Crispy wave fern plants have become really popular lately (and rightly so!) because of their beautiful wavy fronds that add interest and texture to a space and for their bright green color that can liven up a home or office.
In this article, I’ll cover all the nitty gritty details of how to properly care for a crispy wave fern and answer the most common questions that people ask.
This article may contain affiliate links to products I know and love. You can read my full disclosure at the bottom of the page.
PS: Love my pot in the picture above? Me too! You can buy the pot here (there’s also different colors and sizes!)
In case you’re in a hurry, here’s a quick summary of how to take care of a crispy wave fern:
- Light: Moderate, indirect sunlight.
- Soil: I highly recommend this well-draining soil with high peat content. I also explain how you can make your own soil later in this article.
- Water & humidity: Keep the soil evenly moist, but not soggy. Water the soil, not the center of the fern. Humidity should be a minimum of 40 to 50%, but higher is even better. Too dry in your home? This humidifier works great for regulating the humidity in my house.
- Fertilizer: Fertilize once a month during the growing season (April to September) with Dyna-gro 9-3-6 fertilizer diluted to half strength.
- Propagation: Crispy wave ferns are propagated via spores and not root division.
- Toxicity: None. This plant is safe for pets.
Now, let’s take a deeper look into caring for your crispy wave fern so we can keep that baby alive!
1. What is a crispy wave fern?
The crispy wave fern is a cultivar of the Asplenium plant (also commonly called birds nest fern), and it’s scientific + variety name is Asplenium nidus ‘CRISPY WAVE’.
There are other varieties of Asplenium nidus or “Birds nest ferns”, so if you’re specifically looking for a crispy wave fern, make sure the plant you intend to buy is labeled as a crispy wave.
What makes the crispy wave fern unique is it’s stiff and wavy fronds that form an upright, rosette plant habit and the fact that it grows in a more dense, bushy form than other Asplenium ferns.
It’s native environment is tropical, humid jungles under the canopy formed by other trees, which plays a big part in how we have to care for it.
How big do crispy wave ferns get?
Crispy wave ferns are slow growing and will grow to the size of their container, up to a size of about 18 to 24 inches tall and 12 to 18 inches wide (or about 45 to 60 cm tall and 30 to 45 cm wide for all you plant lovers outside the US).
Although, they could grow even larger than this under the perfect conditions (i.e., in a tropical jungle… ok, don’t get any wild ideas over there Tarzan 😆 if you’re anything like me your plant addiction has probably caused your house to start feeling like a tropical jungle!)
2. How much light does a crispy wave fern need?
Crispy wave ferns do best in moderate, indirect sunlight. Do NOT put them in direct sunlight… not even a little bit… they will burn.
I keep my crispy wave fern in a room that gets a good amount of light from the window, but I DO NOT keep it directly in front of the window. I set it back away from the window on a plant stand with some of my other indirect light loving houseplants.
These plants can survive in low light conditions as well, but they may not grow much (and keep in mind they’re slow growers to begin with). The color may also start to fade if it’s in lighting conditions that are too low.
If you want to put your crispy wave fern in a room that gets a lot of direct sunlight, consider putting some shear curtains over the window to filter the light (your fern baby will thank you).
3. How often do you water crispy wave ferns?
How often you water crispy wave fern plants will vary depending on things like the amount of light and humidity and the temperature your plant is exposed to in your home.
Crispy wave ferns like to have evenly moist soil. So, the best way to know if your fern needs water is to feel the soil and stick your finger about an inch or two into the soil. If the soil feels dry, your crispy wave needs a drink.
Make sure your pot has drainage holes and the soil is well draining (which we’ll talk about in the next section) because crispy wave plants do NOT like to sit in soggy soil (and can we blame them? I don’t like walking around in soggy socks either…). Soggy soil (or soggy socks) can cause root rot (or foot rot), which is the quickest way to kill your fern baby.
Also, avoid watering the center of your crispy wave fern, which could also lead to rot and other issues due to stagnant water. Instead, water the soil beneath the fronds all the way around your plant so it gets an even watering.
