I fertilise my Nephrolepis fern?
Feed with a balanced, water-soluble fertiliser diluted to half strength every month during the growing season. Avoid over-fertilizing, especially in winter.
8. What are some common problems with Nephrolepis ferns?
Common issues include brown and crispy fronds (usually from dry air or under-watering), pest infestations, and root rot from overwatering.
9. How can I propagate Nephrolepis ferns?
Propagate by division. Carefully separate a healthy clump with roots and replant in suitable soil.
10. Are Nephrolepis ferns safe for pets?
Yes, they are non-toxic to cats and dogs, making them a safe choice for pet owners.
11. Can Nephrolepis ferns clean the air?
Yes, they are known to remove common indoor air pollutants, enhancing air quality.
12. How often should I repot my Nephrolepis fern?
Repot every 2-3 years or when the plant outgrows its pot, typically in spring.
13. Do Nephrolepis ferns need pruning?
Yes, prune dead or yellowing fronds to encourage healthy growth and maintain a tidy appearance.
14. What should I do if the leaves of my Nephrolepis fern are turning yellow?
Yellow leaves can be caused by overwatering, low humidity, or a nutrient deficiency. Adjust care accordingly, and ensure the plant is not sitting in water.
15. How do I handle pest infestations on my Nephrolepis fern?
Treat infestations like spider mites or scale with insecticidal soap or neem oil and isolate the plant to prevent spread to other houseplants.
16. How much humidity do Nephrolepis ferns require?
Nephrolepis ferns thrive in high-humidity environments, ideally between 50% and 80%. Regular misting or a room humidifier can help meet their humidity needs in dryer conditions.
17. What is the best way to increase the humidity for my Nephrolepis fern?
Besides misting and humidifiers, placing the fern's pot on a tray filled with water and pebbles (ensuring the pot is not sitting directly in the water) can help increase surrounding humidity.
But, the best thing you can do is to ensure the soil is kept moist (but not waterlogged).
18. Can I grow Nephrolepis ferns outside?
Nephrolepis ferns can be grown outdoors in regions with mild, humid climates. They should be placed in a shady area and monitored closely to ensure the soil remains moist.
19. How can I tell if I am overwatering my Nephrolepis fern?
Signs of overwatering include soggy soil, wilting, and blackening leaves. If the fronds begin to rot or have a mouldy smell, reduce watering frequency and ensure the pot has adequate drainage.
Also, consider temporarily moving the plant to a dryer room to ensure adequate evaporation.
20. Is it necessary to use a specific type of water for Nephrolepis ferns?
While Nephrolepis ferns are not particularly fussy about water type, using non-chlorinated water, like rainwater or distilled water, can prevent potential leaf burn from chlorine and other chemicals typically found in tap water.
21. Can Nephrolepis ferns tolerate low light conditions?
Nephrolepis ferns can tolerate low light but thrive best in bright, indirect light. In too low light, they may become leggy and lose some of their lush green colour.
22. How do I prevent leaf tip browning in Nephrolepis ferns?
Leaf tip browning is often due to dry air or low humidity. Increasing humidity around the plant through misting, using a humidifier, or placing it in naturally humid rooms like bathrooms can help.
23. What should I do if my Nephrolepis fern becomes too large for its terrarium?
If your fern outgrows its terrarium, you can prune it back to maintain its size or transplant it to a larger container or another area that can accommodate its size, redistributing the trimmed portions if it is healthy.
24. How do I revive a Nephrolepis fern that seems to be dying?
First, check for any signs of over or under-watering and adjust accordingly. Ensure the fern is inappropriate lighting and the humidity is sufficient. Remove dead fronds and consider repotting in fresh soil to boost the fern's nutrients.
3.2 | Where to buy Nephrolepis Ferns
If you're in the UK, you're in luck! We have Boston ferns for sale right here.
Otherwise, browse Boston ferns available in your area.
4 | Conclusion
So, there you have it: a comprehensive guide to the Nephrolepis exaltata/Boston Fern.
Experimenting with and learning about new plants is one of the joys of my career in the terrarium landscape (pun intended), and these fluffy delights are undoubtedly a highlight.
Hopefully, I’ve covered just about anything and everything you could possibly want to know, but the comment section below is open to any and all questions, comments, and critiques you might have.
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