Houseplant · Nephrolepidaceae
Boston Fern
Nephrolepis exaltata
Keep the air humid and the soil evenly moist, and your Boston fern turns into a soft green fountain.
Bright indirect
61–70°F · 16–21°C
USDA 10–12
2–3 ft · 0.6–0.9 m
Overview
If you've never kept a fern before, the Boston fern is a pretty easy one to start with, and people love it for those arching fronds that spill over the side of a pot or hanging basket. It's part of the genus Nephrolepis and grows wild in steamy tropical forests, so guess what it still wants indoors? Warm, damp air. Give it a bright spot out of direct sun and it'll take off, filling out into a big, soft green mound.
Really, it asks for two things: steady moisture and high humidity, which happen to be the two things regular indoor air doesn't have much of. Let it dry out or park it next to a heater and it'll let you know right away, dropping leaflets and browning at the tips. But keep the soil evenly moist and the air humid, and it'll forgive just about anything else you do.
It's a great pick if you've got pets or kids, because the ASPCA lists it as non-toxic. So this is one of those rare houseplants you can grow without worrying about a curious nibble, and honestly, it's a good-looking one too.
Care
The short version: bright indirect light, soil that stays evenly moist but never soggy, and humid air around 61°F to 70°F (16°C to 21°C). Feed it monthly while it's growing, and split the clump every few years.
Light
Give the fern bright, indirect light, like the spot near a window but out of the direct sun. It'll also handle medium light, partial shade, and even full shade, so a dim corner won't do it in, but strong sun? That'll scorch the fronds.
Water
Keep the mix evenly moist but never soggy, and only back off a little in winter. Let it dry out and the fern starts dropping leaflets and browning at the tips, so honestly, watering it consistently matters more than anything else.
Soil
Go with a peaty, soil-based mix that drains well but still holds onto moisture, like a peat and vermiculite blend. That combo keeps the roots damp without leaving them sitting in water, which is exactly what you're after.
Temperature
The fern's happiest between 61°F and 70°F (16°C to 21°C), so basically normal room temperature. Just keep it away from cold drafts and the dry heat coming off radiators, since both of those dry the fronds out.
Humidity
This is a high-humidity plant, and dry indoor air is what it hates most. Boost the moisture around it by double potting or sitting the pot on a tray of wet pebbles, which works a lot better than misting does.
Feeding
Feed it monthly from spring to early fall while it's growing, then stop over winter. Use a weak, half-strength liquid feed or a slow-release houseplant fertilizer, because a strong dose will scorch the roots.
Pruning
Cut old or damaged fronds off at the soil line to make room for new growth. And if the plant's dried out and shed, you can cut the fronds back to about 2 inches and let it regrow from the base.
Repotting
Divide the fern every few years in spring, once the clump has filled its pot. Keep an eye out for roots circling the container and crowded fronds that have lost their pep, both of which mean it's time to split and refresh.
Size & spacing
Indoors it gets to about 2 to 3 feet (61 to 91 cm) tall and just as wide, so give it room to arch. Those spreading fronds look best where they can drape, like in a hanging basket or up on a stand.
Troubleshooting
Just about every Boston fern issue comes back to dry air, dry soil, or a stray pest that hitched a ride. The good news? The fronds show you the early signs, so you can jump in before the plant really starts shedding. Find what matches what you're seeing below, then fix it while it still does some good.
Browning fronds, and little leaflets all over the floor
Seeing crispy tips and a trail of leaflets? That's almost always dry air and dry soil talking, and the browning shows up at the leaflet tips first, before the fern really starts to drop. Keep the mix evenly moist, bump up the humidity with a pebble tray or by double potting, and shift the plant away from radiators and drafts. If it's dried out badly, you can cut the fronds back to about 2 inches and let it grow back fresh.
Fix:
- Keep the potting medium evenly moist but not saturated
- Raise humidity by double potting or setting the pot on a tray of wet pebbles
- If badly dried out, cut fronds back to about 2 inches to regenerate
Sticky fronds with cottony fluff or tiny bumps
Those bumps and bits of cottony fluff are scale insects or mealybugs, and that sticky shine they leave is honeydew. Snip off and toss any fronds that are really overrun, then treat whatever's left. It helps to give every new plant a once-over before it joins the rest, and to keep a buggy fern off on its own until it's clean again.
Fix:
- Remove and discard heavily infested fronds
- Treat remaining foliage for scale or mealybugs
Toxicity
Got pets or kids? Good news: the Boston fern is safe. The ASPCA lists it as non-toxic to cats and dogs, and there's no toxic compound reported in the plant, so it can sit right where curious animals and children can reach it.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Cats are totally fine here. The ASPCA calls Boston fern non-toxic to them with no toxic principle on record, so if your cat sneaks a nibble, there's nothing to stress about.
Dogs None
Dogs get the all-clear too. The ASPCA lists this fern as non-toxic to them, so a chewed-up frond won't poison your pup.
Horses Safe
There's no toxic compound on record in the plant, so if a horse grazes a frond, there's no poisoning risk to worry about.
Rabbits Safe
A rabbit can nibble the fronds and be just fine, since the fern isn't toxic. That said, regular greens still make a better everyday food than fern leaves.
Livestock Safe
Cattle, goats, and sheep won't hit any toxic principle here, so a mouthful off a stray plant is no big deal.
Birds Safe
The fronds carry no known toxin, so this fern is a safe bit of green to have around birds.
People Safe
Boston fern is harmless to people, so a little one who mouths a frond is fine. It's not a food plant, though, so there's nothing on it actually worth eating.
Varieties
There are a handful of named cultivars you'll run into most, and they mostly differ in size, frond texture, and color. Here are the ones worth knowing.
'Bostoniensis'
This is the classic Boston fern everyone pictures, with arching fronds that get to about 4 feet long and 6 inches wide.
'Compacta'
Basically a neater, smaller version of the usual fern, which is handy when you're short on space.
'Florida Ruffle'
Its fronds are fuller and more finely cut, so the whole plant ends up looking soft and ruffled.
'Rita's Gold'
This one's grown for its new leaves, which come in a bright chartreuse to golden-green.
How to propagate
Making more Boston ferns is easy, and honestly the plant does most of the work for you through dividing clumps and self-rooting runners.
DivisionEasy
Spring · A few weeks to a couple of months to root and resume growth
Want more ferns? Splitting the clump is the easiest way to get them. In spring, cut the root ball straight down into halves or quarters, hang onto as many fronds as you can on each piece, and then just give the divisions a few weeks to a couple of months to root and pick back up. The fern also spreads by itself through runners that root wherever they touch soil, and out in the wild it grows from spores tucked under the fronds.
Offsets & pupsEasy
Spring to summer · Several weeks once a rooted runner is separated
The fern sends out runners that sprout little plantlets anywhere they hit moist soil. Once a runner has rooted, just snip it off the parent in spring or summer, and the new plant gets going within a few weeks.
Myths
Boston fern is poisonous to cats and dogs like so many houseplants.
Nope, this one's safe. The ASPCA lists Boston fern as non-toxic to both cats and dogs, so it gets a spot in homes where a lot of other houseplants just can't go.
Misting is the best way to give a Boston fern the humidity it craves.
Misting actually does very little for humidity, and it leaves the fronds damp, which is exactly what foliar leaf spot likes. Double potting or a pebble tray bumps up humidity way more reliably, and it keeps the leaves dry while it's at it.