A Boston fern is one of the easiest houseplants to keep in a home with pets. The ASPCA lists the Boston fern as non-toxic to both cats and dogs, so a nibbled frond won’t poison your pet.
That’s good news if you’ve just found a shredded frond on the floor. Boston ferns are safe for cats in the toxic sense.
Even so, I’d still keep an eye out for an upset stomach, a mislabeled plant, or chemicals on the leaves, because those are the real risks.
The ASPCA’s Answer on Boston Fern Safety
The ASPCA puts the Boston fern on its non-toxic list for cats, dogs, and horses. Its plant database files it under the older name Nephrolepis exalta bostoniensis, which is the same plant sold today as Nephrolepis exaltata ‘Bostoniensis’.
You’ll also see Boston ferns sold as “sword fern” because of their long, blade-shaped fronds.
Why Is a Boston Fern Considered Non-Toxic?
A plant lands on the non-toxic list when it has no known compounds that poison pets. Many common houseplants carry sharp calcium oxalate crystals or harsh saponins that burn the mouth or upset the gut, and the Boston fern has neither.
The Boston fern is a true fern. It grows from spores and has no flowers, seeds, or berries, which are the parts that make some fern lookalikes dangerous.
The ASPCA database covers commonly found plants, so I always match the full botanical name on the tag. If the tag says Nephrolepis exaltata, you’re fine.
Does the Same Answer Apply to Dogs?
Yes, the ASPCA rates the Boston fern as non-toxic to dogs as well. Dogs tend to leave hanging ferns alone, but puppies chew on almost anything at nose height. A hanging planter keeps the fronds out of reach entirely.
A dog that knocks over a floor pot faces bigger problems from the mess than from the fern. Wet potting mix, a heavy ceramic pot, or fertilizer granules cause more trouble than the leaves do.
What Happens if Your Cat or Dog Chews a Frond?
Most pets that chew a Boston fern have no symptoms at all. A few vomit once or have a soft stool, and that passes on its own within a day.
Why Can a Non-Toxic Plant Still Cause Vomiting?
The ASPCA notes that eating any plant material can upset a pet’s stomach. Cats and dogs are built to eat meat, and a mouthful of tough, fibrous fronds irritates the gut lining.
Some cats eat grass and leaves on purpose to bring up a hairball. If your cat throws up a wad of green fern and fur, the plant did what your cat wanted it to do.
Watch for these mild, short-lived signs after a big chewing session:
- One or two bouts of vomiting
- A little drooling
- Softer stool for a day
- Skipping one meal
What Should You Check Besides the Chewed Fronds?
Look at what else your pet could have reached. I’d check these spots right away:
- The soil: Dug-up potting mix, slow-release fertilizer pellets, or moss.
- The saucer: Standing water that may hold fertilizer salts.
- Nearby plants: A lily or asparagus fern on the same shelf is a far bigger concern.
- Broken pieces: Plastic hooks, wire, or pottery shards.
- The plant tag: Confirm the plant is a Boston fern.
When Should You Call a Veterinarian?
Call your vet if symptoms last longer than 24 hours or look worse than a simple upset stomach. Call right away if you aren’t sure what your pet ate.
Which Symptoms Need Prompt Advice?
These signs point to something beyond a nibbled fern:
- Vomiting or diarrhea that goes on past a day
- Blood in vomit or stool
- Refusing food for more than a day
- Hiding, weakness, or low energy
- Pawing at the mouth, swollen lips, or a red rash
- Trouble breathing, tremors, or seizures
Kittens, puppies, seniors, and pets with kidney or gut problems dehydrate fast. I’d call sooner for them.
You can also reach the ASPCA Animal Poison Control Center, which runs a 24-hour hotline. They charge a consultation fee.
What Plant Details Should You Have Ready?
Your vet works faster with clear facts. Gather these before you call:
- The plant tag or the full botanical name
- A clear photo of the fronds, stems, and any berries
- About how much your pet ate and when
- Any pesticide, leaf shine, or fertilizer used in the past two weeks
- Your pet’s weight, age, and health conditions
If you can, bring a small piece of the plant in a zip bag to the clinic.
Which Ferns and Fern Lookalikes Aren’t Safe?
Asparagus fern is the plant I’d worry about most. It looks like a fern, but it belongs to a different plant group, and the ASPCA lists it as toxic to cats and dogs.
Most true ferns sold as houseplants are pet-safe. Trouble comes from plants that only borrow the word “fern” and from a few wild outdoor species.
Why Is Asparagus Fern a Different Risk?
Asparagus fern is a flowering plant in the asparagus family. Stores sell it as sprengeri fern, emerald fern, lace fern, plumosa fern, or foxtail fern.
