Plant Sheet: Boston Fern (Nephrolepsis exaltata)

* Image sources: All images used in this post are from the author

The Boston Fern is a standard in a lot of households around the world. Its love for humidity and hot temperatures doesn’t make it the easiest houseplant to look after but its stunning looks surely make up for it.

Short Sum-Up: Nephrolepsis exaltata (Boston Fern), thrives naturally in shaded, humid, and warm swamps across the Americas. As a highly sensitive houseplant, it tolerates low light conditions but exhibits optimal growth in bright indirect light. Watering should maintain soil moisture without inducing waterlogging.

Get some knowledge about the origins of the Boston Fern as well as some extra care tips to keep this sensitive housemate happy!

Origin and Natural Habitat of the Boston Fern

Nephrolepsis exaltata, commonly called Boston Fern, has its natural habitat in shady, humid, and hot regions mainly in the Americas. It is native to northern South America such as Guatemala, to Central America as well as to Florida and Polynesia. The Boston Fern grows in swamps or on floodplains as a terrestrial species but also as an epiphyte on trees and trunks.

The species is also called Sword Fern because its fronds arch straight upward. In nature, this plant has been witnessed to grow 1-3 feet (3-9 m) tall. It has dark to bright green leaves with spores on the undersides (it’s a fern, after all).

Interesting fact: how the Boston Fern got its name is not entirely sure, though all stories of its naming refer to some shipment of the plant to Boston, hence its name after the North American city.

Brighten Up Boston Fern’s Day: Light and Water Requirements

As these ferns naturally evolved in the undergrowth of forests, taking advantage of the shade of bigger plants and trees, they are not used to bright direct light. Avoid placing them in direct light or the midday sun. Best for Boston Ferns is low to bright indirect light.

They can do with low light conditions, though they do grow much more and much bushier in bright indirect light. To avoid exposing it to too much direct light, I recommend placing it somewhere with filtered light such as behind blinds, milky glass or light curtains.

Tip: What is considered direct and what is indirect light? Find out in this post linked here what spots count as direct or indirect light in your home!

As for the watering requirements, these plants are used to swamps and hence like moisture. But, beware: Moisture doesn’t mean submerged in water! As most people tend to overwater plants, I don’t want you to think that your Boston Fern has to be given much more water than all other houseplants you have.

Just don’t let the soil of your Boston Fern ever dry out completely, it will react sensitively to it. Rather give it a little bit of water every other day or weekly to make sure the top layer can dry out a bit while the main part of the soil remains moist (again: moist, not soaked!).

A Nephrolepsis’s Guide to Happiness: Care Tips

As you might have already noticed by now, the Boston Fern is quite a demanding houseplant and reacts sensitively to changes in its environment and care routine.

If you find a spot in your home where the Boston Fern thrives, leave it there forever. Don’t change the spot! This fern is a creature of habit, just like humans, and it doesn’t tolerate frequent changes very well.

One thing it certainly is very sensitive to is varying levels of humidity. This is especially an issue in areas where winter means dry indoor air due to heating. If you live in such an area, I recommend using a humidifier in your home throughout winter to keep the humidity levels at a constant level.

Another option would be to place the Boston Fern in your bathroom which is probably the most humid room in any house. However, if this works well for your Boston Fern depends on your bathroom. For though the Boston Fern likes humidity, it dislikes ventilation and temperature changes just as much. In bathrooms, we often open the window after showering which causes both ventilation and temperature drops.

I therefore recommend placing the Boston Fern away from doors, windows, as well as from radiators.

Another tip to avoid causing any shock to this fern is to use water always at room temperature.

Reading recommendation: Looking for plants that suit your bathroom? Learn more about what types of plants suit the humid environment of bathrooms through this link!

How To Propagate Nephrolepsis Exaltata

The Nephrolepis exaltata forms an underground rhizome from which roots grow into the soil and the stems of the fronds grow upward. Naturally, ferns also propagate by spores. As a houseplant, asexual reproduction by multiplying its rhizome is the best way to propagate a fern.

To propagate the Boston Fern, you can divide the rhizome into several plants, each with roots and fronds. Take the mother plant out of its pot and check which group of stems are easiest to separate. It is best to choose newer fronds that have grown at the ‘edges’ of the plant. Entangle the root ball and gently cut through the rhizome with a sharp knife.

Make sure that your plant division has roots, rhizomes, and fronds on it. Repot the new plant into fresh soil (make sure it is well-draining soil) and let it root in its new environment. Ferns are slow growers, it may take 6-8 weeks until you see the first signs of new fronds growing upward from the rhizome. Patience is needed here!

Naturally, ferns propagate mainly through spores on the underside of their leaves as the spores you can see in this image. As a houseplant, it is more common to propagate ferns by cutting a piece of their rhizome. (Image source: author photos)

Boston Fern Superpowers

Not only is the Boston Fern a pet-safe, non-toxic plant, but it also has incredible powers to extract toxins from the air and the soil. It purifies the air from volatile organic compounds (VOCs) such as benzene, ethylene, formaldehyde, toluene, and xylene.

As for its powers to extract and convert toxins present in the soil, there is currently a lot of scientific research going on in a field called phytoremediation. Phytoremediation is ‘the science of using plants to help clean up pollution’ (Desert Sun, Oct 19, 2019). It is the science of using plant’s capacities to transform toxic into non-toxic substances to reduce the pollution humans have created. Many studies are showing how the Boston Fern can take in and transform heavy metals such as arsenic through its roots.

Ferns such as the Boston Fern are specifically valuable in phytoremediation research due to their millennia of evolution, survival, and resilience on planet Earth – ferns are among the first plants growing on Earth more than 300 million years ago!

With their filtering capacities, ferns such as the Boston Fern are ancient natural pollution fighters!

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