Perfect Maidenhair Fern Guide

17 Jul 2022

Maidenhair ferns, or as they are scientifically known… plants of the Adiantum genus, are very popular houseplants. They are actually one of the best-known types of fern houseplants to exist.

They can also be a bit difficult to maintain indoors because they need certain conditions in order to thrive, but as long as you have a good understanding of what those conditions are you can expect to have a healthy and beautiful Adiantum in no time.

This guide is meant to teach you everything you need to know about this genus so that your gardening endeavors with it will be successful.

Main Characteristics

In order to understand how to take care of a certain plant genus though, you must know a lot about that genus first. Every plant’s characteristics has a lot to do with how you take care of it.

So let’s get into the main characteristics of the Adiantum genus.


There are about 250 different varieties within the Adiantum genus, so it’s impossible to discuss them all but we’ll list a few of the more commonly discussed ones in this section.

  • Adiantum Raddianum: This is the classic variety of Maidenhair fern that most people think of when they hear the name. It features delicate and drooping emerald leaves.
  • Adiantum Pedatum aleuticum: This variety is much larger than the more classic version, and stands out because of its black stem.
  • Adiantum Pedatum: This variety also has the black stalks and is similar to the pedatum aleuticum but it’s much smaller.
  • Adiantum Capillus-venerus: Much like the two previous varieties, this one has black stems. But its unique feature are its fan-shaped leaflets.

How Big Does It Get?

Many different variables go into predicting how large a houseplant of a certain genus will get, such as environmental conditions, care, and the exact variation in question.

For instance, the Mandevilla could turn out anywhere from 3 to 10 feet (0.9 to 3 meters) tall purely depending on how much sun it receives.

Variables aside though, most fully-grown Maidenhair ferns will grow to be between 1 to 3 feet (0.3 to 0.9 meters) tall and between 1 to 2 feet (0.3 to 0.6 meters) wide.

How Fast Does It Grow?

The Adiantum genus is known for growing quite slowly, as even a well cared for Maidenhair fern will take about 3 years to reach its full size. But this also means that you probably won’t need to repot it often, which can be seen as a positive for many people.

This is a perennial plant, and perennials typically grow from 0.8 to 1 inches (2 to 2.5 centimeters) per week. But seeing as this genus grows slowly, you should probably expect growth closer to the lower end of that spectrum if not slightly below it.

How Long Does It Live?

The minimum amount of time that healthy houseplants will live is usually from about 3 to 5 years. But this is the minimum for most plants, and for a genus like the Adiantum you should expect a maximum lifespan of up 20 to 30 years.

There have even been cases of ferns lasting over 100 years! Their lifespans can be greatly increased through the process of propagation since it will give them a new lease on life, so to speak.


Thinking about whether or not a houseplant is toxic is one of the most important things to consider, especially if you have young kids or pets that are in danger of ingesting parts of the said plant. So here are the answers you’ll need –

Is It Toxic to Cats and Dogs?

Plants of the Adiantum genus are completely non-toxic to pets, cats and dogs alike. Of course, ingesting plants always poses certain risks for pets because of choking hazards. But as far as toxicity goes, these plants won’t harm your pets.

So don’t worry if you’ve found that your dog or cat has ingested parts of your fern, they’ll be completely fine.

Is It Poisonous to Humans?

Maidenhair ferns are not toxic to humans, unless large amounts are ingested. And even if large amounts are consumed then you should only have to worry about an upset stomach for a couple of hours and nothing more serious than that.

This means that this genus is one of the few that is safe to have placed anywhere around your house, even if you have small kids running around.

Maidenhair Fern Care

This is a fairly difficult genus to take care of, but this doesn’t mean that beginners can’t still have a thriving Adiantum! It simply means that you need to take special care with this houseplant, and take some extra time researching exactly to care for it.

This care guide section will take you through all the steps that you’ll need to know.

How Often to Water It

Maidenhair ferns are one species that needs a lot of water in order to thrive, much like the Coleus. So although you still need to be mindful of root rot, the soil should always be kept moist.

In order to keep the soil at a constantly moist level, you’ll need to water your Adiantum about once a day or every other day depending on how the soil feels to you.

And remember to keep an eye out for yellowing leaves, and other signs of root rot. If your plant develops root rot then you’ll need to address it right away.


Because of how much water this genus needs, making sure it’s properly drained is extra important to avoid dangerous illnesses like root rot. Your Maidenhair should never have its roots sitting in water.

So you need to make sure to choose a pot with drainage holes. Some people even put their Adiantum in a plastic pot with drainage holes, and then put that pot into a more aesthetically pleasing one.

Using this method, you’ll be able to water your plant over the sink and let the water pour out of the drainage holes before you place your plant (plastic pot and all) back in its decorative pot.

How to Prune It

This is actually a step that you could skip if you don’t have the time to do it, because ferns don’t typically require much pruning. But if you wish to, then you can feel free to trim and prune your Adiantum just to keep it looking fresh.

  1. Start by shaping your plant in any way you wish. If you’d prefer less leaves in the front then prune off the front bits, etc…
  2. Then you should trim off any damaged or discolored leaves that you notice.
  3. Many people like to keep the bottom of their ferns trimmed, so if you’re inclined then you could trim near the base of the plant and leave the top full.

Much of trimming a Maidenhair has to do with personal preference since it’s not always a necessary step.

Environment Conditions

But proper care is nothing without the proper environment, so you should make sure to know all about the ideal environmental conditions of your new houseplant. All the information you need to know about it will be listed here!

Light Requirements

The optimal lighting for this genus is a place where it can receive indirect sun exposure. Since the leaves of the Adiantum are so delicate, full-on sun exposure will quickly result in burnt leaves.