The ASPCA lists sprengeri fern as toxic. Its red berries can cause vomiting, diarrhea, and belly pain. Repeated contact with the leaves can also give pets an itchy skin rash.
The stems carry small spines, and the berries are bright and tempting. I keep asparagus fern out of any home with a pet who chews plants.
Why Should You Identify Outdoor Ferns Before Allowing Access?
Outdoor plants need a closer look because common names get messy. Poison hemlock is sometimes called “winter fern,” and it’s deadly to pets and people.
Bracken fern grows wild across much of the US. It causes serious illness in horses and cattle that graze on it over time, so I’d keep pets from snacking on it too.
Sago palm isn’t a fern at all, but people often lump it in because of its feathery leaves. It’s one of the most dangerous plants for dogs.
How Can You Tell a Boston Fern From an Asparagus Fern?
Read the botanical name first, then look at the leaves. Boston fern has flat, comb-like fronds, while asparagus fern has needle-like leaves on woody, spiny stems.
Check the Botanical Name on the Label
A Boston fern tag reads Nephrolepis exaltata, often followed by ‘Bostoniensis’ or a variety name like ‘Fluffy Ruffles’. An asparagus fern tag reads Asparagus densiflorus, Asparagus setaceus, or ‘Sprengeri’.
The common name on the pot means little. “Emerald fern” and “lace fern” both point to an asparagus plant, so trust the Latin name.
Compare the Fronds and Growth Habit
The differences are easy to spot once you know them:
| Feature | Boston fern | Asparagus fern |
|---|---|---|
| Botanical name | Nephrolepis exaltata | Asparagus densiflorus |
| Leaves | Flat leaflets in two neat rows | Fine needles in fluffy clusters |
| Stems | Soft, no spines | Woody, with small spines |
| Flowers or berries | None | Small white flowers, red berries |
| Underside | Spore dots, sometimes | No spores |
| Pet safety (ASPCA) | Non-toxic | Toxic |
Some mature fronds show rows of tiny brown dots underneath. Those are spore cases, a sign of a true fern, though Boston ferns don’t always make them.
What About Pesticides and Fertilizer on the Plant?
Chemicals cause more pet trouble with a Boston fern than the plant does. Leaf residue, fertilizer, and potting mix additives all deserve attention.
Check Recently Treated Fronds
Nurseries often treat ferns for pests before sale. I’d rinse a new fern in the shower with lukewarm water and keep it in a closed room for a week or two before pets get near it.
If you treat pests yourself, read the label for pet safety and keep animals away until the leaves are fully dry. Ferns are sensitive to oils and soaps, so test one frond first. My guide to spider mites on indoor plants covers gentler options.
Skip leaf shine products on ferns. The fronds don’t need them, and pets lick what they rub against.
Keep Pets Away From Fertilizer and Potting Mix
Boston ferns are light feeders. Half-strength balanced liquid fertilizer about once a month in spring and summer is plenty, with none in winter. My picks for the best fertilizer for ferns stick to that gentle approach.
Store fertilizer bags and bottles in a closed cabinet. Dogs love the smell of bone meal and blood meal, and fertilizer with added iron or pesticides can make them sick.
Empty the saucer after watering so pets can’t drink salty runoff. A layer of large pebbles over the soil also stops cats from digging or using the pot as a litter box.
How Can You Keep Pets From Shredding Your Fern?
A hanging basket solves most problems. Pair it with a pet-friendly plant your cat is allowed to chew, and your fern stays full.
Choose a Hanging Spot Your Pet Can’t Reach
Hang the basket at least 3 feet from any shelf, couch back, or windowsill your cat could jump from. Cats can leap 5 feet or more, so plan for their launch points.
Pick a sturdy ceiling hook rated for the wet weight of the plant. A freshly watered basket is much heavier than it looks.
Long fronds that hang low invite batting paws. Trim any fronds that dangle within reach, and turn the basket now and then for even growth. If light is limited, my list of low-light hanging plants offers other options for high spots.
Offer a Safer Outlet for Chewing and Play
Many cats chew plants out of boredom or a craving for greens. Set out a pot of cat grass, which is usually wheat, oat, or barley sprouts, in a spot your cat already likes.
Grow two pots and swap them every couple of weeks so one is always fresh. Add daily play with a wand toy, and brush long-haired cats often to cut down on hairballs.
Bitter apple spray on the pot rim helps some cats. Never use cayenne or pepper sprays, since they can burn a cat’s eyes.
Which Other Ferns Are Safer Choices for Pet Homes?
Many ferns safe for cats are easy to find at garden centers. The ASPCA lists several true ferns as non-toxic, including Boston, button, rabbit’s foot, mother, staghorn