Button fern (Pellaea rotundifolia) terrarium care
The most forgiving terrarium fern. Why beginners should start here, and how to keep it happy for years.
If you’re going to put a fern in your terrarium, start with button fern. It’s the most forgiving fern for the closed-jar environment.
Quick facts
| Botanical name | Pellaea rotundifolia |
| Common names | Button fern, round-leaf fern |
| Light | Low to medium indirect |
| Humidity | 60%+ |
| Water | Evenly moist |
| Difficulty | Beginner |
Why it’s the best beginner fern
- Tolerates drier conditions than most ferns
- Round, leathery leaves resist crispy edges
- Slow grower (won’t outgrow your jar)
- Tolerates low light better than most ferns
- Doesn’t drop leaves dramatically when stressed
Care
Light
Low to medium indirect. North windows are ideal. East windows work.
Avoid direct sun — leaves will crisp.
Water
In a closed terrarium: rarely needs water. Mist occasionally.
In an open terrarium: water when top of substrate is dry. Tolerates brief dry spells.
Humidity
Tolerates 60%+, but doesn’t need the extreme humidity maidenhair requires. Good for slightly-open terrariums.
The look
Button fern has small round leaves on wiry dark stems. Looks delicate but isn’t. Adds textural contrast to moss and fittonia.
Common problems
Brown leaves
Cause: Underwatering or low humidity Fix: Water thoroughly, mist more, or close the jar
Yellow leaves
Cause: Overwatering OR old age Fix: Check moisture, remove yellow leaves
Leggy growth
Cause: Not enough light Fix: Move to brighter spot
Where to buy
Widely available at nurseries. Often in the houseplant section, not the terrarium section. Any small button fern will work.
Pairing
Button fern works with:
- Sheet moss (ground cover)
- Pilea glauca (round leaves of a different color)
- Selaginella (moss-like texture)
For more ferns, see our ferns guide.