Houseplant · Nephrolepidaceae
Boston Fern
Nephrolepis exaltata
Keep the soil evenly moist and the air humid, and the Boston fern erupts into a fountain of soft green fronds.
Bright indirect
61–70°F · 16–21°C
USDA 10–12
2–3 ft · 0.6–0.9 m
Overview
The Boston fern is one of the most rewarding ferns to grow indoors, loved for arching fronds that pour over the rim of a pot or hanging basket. It sits in the genus Nephrolepis and grows wild in steamy tropical forests, so it still chases that same warm, damp air on a windowsill. Drop it into a bright spot out of direct sun and it takes off, packing out into a thick green mound in no time.
Give it the two things it really chases, steady moisture and high humidity, and the rest falls into place, because ordinary indoor air rarely delivers either. Let it dry out or shove it next to a heater and it answers fast, dropping leaflets and browning at the tips. Keep the soil evenly moist and the air humid, though, and it shrugs off almost every other slip.
It pulls its weight in a home with pets and kids, since the ASPCA lists it as non-toxic. That makes it a rare houseplant you can grow flat-out without sweating a curious nibble, and a great-looking one while it powers along.
Care
The short version: bright indirect light, soil kept evenly moist but never soggy, and humid air around 61°F to 70°F (16°C to 21°C). Feed monthly through the growing season and divide the clump every few years.
Light
Park the fern in bright, indirect light, the sweet spot near a window but clear of direct sun. It also rolls with medium light, partial shade, and even full shade, so a dim corner will not stop it, but strong sun will scorch the fronds outright.
Water
Keep the potting mix evenly moist but never soggy, easing off just a little come winter. Let it dry out and the fern fights back by shedding leaflets and browning at the tips, so nailing consistent watering matters more than anything else you do.
Soil
Pot it in a peaty, soil-based mix that drains fast yet still grips moisture, like a peat and vermiculite blend. That combo keeps the roots damp and working without ever leaving them stewing in water.
Temperature
The fern hits its stride between 61°F and 70°F (16°C to 21°C), plain old room range. Just keep it clear of cold drafts and the dry blast off radiators, since both pull moisture out of the fronds.
Humidity
This is a high-humidity plant, and dry indoor air is the one thing that knocks it back. Drive the moisture up around it by double potting or by standing the pot on a tray of wet pebbles, which runs rings around misting.
Feeding
Feed monthly from spring to early fall while the fern is charging ahead, then cut it off over winter. Reach for a weak, half-strength liquid feed or a slow-release houseplant fertilizer, because a strong dose torches the roots.
Pruning
Snip old or beat-up fronds off at the soil line to clear the deck for new growth. And if the plant has dried out and shed, cut the fronds back to about 2 inches and let it bounce back from the base.
Repotting
Divide the fern every few years in spring, once the clump has stuffed its pot. Keep an eye out for roots circling the container and crowded fronds running out of steam, both shouting that it is time to split and refresh.
Size & spacing
Indoors the fern shoots up to about 2 to 3 feet (61 to 91 cm) tall and just as wide, so give it room to arch and show off. Those spreading fronds look killer where they can drape, like a hanging basket or up on a stand.
Troubleshooting
Nearly every Boston fern hiccup traces straight back to dry air, dry soil, or a hitchhiking pest. Read the early signs on the fronds and you can jump in before the plant starts shedding for real. Spot your match below, then move on it while quick action still pays off.
Browning fronds and leaflets raining down on the floor
Catch this one early and the fix is quick, because dry air and dry soil are nearly always to blame, and the fern flags it at the leaflet tips well before it starts dropping. Soak the habit of even watering into your routine, crank up the humidity with a pebble tray or by double potting, and pull the plant clear of radiators and drafts. If it has dried right out, chop the fronds back to about 2 inches and watch it surge into fresh growth from the base.
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 studded with cottony fluff or small bumps
Spot those bumps and cottony clusters and you have found scale insects or mealybugs, with the sticky film being the honeydew they leave behind. Strip off and bin any fronds that are badly overrun, then go after the rest of the foliage. Make a quick once-over of every new plant before it joins the collection, and park an affected fern on its own until it comes up clean.
Fix:
- Remove and discard heavily infested fronds
- Treat remaining foliage for scale or mealybugs
Toxicity
Here is the part pet owners and parents love: the Boston fern is safe. The ASPCA lists it as non-toxic to cats and dogs, and no toxic compound shows up in the plant, so it sits happily within reach of curious animals and kids.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Cats get a clean pass here. The ASPCA lists Boston fern as non-toxic to them and logs no toxic principle, so a curious nibble is no trouble at all.
Dogs None
Dogs are clear too. The ASPCA names this fern non-toxic to them, so a chewed frond will not poison your dog.
Horses Safe
No toxic compound turns up in this plant, so a horse can graze a frond with zero poisoning risk.
Rabbits Safe
A rabbit can crunch the fronds and stay perfectly fine, since the fern packs nothing toxic. Plenty of fresh greens still beat fern leaves as the daily staple.
Livestock Safe
Cattle, goats, and sheep run into no toxic principle in this fern, so a mouthful off a stray plant stays safe.
Birds Safe
The fronds carry no known toxin, which makes this fern a safe splash of green to grow around birds.
People Safe
Boston fern is harmless to people, so a child who mouths a frond is fine. It is not grown as food, though, so nothing on it is worth a bite.
Varieties
A handful of named cultivars show up most often, set apart mainly by size, frond texture, and color. These are the ones worth chasing down.
'Bostoniensis'
The original Boston fern that started it all, throwing out arching fronds that stretch to about 4 feet long and 6 inches wide.
'Compacta'
A neater, smaller spin on the standard fern that slots into a tight space with ease.
'Florida Ruffle'
Packed with denser, more finely cut fronds, it delivers a soft, ruffled look that really fills out.
'Rita's Gold'
A standout grown for new foliage that flushes a bright chartreuse to golden-green.
How to propagate
Boston ferns multiply fast and easily, and the plant powers most of the job itself through dividing clumps and self-rooting runners.
DivisionEasy
Spring · A few weeks to a couple of months to root and resume growth
Dividing the clump is the fast track to a whole shelf of new ferns. Come spring, slice the root ball straight down into halves or quarters, hang onto as many fronds as you can per piece, and let the divisions root and resume growth over a few weeks to a couple of months. The fern also marches outward on its own through runners that root where they touch soil, and in the wild it fires off spores from the undersides of the fronds.
Offsets & pupsEasy
Spring to summer · Several weeks once a rooted runner is separated
The fern shoots out runners that sprout small plantlets wherever they hit moist soil. Once a runner has rooted, snip it free from the parent in spring or summer, and the new plant takes off within a few weeks.
Myths
Boston fern is poisonous to cats and dogs like so many houseplants.
Great news, this one is safe. The ASPCA lists Boston fern as non-toxic to both cats and dogs, so it grabs a spot in homes where loads of other houseplants get shut out.
Misting is the best way to give a Boston fern the humidity it craves.
Misting barely moves the humidity needle and leaves the fronds damp, which rolls out a welcome mat for foliar leaf spot. Double potting or a pebble tray pumps up humidity far more reliably, and it keeps the leaves dry into the bargain.