Can Ferns Grow Indoors? Tips, Tricks, & How to Guide
- Pete Ortiz
- Last updated:
If your window sills are crowded with flowering plants and you’re looking for something different, ferns might be the perfect choice for you. They don’t have seeds or flowers, but they look great in any environment. Plus, ferns have a refreshing smell. The long, curly, and bright-green leaves, in turn, make them a sight for sore eyes.
More importantly, ferns can grow and thrive indoors. All you’ll have to do is water them frequently, make sure the soil is well-drained, rich, and mildly acidic, and protect them from the scorching sun. There’s a lot more to this, of course. So, let’s talk about the best ferns to grow indoors and how to care for them.
Botanical Name | Tracheophyta |
Soil Type | Well-drained, moist, organically rich, and sandy |
Soil PH | 4.0–7.0 (neutral) |
Sun Exposure | Indirect sun/partial shade |
Watering Requirements | Low/medium |
Temperature | 65–75º Fahrenheit |
Hardiness Zone | 2–10 USDA |
In Bloom | Late spring through fall |
Before You Start: The Best Fern Species to Grow Indoors
In the wild, ferns mostly grow in the shade, underneath tall trees with large branches. These plants have been around for 300+ million years and include 12K+ living species! And they are quite resilient, especially in areas with a warmer climate. However, if you want to grow them in your own house, you need to be very picky. Here’s a list of the most popular indoor ferns.
- Are you looking for a fast-growing fern? Then the Bird’s Nest fern (Asplenium nidus) will be a great choice. This species reaches 3–4 feet in height, flourishes in full sun, and is known for its flat fronds. In nature, it tends to grow on other plants but is also very well suited for indoor use.
- Asparagus fern (Asparagus aethiopicus) is just as tall (3.5–4 feet) and is perfect for hanging baskets. However, its sap can irritate the skin, so be careful with it. On the bright side, this lovely plant survives in almost all conditions and isn’t particularly fragile.
- Incredibly popular back in the Victorian times, the Sword fern (Nephrolepis) is still one of the most favored houseplants in the US. It is a hardy, robust plant with bright-green, toothed fronds that grow rapidly and require moderate care.
- Staghorn fern (Platycerium) will instantly grab your attention with those larger-than-average leaves that look like elk antlers. Easy to grow indoors, it is vulnerable to a fungal disease known as “black spot”.
- In contrast to most ferns, the Button fern (Pellaea) easily handles dry soil (soggy soil will be a problem, though). It’s a low-growing plant with round leaflets that looks lovely on windowsills.
- The Holly fern (Cyrtomium falcatum) leaves are quite sharp and resemble hollies (yes, hence the name). This plant flourishes in partial and even full shade and grows steadily in containers.
- Rabbit’s Foot fern (Davallia) is famous for the rhizomes that often hang over the container and make the plant look bigger. As long as it gets a healthy amount of indirect light, the fern will blossom. A go-to pick for hanging bots, it’s very tough and doesn’t need you to “babysit” it.
- If you live in a cloud area, go with the Maidenhair fern (Adiantum tenerum), as it thrives in low-lighting conditions. It’s a delicate plant, though, and won’t survive in a low-humidity environment.
- Need a fern to put in your bathroom? Then the Silver Lady fern (Blechnum gibbum) is what you need! It’s very tall and wide (36–48” x 24–36”), has a lovely smell, and grows best in moist soil.
Growing Ferns in Pots
As long as you’ve got a regular plastic pot, a bucket, some fertilizer, and a potting mix, you will be able to grow ferns indoors with ease. Start by putting a generous amount of potting mix and fertilizer (slow-release is the way to go here) into a bucket. Once the soil is mixed and ready, pour it into the pot. The pot should only be half-full.
If you have access to small gravel, put it at the bottom of the pot before adding the soil (for drainage). Alright, now grab the fern plant and place it into the pot and cover the roots with that same soil mix. Don’t forget to push the soil down a bit (very slowly and carefully) for it to set. Water the fern well, and that’s it!
How to Grow Ferns Indoors? (7 Tips)
1. Humidity Comes First
Ferns can’t survive without proper humidity levels—let’s start with that. So, when growing them indoors, see that the humidity level in the air is at 50%. Otherwise, the plants will slowly fade, turn brown, and maybe even drop leaves when forced to grow in dry conditions. The bathroom and the greenhouse are perfect spots for it. Your kitchen is also a great place for ferns to grow. However, in most rooms, humidity levels are as low as 5–10%.
Now, if you want to have the plants in a room that’s way too dry (like a bedroom), a humidifier is a must. These are available for $30–50 and do a decent job of keeping the room(s) nice and humid. Make sure it can run for at least 12 hours. Not ready to invest in such a device just yet? Then apply the so-called “misting” technique: that’s when you spray water from a bottle every 2–3 days to keep the plant moisturized (but not soggy).
2. How Much Water Do Ferns Need?
With ferns, the biggest mistake one can do is to let the soil get dry. So, don’t let too much time pass between the watering sessions. During the hot days (spring through summer), water the ferns generously, but in the winter, only water the soil until it gets a little moist. Be very careful not to get the roots soggy, as that will also kill the plants before long.
Touch the soil: it should be moist, but not overwhelmed by water. Make a habit of checking on the soil once or twice a day. When watering the ferns, keep pouring until you see the water escaping from the bottom of the pot. Oh, and it’s best to use lukewarm water. When it’s overly hot or cold, that can hurt the leaves.