Watering in the morning is best, so your plant has time to take in the water and excess water can evaporate before night time to avoid mold or fungus.
Using room temperature, filtered water will make your fern even happier, as you will avoid the temperature shock to the roots and any chlorine/fluorine that may be in your tap water.
Do crispy wave ferns like humidity?
YES! Crispy wave ferns, and all ferns for that matter, love and need humidity. Remember, ferns come from humid jungles, so they really need a humid environment to be healthy and look their best.
The minimum humidity you should provide for your crispy wave fern is 40 to 50%; higher is better if you can tolerate it. (We often have to strike a balance between what’s comfortable for us and our plants… similar to the A/C wars we have with our spouse / partner / roommate… yep, guilty.)
If you live in a humid part of the world, this may not be a problem for you (unless you run the A/C or heater a lot, which will dry out your home).
HOWEVER, if you live in an arid, dry area, humidity is definitely something you need to plan for.
The BEST way to improve the humidity in your home and for your plants is to get a humidifier. Here’s the humidifier I like for my plant babies and myself.
There are slightly cheaper humidifiers out there (which I made the mistake of buying at first), but I like that this humidifier actually tells me what the humidity is in my house AND I can set it to maintain the humidity level I choose. The cheaper ones just run until either I turn them off or they run out of water, and then I still don’t even know what the humidity level is in my home.
Also, a humidifier will benefit not only your ferns and other house plants (which are typically tropical humidity loving plants too) but also you and your family according to the Mayo Clinic, who recommends a healthy humidity of 30 to 50% in your home. (Luckily, that’s pretty close to what ferns and other tropical houseplants like too! It’s a win-win… finally.)
If you don’t want to buy a humidifier, your next best option is to put a pebble tray below your plant and fill it with water to just below the top of the pebbles. This will help create a bit of localized humidity for your plant as the water evaporates.
Finally, ensure your fern isn’t near an A/C or heat vent, as the drafts and sudden temperature changes could stress your plant and cause it to not look it’s best.
4. What type of soil is best for crispy wave ferns?
The best soil for crispy wave ferns contains high peat or coconut coir content to hold in moisture but is also well draining so your plant is not sitting in water or super soggy soil (which can lead to root rot…and death 💀 ).
The image above shows the potting mix recipe I use for my crispy wave fern. I mix 2 parts peat moss or coconut coir, 1 part perlite, 1 part fir bark, 1 part horticultural charcoal, and 1 part worm castings to make a nutrient-rich potting mix that holds moisture but is well draining. I’ve provided links to the products I use and highly recommend above.
Or, if you prefer to buy a premixed soil, I really like this soil specially made for ferns.
Another thing to consider is the type of pot you choose for your crispy wave fern. Plastic pots or ceramic pots with drainage holes work best for ferns because they keep moisture in the soil but allow excess water to drain out.
On the other hand, terracotta pots are porous and will pull moisture from the soil, and while that can be good for some houseplants, ferns prefer consistently moist soil.
If you do choose a terracotta pot, you will need to monitor your soil moisture more closely and water more than you would if your fern was in a plastic or ceramic pot.
What I like to do is keep my crispy wave in this plastic grow pot (or something similar like what it comes in from the nursery) and just place the whole thing in a prettier cover pot (this 6 inch cover pot fits this plastic grow pot perfectly!). Grow pots have lots of good drainage holes (preventing soggy socks) and are made of plastic (retaining soil moisture), so it’s a great combo for balancing the moisture level in the soil.
If you go this route, remove the fern/grow pot from the cover pot when you water it so the excess water can drain away. Then, just stick it back in the cover pot and you’ll have a nice happy fern.
5. How do you repot a crispy wave fern?
Once the roots of your crispy wave plant have filled it’s current container, you can repot it to the next size container. Since these are slow growing ferns, you won’t need to repot your plant very often.
You’ll know it’s time to repot your crispy wave fern if the soil seems to dry out very quickly (more quickly than normal) and you find yourself constantly having to water it.
You can also confirm it’s time to repot by removing the plant from it’s pot and examining the root system to see if it’s filling the container.