The best spot would be one where the morning or afternoon light shines in but the plant still has access to plenty of shade to keep it cool. Many people choose to keep their Maidenhairs around a northern-facing window.

Best Soil

There are a couple of key factors to consider when choosing the soil for your Maidenhair fern…

  • It needs to drain well. The best way to achieve this is by adding some moss, compost, or other organic matter to the soil. This will help it retain moisture.
  • Furthermore, Maidenhair ferns do better in soil that is slightly alkaline.


This another step that you can skip if you’d like, the Adiantum genus is much like the Aloe Vera plant in the sense that it doesn’t need fertilizer in order to thrive.

But if you would like to give your Maidenhair some fertilizer then it won’t do it any harm, and it can provide it with some extra nutrients. Just make sure to dilute the fertilizer with some water in order to avoid harming the plant with too many nutrients at once.

Also, avoid fertilizers with too much nitrogen as it could cause your Adiantum’s leaves to brown. But as long as you keep those things in mind then you can fertilize your Maidenhair about once a month during the spring and summer.

Pot Size and Type

A clay or plastic pot would be suitable for this genus. The only real thing you have to keep in mind is that there must be drainage holes.

Additionally, Maidenhairs do the best in shallow pots since their roots don’t reach very far.

You also don’t have to worry too much about the roots getting bound up, so as long as there’s about 1 inch (2.5 centimeters) of space between the roots and the pot in order to allow for growth, everything should be fine.

Temperature Tolerance

This genus is quite sensitive to temperature so finding the right one is important. The ideal temperature for this houseplant would be about 70 degrees Fahrenheit (21 degrees Celsius) or even slightly warmer.

But be sure not to let the temperature drop below 60 degrees Fahrenheit (16 degrees Celsius), as this could cause serious damage to the plant.

Humidity Level

For a Maidenhair fern to reach its full potential and be its healthiest, it needs to be in a humidity level of about 60% so that its leaves can stay moist. This can be hard to achieve indoors though, so there are some things you can do in order keep the leaves moist even in dryer air.

Placing your fern in the bathroom near a shower or bath, next to another plant, or next to a humidifier are all ways that you can increase the humidity to the correct level.

Or you could spray a mist of warm water over the plant’s leaves every day to give them some much-needed moisture that they’re missing the air.

Outside or Inside?

If you’re planning on keeping your Maidenhair inside then you can have more control over it’s environment which is always a positive thing.

But if you’re planning on keeping it outdoors then it can live in climate zones of 3-11 but zones 8-10 are optimal.

Does It Flower?

Ferns do not produce blooms and the Maidenhair fern is no different. If you’re looking for a houseplant that produces stunning blooms then you might want to take a look at the Cyclamen!

How to Grow It


About once every year to two years, you’ll need to propagate your Maidenhair fern if you want it to stay healthy and manageable. The process to do this is really simple, here are the steps –

  1. Pull the plant out of its current pot.
  2. Using a sharp knife, divide the roots of the plant into manageable sections. Two to three fronds should be enough for each section.
  3. Ready whatever number of pots that you’ll need, and fill them with soil.
  4. Place each section of your newly divided fern into its own pot.
  5. Water them appropriately.

How to Plant the Spores

The first step of taking care of your new fern is, of course, to plant it. But ferns don’t grow from seeds like other plants, instead ferns grow from spores. Don’t worry though, planting spores isn’t that much different than planting seeds and we’ll teach you the proper steps.

  1. Find an appropriate container. It must have a tight covering of some sort, and you need to clean it either with a bleach solution or by running it through the dishwasher.
  2. Choose your growing mix and sterilize it by wetting the mix down to a mud-like consistency, and then warming it in the microwave at level 10 for about an hour. You could also bake it in the oven at 250-300 Fahrenheit (121-149 Celsius) for about 2 hours.
  3. Place the sterilized growing mix into the clean containers.
  4. Next you should sow the fern spores by sprinkling them on top of the growing mix, but make sure to do it in a draft free environment to avoid contaminants getting into the containers.
  5. Take care of the spores until they reach a maturity level at which they can be planted in a pot. Keep them watered, give them sun, monitor them for health issues, and wait for the magic to happen.

Why May It Be Dying?

Especially with such a sensitive plant, it pays off to know about things that could go wrong with it and what to do if it gets sick. So in this section we’re going to cover some of the most common illnesses that this genus faces.

Root Rot

Just like so many other plants, such as the English Ivy, this species can contract root rot. Signs include a lack of growth, wilting, and most commonly yellowing leaves.

If your fern contracts root rot then you should clip off any brown and mushy root sections, repot it, and make sure not to overwater it again.

Leaf Spot Disease

This infection can spread quickly and is characterized by brown spots appearing on a plant’s leaves. These spots might grow larger or harden, they may also start to eat away at a leaf and leave holes behind.

You can’t sure this disease, but by clipping off the affected leaves you can avoid it spreading to the rest and therefore save your plant’s life.

Southern Blight

This issue will cause low-lying leaves to die and fall off, and may also cause root rot.

You can treat this issue by clipping off severely affected leaves, discarding any leaves that have been affected and fallen off, and spraying the plant with some hydrogen peroxide until the rest of the disease fades away.

If it’s caused root rot then you can address that with the steps we’ve already mentioned earlier.

Final Remarks

The Adiantum’s reputation for being hard to deal with shouldn’t keep you from trying to grow one. As long as you know what you’re dealing with and take special care with it, you’ll have a healthy and beautiful plant in your home.

And not only will your efforts be rewarded aesthetically, but it’s also worth it to have a non-toxic houseplant option if you have cats, dogs, or kids around. So definitely don’t count out the Maidenhair fern!

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