Houseplant · Pteridaceae
Button Fern
Pellaea rotundifolia
Tougher than it looks, the button fern just wants bright shade and an easy hand on the watering can.
Bright indirect
Every 5–10 days
50–77°F · 10–25°C
USDA 9–11
Overview
Think of the button fern as the laid-back one in a family that's usually high-maintenance. Where does the name come from? Those rows of small, round, glossy leaflets that run like little buttons down each arching frond, all sitting on dark, nearly black stems. It stays small and hardly ever tops a foot, so it slots right onto a shelf, a desk, or a bathroom windowsill.
Here's the part that surprises people: it doesn't fall apart the second things dry out. Most ferns do, but this one comes from rocky, well-drained ground, so it'll take a skipped watering in stride. That, plus the fact that it's fine in regular room conditions, makes it one of the easiest ferns to keep going indoors.
Give it bright, filtered light and soil that drains well, and honestly it mostly takes care of itself. There are really only two ways to lose it, and they're opposites: letting the rootball dry out to a crisp, or leaving it sitting in water. Stay in the middle and you'll get slow but steady growth for years.
Care
The short version: bright indirect light, soil that drains well, and a drink once the top of the mix has dried a bit. It's happy with normal room warmth and humidity, and a half-strength feed through spring and summer keeps it nice and green.
Light
Go for bright but indirect light, like near an east window or a few feet back from a brighter one. Only have a medium or even kind of dim spot? It'll still hang in there, just slower. Just keep it out of harsh direct sun, since that bleaches and scorches the fronds.
Water
Let the top of the soil dry out a little before you water again, which lands around every 5 to 10 days depending on the time of year. It's more forgiving of a missed drink than most ferns, but don't let the whole rootball go bone dry, or the frond tips will brown. And tip out whatever pools in the saucer.
Soil
Pop it in a well-drained, peat- or humus-based mix with some extra perlite or sand mixed in for air. It's easy about pH, happy anywhere from 6.0 to 7.5, so most regular potting soils work fine as long as water actually runs through.
Temperature
Normal room warmth is spot on, somewhere between 50°F to 77°F (10°C to 25°C). Just keep it clear of cold drafts and the hot, dry blast off a radiator or heating vent, because both of those stress the fronds.
Humidity
Shoot for 40% to 60% humidity, which is about what most homes already have anyway. It handles average air better than the fussier ferns, but if your place runs dry, a kitchen or bathroom spot, or a pebble tray nearby, keeps it looking its best.
Feeding
Feed it monthly through spring and summer with a balanced water-soluble fertilizer cut to half strength. That's plenty for such a slow grower, and you can skip feeding entirely through the dark, dormant months.
Pruning
There's no real pruning to do. Just snip off any faded, browned, or beat-up fronds at the base to keep it looking tidy and make room for new growth.
Repotting
Repot it every 2 to 3 years in spring, or sooner if roots are poking out the drainage holes, the soil dries out weirdly fast, or the fronds are crowding the pot rim. Just bump up one pot size and use fresh, free-draining mix.
Size & spacing
It's a compact little thing, only 6 to 12 inches (15 to 30 cm) tall with about the same spread. That tiny footprint is exactly why it's such an easy plant to park on a shelf or table.
Troubleshooting
Just about every button fern problem comes back to water, either too little or too much, and the fronds will basically tell on you. Find the one below that looks like yours, tweak things, and sort it out before it spreads to the whole plant.
Yellow fronds with soft, mushy stem bases
Yellow fronds and soft bases? That's usually overwatering and root rot, the one thing this fern won't put up with. Soggy, poorly drained soil chokes the roots until they go black. Let the soil dry out more, dump any water sitting in the saucer, and if the roots already feel mushy, repot into fresh well-draining mix and trim off the rotted bits.
Fix:
- Allow the soil to dry further before the next watering
- Repot into fresh well-draining mix and trim away rotted roots
- Ensure the pot has functioning drainage holes
Fronds turning brown and crispy
Brown, crispy fronds almost always mean the plant got too dry. It handles a missed watering better than most ferns, but let the rootball dry out all the way and the fronds will let you know. Dry air from a nearby radiator or vent does the same thing, so move it off the heat and water it before the soil totally dries out.
Fix:
- Rehydrate thoroughly, including bottom-watering if the rootball has dried out
- Move away from radiators, vents, and direct sun
- Maintain a more consistent watering schedule
Pale, bleached, or scorched fronds
See faded, dry patches on the side facing the window? That's direct sun scorching the fronds. This fern wants bright but filtered light, not the harsh midday stuff. Just move it back from the glass into bright indirect light and trim off whatever's too far gone.
Fix:
- Relocate to a spot with bright indirect light
- Remove badly scorched fronds
Toxicity
Got pets? Good news: the button fern is fine to keep around cats, dogs, and everybody else at home. The ASPCA calls it non-toxic, and no part of it carries a known poison. Sure, a nibble might upset a little stomach the way any plant can, but there's nothing here to actually worry about.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
The ASPCA lists the button fern as non-toxic to cats, so a curious nibble won't poison them. If a cat really pigs out on any plant it might bring up a hairball or some undigested greenery, but that's just a full stomach, not a toxin.
Dogs None
Dogs are in the clear here too, since there's nothing toxic in the fronds. A pup that chews a frond is fine, though a big mouthful of any houseplant can leave the stomach a little unsettled for a bit.
Horses None
There's nothing in this fern that's known to hurt horses. It's not a forage plant, but a random taste is no big deal.
Rabbits None
Rabbits can munch the fronds without any poisoning worry. Like with any new green, just give them a little at first so their gut can ease into it.
Livestock None
Goats, sheep, and other livestock have nothing to fear from this fern, which grows as a small houseplant anyway, not something out in a pasture.
Birds None
Pet birds can perch on or peck at the fronds no problem, since nothing in the plant is toxic to them.
People None
The button fern is harmless to people and totally safe around kids. Nobody grows it to eat, so there's no reason to taste it, but an accidental nibble won't do any harm.
No special handling precautions are required.
Varieties
You'll pretty much always run into this one as the plain species, so there's no big list of named cultivars to wade through. What you see on the shelf is what you get.
Pellaea rotundifolia (species)
You can spot the true species by its arching fronds lined with small, glossy, round leaflets like little buttons, all running along dark, wiry stems.
How to propagate
Want more button ferns? Splitting an established clump is the easy way, and it hands you grown plants in a few weeks instead of the long wait you'd get from spores.
DivisionModerate
Spring, ideally at repotting · 4 to 8 weeks
The easiest way to make more is just to split the plant in spring, ideally while it's already out of the pot for repotting. Tease the rootball into clumps, leave a good chunk of roots and a few fronds on each piece, and those divisions will settle into fresh growth over the next 4 to 8 weeks. You can grow new ones from spores off a mature frond too, but that's slow and finicky, so most home growers don't bother.
Myths
The button fern needs constantly soggy soil like other ferns.
Nope, this one breaks the fern rules. It deals with drought way better than its cousins and actually likes the soil surface to dry out a bit between drinks. Keep it soggy all the time and the roots rot, so go easy.
All ferns are dangerous to cats and dogs.
Plenty of common ferns are totally safe, and this is one of them. The ASPCA lists Pellaea rotundifolia as non-toxic to both cats and dogs, so it's a solid pick for a home with pets.