3. Ample Light, But No Direct Exposure
Despite popular belief, ferns do need a healthy amount of light to flourish (especially indoors). True, they are deep shade plants, but that only means ferns don’t like exposure to direct sun. Therefore, make sure they get their fair share of light during the day to stay healthy. Pay extra attention to the leaves: if they’re turning brown, that’s a clear sign they’re getting more sun than they can handle.
To keep ferns away from scorching sun rays, place the pot on a windowsill that’s facing east or north, ideally a couple of inches away from the actual window. Can’t provide the plants with enough natural light? Consider using a gardening bulb. Also known as a grow light bulb, it will cost you $10–15. And one more thing: see that there aren’t any fans or vents around the plants, as they will suck most of the moisture out.
4. What About the Temperature?
As tropical plants, ferns like a warm climate but don’t tolerate extremely hot temperatures. When growing them indoors, the ideal temperature during the day will be 65–75º Fahrenheit. As for the night, aim for 55–65º. This means you’ll have to turn the thermostat on your furnace down a bit to make the ferns 100% comfortable. Or, you can keep it slightly higher (75–85), and the plants will adapt.
One thing that many gardeners miss is that during the winter, the temperature next to the windows is significantly lower than elsewhere in the room. Please keep this in mind and, if necessary, move the pots away from the windows: cold drafts have killed countless indoor plants! Ferns don’t do well in below-average temps, either (colder than 50º).
5. Choosing the Right Soil and Fertilizer
Alright, now let’s talk about feeding the ferns. The soil should be well-drained, well-aerated, moist, rich, yet not overly fertilized. Organic matter plays an important role in helping these plants thrive. Only use liquid or slow-release fertilizer but do it regularly (like 1–2 times a month). For most ferns, a 50/50 diluted mix should work.
This only applies to the growing season, though (April through September). In winter, it’s generally not recommended to use any compost, but each species is different. So, before you add any of that “magic mulch” to the pots, take a moment to learn exactly how much fertilizer certain fern types need. If you over-fertilize the soil, that will have a huge negative effect on the plants.
6. Light Pruning: A Necessary Procedure
Don’t underestimate the power of pruning! Leaves die—that’s a natural part of any plant’s life cycle. But if you trim them regularly, the ferns will be green and healthy 365 days a year. Keep an eye on the fronds: if some of them have turned brown, that means pruning is in order.
7. Repotting: Learn to Do it Properly
And what about repotting? It’s another nifty trick that will keep the plants healthy. Let’s say you’ve been growing ferns in a hanging basket or a pot for a while, and now it’s too small for it. To ensure rapid growth, you need to move it to a larger container. On average, this should be done once in 1–2 years. A younger fern species, in turn, might overgrow its original pot in 6–8 months.
When moving the plant, use fresh potting soil. Be very gentle with the roots! And remember, when the pot is too small, the plant will, most likely, be exposed to too much water. As a general rule, there should be at least a 1-2-inch gap between the roots of the fern and the container walls. Or you can just cut the fern into two pieces and plant the other half in a new pot.
Are Ferns Edible? What About Toxicity?
Yes, many fern species can be used as food, but not all of them. If you want to play it safe (which you absolutely should do), only eat the bracken, ostrich, and lady ferns. These have proven to be 100% edible. Unfortunately, many fern species are toxic both to humans and animals. The side effects include nausea, an upset stomach, skin irritations, and (minor) issues with the heart.
Do you have cats, dogs, or other pets in the house? See that the plants are outside of their reach. Be even more careful if you have little kids. The Boston, Holly, Bird’s Nest, and Maidenhair ferns are non-toxic and safe for children. With that said, many cultures use fern plants for medical purposes. Finally, they can be added to a compost bin and will enrich it with much-needed nutrients.
Related Read: How to Save Plants from Dog Urine: 5 Practical Options
My Ferns Are Wilting. What Am I Doing Wrong?
In nature, ferns grow in rainforests with above-average humidity levels and limited exposure to the sun (but lots of indirect light). The large trees protect them from UV rays and sun rays. So, your goal as an indoor gardener is to recreate these conditions as closely as possible. Plus, as we learned earlier, consistent watering is the key to growing these beautiful plants indoors. Too much or too little of it will make the fronds drop.
Do this right, and the ferns will have a long and prosperous life. A common mistake is when people add too much fertilizer in hopes of cultivating growth. Don’t overdo it with the mulch! Another thing you can do is move the plants outside to cultivate natural growth. Find a sheltered spot in the garden that doesn’t get too hot or cold. Do this in early summer and bring the ferns back before the first frost.
See also: 8 Expert Tips on How to Mount a Staghorn Fern & Tips for Growing
Conclusion
Ferns are quite fascinating. They instantly grab the attention, thanks to the lush foliage, and add an “exotic” touch to your indoor garden. If you want to see them flourish and prosper, you need to do two things. First, make sure you pick the right species. Second, follow our instructions on watering, sun exposure, soil, fertilizing, and pruning closely to achieve the best results.
Humidity and lighting should always be your #1 priority, as these two factors can make it or break it for most ferns. As long as you choose wisely and take proper care of the plants, you’ll be very successful in growing ferns in your home. These plants are pretty tough, despite their delicate nature.
See also: Is My Fern Dead? (9 Signs to Look For)
Featured Image Credit: MabelAmber, Pixabay
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