Boston Fern

Nephrolepis exaltata 'Bostoniensis'

Also called sword fern

A big, soft fountain of feathery fronds spilling over the pot. Known for old-fashioned charm, and for sulking when the air gets dry.

Foe

1.6/5

how easy it is to care for

2.8/5

how much it stands out visually

: Bright shade

A few feet from a window, with sun kept off the fronds

A few feet from an east window suits it, or a spot behind a sheer at a south or west one, as long as sun stays off the fronds. Farther back it copes, though it grows thinner and drops leaflets; with no window it fades.

An east window suits it, or a spot behind a sheer curtain in a south or west one (UW–Madison Extension).

It copes with a dim room, but it grows thinner there. With no window at all, it slowly fades.

: Weekly+

About every 2-4 days in summer; dry soil makes it shed

Soak it about every 2-4 days in summer and 4-7 in winter so the soil stays evenly moist, since dry soil sets off shedding. Soggy winter soil can rot the roots, though, so empty the saucer.

Water until it runs out the bottom and empty the saucer: moist, never soggy, and never dried out. NC State Extension says the soil should never be allowed to dry out, and to water a little less in winter, when soggy soil can rot the roots. In summer heat, setting the pot inside a slightly bigger one helps it hold moisture (UW–Madison).

Gone for a while? Five days is about its limit, even after a good soak; for longer, ask someone to water it.

: Medium

A fast fountain of fronds, 2-3 feet tall and wide

Fronds rise from the center and arch over on every side, filling out fast into a fountain 2-3 feet tall and wide. It looks best spilling from a hanging basket or a tall stand.

Growth is fast: new fronds keep coming from the center. Cut old or bare fronds off at the soil; UW–Madison Extension says that encourages new ones.

: Pet & kid safe

Safe for pets and kids alike if chewed

DogsSafe
CatsSafe
KidsSafe

A safe pick for a home with chewers: the ASPCA lists it as non-toxic to dogs and cats, and CHOP puts it on its nonpoisonous list for kids. A cat batting at the dangling fronds is harder on the fern than on the cat.

Kids too: it’s on the nonpoisonous plant list from the poison control center at Children’s Hospital of Philadelphia. Cats sometimes bat at the dangling fronds, which is harder on the fern than on the cat.

ASPCA: safe for dogs.
ASPCA: safe for cats.
CHOP: safe for kids.

Cats and dogs: The ASPCA lists it as non-⁠toxic.

Kids: CHOP lists it as non-⁠poisonous.

: Humid

Away from vents and drafts, in your most humid room

A room at 50-70°F suits it, away from heating vents and cold drafts, with humid air of 50% or more. Dry winter heat browns the leaflet tips and sets off shedding, so give it your most humid room, often a bathroom.

Temperature: 50-70°F
Humidity: 50%+

: Scale, spider mites

Scale on the frond stems; spider mites in dry air

Scale shows as small brown bumps along the frond stems, not the neat rows of spore dots underneath, and spider mites leave fine webbing when the air is dry. Mealybugs, like white cotton, hide in the center.

Scale
Spider mites
Mealybugs

Few pests; dry air is what invites them.

Scale looks like small brown bumps stuck along the stems of the fronds (not the neat rows of dots underneath, which are spores). UW–Madison Extension’s fix is simply to cut the infested fronds off at the soil.

Mealybugs look like tufts of white cotton down in the center. Dab them with a cotton swab dipped in rubbing alcohol, then check again next week.

Spider mites leave fine webbing and a dusty, speckled look when the air is dry, per NC State Extension. Rinse the plant in the shower, undersides of the fronds included, and raise the humidity.

: More

Sweep up leaflets and snip brown fronds; feed in season

Sweep up shed leaflets and cut brown or bare fronds off at the soil, which encourages new ones. Feed at half strength every 4-6 weeks as it grows, trim stray runners, and repot or divide in spring once it fills its pot.

Feeding6× a year
Sweep shed leaflets12× a year
Cut out dead/brown fronds6× a year
Trim runners2× a year
Repot or divide1× a year

A mix that holds moisture but still drains fast (UW–Madison suggests peat with vermiculite), in a pot with a drainage hole.

It grows fast and fills its pot. Repot or divide it every few years, in spring.

Food is optional: a houseplant fertilizer at half strength every 4 to 6 weeks while it’s growing is plenty, and much less in winter. Too much browns and dries the ends of the fronds.

: Simple

Soft, feathery fronds in one matte green

Long, finely cut fronds, up to 2-3 feet, in one plain matte green. They spill over the rim in a soft, feathery mass with old-fashioned charm, leaving the soil partly hidden.

Where to find me

Not at PILF places

Fun fact

'Bostoniensis' turned up in 1894 in a fern shipment from Philadelphia to Boston, which is where the name comes from.

Designer tips

A Victorian-parlor classic that looks lush and modern hanging in a bright window.

The styleFronts a turn-of-the-century porch or a tall fern standFound in 1894, it was a favorite by the early 1900s, the era of deep front porches and pedestal fern stands, and a tall stand still shows off the full fountain best.

The seasonSpends summer on a shady porch, winter by a windowIt loves humid summer air on a covered porch, then comes in before nights drop toward 50 to sit a few feet from a window, ideally in a steamy room.

Troubleshooting

It’s dropping little leaflets everywhere

Dry air or dry soil, usually both. A soak about every 2-4 days in summer keeps the soil evenly moist, and a bathroom spot or a humidifier nearby adds the humid air it likes. Cut bare fronds off at the soil if they bother you; new ones fill in.

Why are the frond tips turning brown?

Dry air, most often: UW-Madison Extension notes the tips and edges brown in dry conditions, especially in winter, and too much fertilizer does it too. Trim the brown bits if you like and raise the humidity; the fern carries on either way.

Why are some fronds turning yellow?

An old frond yellowing now and then is normal; cut it off at the soil. Lots of yellow with soggy soil likely means too much water, most often in winter, so let the surface dry a little between soaks and empty the saucer.

See all 9

Long, leafless strings are hanging down

Runners. They root into new plants wherever they touch soil, so snip them off, or pin one onto a small pot of damp mix and cut it free once it grows fronds of its own.

What are the brown dots under the fronds?

Spores, in neat rows: they’re how ferns reproduce, and NC State Extension says not to mistake them for insects or disease. Scale looks different, as scattered brown bumps along the frond stems.

Can it live in a dim room?

It copes, though it grows thinner and drops leaflets there. A room with no window is too little light for it, and it slowly fades.

My cat chewed a frond

Nothing harmful: the ASPCA lists Boston fern as non-toxic to cats and dogs, and it’s on CHOP’s nonpoisonous list for kids. As with any plant, a big nibble might upset a stomach.

I’m going away for a week

Five days is about its limit, even after a good soak, so for a longer trip, ask someone to water it.

Can it go outside for the summer?

Yes, in shade, once there’s no danger of frost; a covered porch suits it. Bring it back in before nights drop below 50°F, check it for bugs, and expect some shedding while it gets used to drier indoor air.

Propagation

Yes, two ways, and both are easy.

Division is quickest: in spring, ease it out of its pot and cut the root ball in half or quarters with a sharp knife, then pot each piece.
Or use its runners, the thin, leafless strings it sends out: UW–Madison Extension notes they root into new plants wherever they touch soil, so pin one onto a small pot of damp mix and cut it free once it grows fronds of its own.