How to Care for Nephrolepis exaltata (Boston fern)
Korean name: 보스턴 고사리
This fern has lush, cascading leaves and is highly effective at removing formaldehyde, ranking among NASA's top air-purifying plants.
Key facts
- Category: Foliage plant
- Family: Nephrolepidaceae
- Difficulty: Moderate
- Where to keep: indoors or outdoors
- Native to: Tropical regions
- Growth rate: Moderate
- Pets: No known toxicity, so it is fine to keep around pets.
- Air purifying: Helps clean indoor air.
- Traits: fern, air purifying, NASA recommended, humidity loving
- Also known as: Boston fern, Sword fern
Care Guide
- Light: Indirect light. Avoid direct sunlight.
- Watering: Water frequently to keep the soil consistently moist.
- Soil: Moisture-retaining peat moss mix
- Humidity: High humidity required (above 50%)
- Temperature: 16~24°C
- Fertilizer: Diluted fertilizer every two weeks from spring to summer
Detailed care guide
Boston fern is a foliage plant known for its lush, cascading fronds, and it helps purify indoor air.
Watering
Water it often enough to keep the soil consistently moist. Watering about every 3 days helps keep it from drying out. Overwatering turns the leaves yellow and mushy, while dryness causes the leaf tips to brown.
Light
It likes bright indirect light, and avoiding direct sun is important. Prolonged direct sun exposure can scorch the leaves. Without enough light, the stems stretch out and the whole plant looks weak.
Humidity
High humidity is essential — keep it above 50%. If indoor air is dry, the leaf tips can dry out and discolor. Frequent misting also helps.
Temperature
Keeping the temperature between 16–24°C helps it grow well. If it's too cold or the temperature changes suddenly, growth can stall or the leaves can be damaged. Keep it in a comfortable indoor temperature.
A common first-timer mistake
Giving it too much water all at once is a common mistake. Keep the soil consistently moist, but don't let water pool in the pot.
If you have pets
Boston fern is not known to be toxic to pets. That said, eating a lot of any plant can cause stomach upset, so if your pet chews on it habitually, move the plant out of reach.
Season by season
In spring and summer, growth speeds up, so water regularly to keep the soil from drying out. During this period, a diluted fertilizer every two weeks helps. In fall and winter, growth slows, so cut back a bit on the amount of water.
Common problems and fixes
Too little water causes the leaf tips to dry out and brown, while overwatering can turn the leaves yellow or mushy. If light is too weak, the stems grow long and weak. Low humidity dries out the leaves, so manage humidity through misting.
Repotting and propagation
Repot when the roots have become crowded or drainage has worsened. Propagation is mainly done through root division. After repotting, using a peat-moss-based potting mix that holds moisture well is a good idea.
Who it's a good fit for
This plant suits anyone interested in purifying indoor air, or who prefers lush, green foliage. It's a great fit for partially shaded spaces, or homes and offices that can maintain high humidity. It's especially recommended for those already somewhat experienced with plant care.
Written by AI from the care facts in this entry. Treat it as a starting point.
Common questions
How often should you water Nephrolepis exaltata?
Water frequently to keep the soil consistently moist. Roughly every 3 days is the baseline; adjust for the season and the spot it sits in.
Where should you keep Nephrolepis exaltata?
It likes Indirect light. Avoid direct sunlight.. You can grow it indoors or outdoors. Use Moisture-retaining peat moss mix.
Is Nephrolepis exaltata safe around pets?
No known toxicity, so it is fine to keep around pets.
Is Nephrolepis exaltata good for beginners?
Difficulty: Moderate. Keep it around 16~24°C. Humidity: High humidity required (above 50%). Fertilise Diluted fertilizer every two weeks from spring to summer.