Bird’s nest ferns (Asplenium nidus) are native to tropical rainforests, thriving in warm, humid conditions. This means an ideal temperature range of 70 to 80 degrees Fahrenheit in the home, avoiding temperatures below 60 degrees F. Ideal indoor humidity won’t drop much below 50 percent. This guide will detail what you need to know about bird’s nest fern temperature and humidity tolerance indoors so you can decide if this houseplant is right for you.
- Native Temperature and Humidity Ranges Bird’s Nest Ferns Receive
- Signs Your Plant is Exposed to the Wrong Temperature and Humidity
- How Warm is Too Warm for Bird’s Nest Ferns?
- Ideal Temperature and Humidity Considerations
- Best Locations for Bird’s Nest Ferns Indoors
- How to Boost Humidity in Your Home
- Caring for Bird’s Nest Ferns in Spring and Summer
- Caring for Bird’s Nest Ferns Over Winter
Native Temperature and Humidity Ranges Bird’s Nest Ferns Receive
Bird’s nest ferns are native to tropical regions of Australia, Southeast Asia, the Pacific Islands, and Madagascar. Here, these glossy ferns thrive in the warm, humid climate of the rainforest. They’re epiphytic and are often found growing on tree trunks, rotting logs, and wooden structures.
In their native habitat, the ferns thrive in frequent rainfall. However, their epiphytic nature means they don’t thrive with wet feet. Though bird’s nest ferns prefer a moist growing substrate, they don’t like sitting in standing water. In the home, you can replicate these conditions by providing moist soil that’s well-draining and never wet (see our guide to watering Bird’s Nest Ferns for more).
Emulate tropical humidity by misting the ferns regularly. Alternately, place fern containers on a dish filled with pebbles and water. As the water evaporates, it increases the humidity around the plants.
You may also choose to place ferns in naturally humid parts of the home, such as a bathroom, kitchen, or laundry room. If you live in an arid region, you may have to take further steps to emulate native growing conditions, such as running a humidifier near your plant.
Bird’s nest ferns’ native habitat has year-round warm temperatures, too. In the home, this translates into consistent temperatures between 70 and 80 degrees F. Anything colder than 60 degrees can be detrimental to a fern’s health.
Signs Your Plant is Exposed to the Wrong Temperature and Humidity
Though bird’s nest ferns can stand short dry or cold periods, they can’t thrive in these conditions for very long. Temperature fluctuations under 60 degrees or constant low humidity are especially problematic.
Signs your bird’s nest fern is too cold or the air in your home is too dry include browning at the edges of fronds. If you notice fronds turning brown at the margins, regularly place the plant in a warm spot and mist to increase humidity levels.
Dry conditions can also lead to tip burn or necrotic frond tips. If you notice dead areas on the tips of your fern’s fronds, increase the humidity level around the plant by misting regularly and placing it on a tray filled with pebbles and water. Check to ensure the soil stays consistently moist.
How Warm is Too Warm for Bird’s Nest Ferns?
Though bird’s nest ferns love warm, humid conditions, there’s such as thing as too warm and too humid. Pale, yellowish fronds may indicate your plant is too warm; this often happens if a bird’s nest fern is placed in a spot that receives bright, direct light. Move the plant into a shadier part of the home where temperatures remain between 70 and 80 degrees to avoid yellowing, pale foliage.
If you notice mold developing on the soil surface of your bird’s nest fern container, the plant may be in a spot that’s too humid. Using a chopstick, gently poke holes into the soil, focusing on the area between the container’s edge and the plant. This can help aerate the soil and reduce humidity.
When a fern’s environment is too warm or humid, it’s susceptible to developing blight. Caused by a bacterial pathogen, blight leads to small spots on foliage. First, spots look water-soaked, then they turn brown and purple. The spots grow and spread along the fern’s veins if conditions remain warm and wet. Prevent blight by eliminating watering from above and keeping fronds dry.
Ideal Temperature and Humidity Considerations
The ideal temperature and humidity for a bird’s nest fern are in a tropical rainforest. Of course, an indoor plant doesn’t live in a tropical forest, but you can mimic those conditions.
Optimal temperatures for a bird’s nest fern range year-round between 70 and 80 degrees F. The plants can handle slightly higher temperatures but struggle below 60 degrees.
As for humidity, 50 to 60 percent is a good target range. Ferns can tolerate an occasional dip but don’t let the level stay below 30 percent for too long. Slightly higher humidity won’t hurt your plant.
Monitor ambient temperatures and humidity in your home with a hygrometer. These handy portable devices measure both temperature and humidity. You can move them to different parts of the room to determine the conditions in each specific site.
Best Locations for Bird’s Nest Ferns Indoors
When determining where to place your bird’s nest fern, keep light and drafts in mind. Window placement is key. Bird’s nest ferns thrive in medium indirect light. Often, this translates to a north-facing window, near an east-facing window, filtered light through a sheer curtain, or even a lightly shaded part of the room.
Because your fern needs consistent moisture, keep bird’s nest ferns away from any drafts. This may mean doors, windows, radiators, or HVAC registers.
How to Boost Humidity in Your Home
In a perfect world, your home’s humidity stays between 30 and 50 percent. In the real world, humidity can be much lower or higher.
Bird’s nest ferns thrive at or around 50 percent humidity. They also enjoy the higher humidity often found in bathrooms, kitchens, and laundry rooms. However, these tropical plants struggle when humidity falls below 40 or 30 percent.
Luckily, there are ways to increase humidity. Placing the fern’s container on a tray or dish filled with pebbles and water is simplest. As the water evaporates, the air around the plant remains humid.
Misting the fern can help. However, this only increases humidity temporarily, and you’ll have to remember to mist consistently.
You may also choose to run a small humidifier near your plant. Just be careful not to let the area get too humid, which may encourage mold growth.
Caring for Bird’s Nest Ferns in Spring and Summer
If you live in a region with hot, dry summers, consider boosting the humidity around your bird’s nest fern with a pebble tray or a small humidifier. Move plants away from south- and west-facing windows, which may let in intense light during the summer.
Keep plants away from A/C vents, as well. The cool air can lower temperatures too much and cause soil to dry out. Lightly fertilizing your Bird’s Nest Fern in spring and summer can also boost growth, and consider pruning and trimming the plant periodically.
This is also the best season to consider propagating your bird’s nest fern or repotting if needed.
Caring for Bird’s Nest Ferns Over Winter
During the cooler times of the year, indoor heating may cause air and soil to dry out faster. Consider a humidifier or pebble tray to keep humidity at consistent levels. Keep plants away from heating vents and registers.
Finally, ensure ferns receive enough light when days grow shorter; a north-facing or east-facing window may be a good choice. Just be aware of potential cold drafts.
While bird’s nest ferns aren’t difficult to care for, they grow best in conditions that (somewhat) emulate their native habitat. This includes temperatures that stay between 70 and 80 degrees F year-round and consistent humidity that doesn’t drop below 40 to 50 percent. With a bit of care, you can create a comfortable environment in which your bird’s nest fern can thrive.
Linsay is an American copywriter based in the Pacific Northwest with a background in academic writing and research. Linsay holds Master's degree in both Anthropology and Library and Information Sciences and has written for numerous national and international publications including USA Today, SFGATE, Hunker, and The Bump across an array of topics in the gardening, green living, and travel sectors. When she's not writing, you'll usually find Linsay reading, kayaking, sailing, snowboarding, or working in her garden.