Repotting this fern is pretty straight forward. Just get the next size up pot and use the same soil mix we discussed previously (well draining with high peat content).
In my case, I repotted my crispy wave fern from a 6 inch pot into a clear plastic 8 inch pot (shown below). I like using clear pots when I can because it allows me to see the conditions of the soil and roots.
When repotting your fern, it’s important that the center crown of the fern is above the soil and not buried.
Add enough of your soil mix to the bottom of your new pot to get the center crown to the right height in the pot, and then fill in the sides with more potting mix (see images above and below). Water your crispy wave thoroughly after repotting and you’re finished!
Also, it’s best to wait until the growing season (April to September) to repot your crispy wave fern. If you repot in the winter while your fern is dormant, there’s more risk of stressing the plant roots.
6. How often should I fertilize my crispy wave fern plant?
Crispy wave ferns are slow growers, so they don’t need a lot of fertilizer. You can fertilize your plant approximately once per month during the growing season (April to September) with a dyna-gro 9-3-6 fertilizer diluted to half strength. Don’t fertilize during the rest of the year while the plant is dormant.
Also, don’t feel the need to fertilize your crispy wave fern right after you buy it. The nursery has probably already done this, so give it a month or two to adjust to it’s new environment.
If you fertilize your crispy wave and soon after notice problems such as brown spots or wilting, it’s probably been overfertilized. Discontinue fertilizing for a while and flush the soil by running water through the soil so that there’s a continuous stream draining out of the drainage holes for maybe a minute or so.
7. How do you propagate crispy wave ferns?
Crispy wave ferns cannot be propagated via root division like some other ferns. Instead, they are propagated by spores, which is a very long and difficult process.
Given that crispy wave ferns are relatively inexpensive, if you want more I recommend you just buy a crispy wave fern.
However, if you’re up for the challenge and are looking for a project that will last upwards of one year, check out the video below!
In this video, a fern spore propagation expert discusses exactly how you can grow ferns from spores.
8. Is crispy wave fern toxic to cats and pets?
Crispy wave ferns (Asplenium nidus) are not poisonous to cats, dogs, or humans according to the California Poison Control System. So that makes it a great pet-safe house plant.
9. Why is my crispy wave fern turning brown?
There could be a couple different reasons your crispy wave fern is turning brown.
- Underwatering. If you forgot to water your crispy wave fern or the soil has been drying out too much between watering, your fern may start to develop brown leaf tips. If underwatering continues for a long time, entire leaves could start turning brown and dying. Make sure to keep the soil evenly moist but not soggy.
- Low humidity. If you live in an arid area or run your A/C or heater a lot in your house, you may have low humidity, which will also cause brown leaf tips on your crispy wave fern. The best fix for this situation is to buy a humidifier and try to maintain a minimum humidity of 40-50% for your fern. Another option that is not as optimal but could work in a pinch is to place a pebble tray with water under your plant. Also, make sure your fern isn’t near the A/C or heat vent, as sudden drafts and temperature changes could hurt your plant.
- Too much sunlight. Crispy wave ferns will definitely turn brown if they are put in direct sunlight. These ferns like moderate, indirect sunlight. So, if your crispy wave fern is in front of a sunny window, move it back a bit to keep it out of direct sunlight.
10. How do you save a crispy wave plant?
If your crispy wave fern is dying or struggling, it is likely due to one of the following reasons: underwatering, overwatering, overfertilization, low humidity, or too much/too little light.
To save your crispy wave fern, you will have to first correct the underlying issue. You can refer back to each of the care sections discussed earlier in this article to determine which factor might be the problem.
After you correct the problem, you will have to be patient and wait for new growth to see if your fern will live. Once the fronds are damaged, they cannot be fixed.
HOWEVER, if you correct the issue and have patience, your crispy wave fern may grow new fronds and live to see another day.
11. Where can I buy a crispy wave fern?
Remember, make sure it specifically states that the plant is a ‘crispy wave fern’ because there are different varieties of Asplenium nidus and ‘birds nest ferns’.