15 Toxic Plants You May Already Have at Home

When it comes to houseplants, sometimes the beautiful can be itchy—or deadly.

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Danger in plain sight

Houseplants are a great way to spruce up your living environment. The best indoor plants look gorgeous, of course, but they can also give you a mental and physical boost, cleaning the air and reducing stress levels. But before you start exploring the health benefits of gardening and searching for the best low-maintenance plants, you need to be aware of one very important thing: Poisonous plants may be on your to-buy list—or already in your own home.

More than 700 plants are poisonous to cats and dogs, and some plants are also toxic to humans. While you might not be nibbling on your houseplants, remember that this is a concern if you have small children who live with you or who visit. Also, some plants can cause itchiness if you touch them, so you’ll want to proceed with caution, regardless. Read on for the dangerous plants you might not suspect are as toxic as they actually are.

Toxic Plants infographicGrace Luxton/rd.com, Getty Images

Aloe Vera (Aloe barbadensis miller)

This succulent plant is a favorite to have around the house because it can help soothe human skin that’s been sunburned, frostbitten, or that is prone to psoriasis, according to Penn Medicine. That’s because it contains anti-inflammatory chemical compounds called anthraquinones. However, those same compounds act as purgatives that increase mucous and water in the colon, making them moderately toxic to dogs, cats, and horses, reports the ASPCA. If your pet ingests aloe, it could lead to vomiting, lethargy, and diarrhea. Speaking of ingestion, here are the foods you shouldn’t share with your pup.

Elephant’s Ear (Alocasia)

This plant is easy to care for indoors or out, but you’ll want to keep it far from kids and pets. It contains insoluble calcium oxalates, “needle-shaped crystals [that] can irritate the skin, mouth, tongue, and throat, resulting in throat swelling, breathing difficulties, burning pain, and stomach upset,” according to the University of California. And it doesn’t have to be ingested to cause a problem: It can also cause rashes if its juice gets on the skin. That means a trip to the vet—look out for drooling, pawing at the face, and vomiting—or a call to poison control. Whether elephant’s ear is in your backyard or not, here’s how to keep dogs out of your flower beds.

Asparagus Fern (Asparagus densiflorus)

Sure, this lacy-looking fern is a beauty to behold. But it’s also a mild toxin to your pets, who might not be able to resist giving it a chomp if its fronds are dangling within reach. It contains sapogenins, chemicals that protect plants against hostile invading organisms, and in your pet, they act as a mild toxin on the skin and may cause itching and rashes. Their berries, if ingested, can cause vomiting, diarrhea, and abdominal pain.

Philodendron (Philodendron bipinnatifidum)

Meet another easy-peasy houseplant with a nasty bite. Just like elephant ears, all varieties of philodendron contain insoluble calcium oxalates that penetrate your animals’ bodily tissues—namely, in the mouth, where chewing of the leaves happens—and cause irritation of the mouth and gastrointestinal tract. In very rare cases, it might lead to obstructed breathing. Hypersalivation, vomiting, and possible swelling of the pharynx are common symptoms; treatment includes milk or water to rinse out the mouth.

Amaryllis (Amaryllis belladonna)

Every part of this gorgeous winter holiday flowering plant is toxic to humans and pets—mostly the bulb, but also the stems and leaves. It contains lycorine and other phenanthridine alkaloids, which can cause vomiting and diarrhea if ingested (by pets or humans), as well as blood pressure drops and respiratory depression in pets. Its juice can also cause some pretty serious rashes.

Sago Palm (Cycas revoluta)

Things get a little more serious for pets when it comes to sago palms and plants related to them. They contain three toxins, including, most significantly, cycasin, which can lead to liver failure in dogs, as well as seizures and tremors. How can you tell if your pet has ingested this dangerous plant? Signs will include vomiting, diarrhea, lethargy, abnormal fluid accumulation in the abdomen, abdominal pain, and black, tar-like stool. The seeds have the highest concentration of cycasin, but you shouldn’t let your pup eat any part of a palm—and if he does, he’s likely looking at some extensive treatments at the vet’s office, and a 30 percent mortality rate. Needless to say, this is one plant you don’t want to mess with. If all of this has you worried, you may want to opt for these artificial plants that no one will be able to tell are fake.

Lilies (Lillium)

It’s unlikely that you’re growing lilies as houseplants, but cat lovers beware: If you’ve brought in a bouquet filled with any members of this family—including Easter lilies, tiger lilies, or even day lilies of the Hemerocallis genus—it’s an acute danger to your fluffy feline friend. Scientists aren’t quite sure what makes lilies poisonous to cats. What they do know is that whatever it is, it can lead to renal failure, which, if not treated quickly, can lead to death. Even the nibble of one petal or a sip from the water the flowers sat in is enough to set things off. An initial period of vomiting and diarrhea may quickly subside, but the real trouble begins after 24 hours, which is why immediate care should be sought.

Mistletoe (Phoradendron)

Another plant you’re unlikely to be growing at home but perhaps might be compelled to bring in at holiday time, this one is a serious danger not only to cats but also to dogs and humans. Mistletoe berries contain polysaccharides, alkaloids, and lectins, which can give your pets gastrointestinal distress when eaten in small quantities, and seizures or even death when consumed in larger amounts. It can also cause digestive issues in humans, as well as hallucinations and skin rashes if the berry juice gets on the skin. While we’re on the subject, poinsettias are another Christmas flower that’s also poisonous to pets.

Spider Plant (Chlorophytum comosum)

As Farmers’ Almanac rightly points out, “cats are wildly attracted to spider plants (all those wiggly legs!)” And although these plants are not considered to be much of a threat to felines, or anyone, they do contain chemical compounds that may or may not be related to opium and might give your cat pal an upset stomach. Keep those spider plants high enough off the ground that even your most acrobatic feline can’t reach them. These plants are practically invincible, so don’t worry too much about hanging them up.

Oleander (Nerium oleander)

While oleander isn’t usually grown indoors, lots of folks pot these delicate shrubs and bring them in from the garden to overwinter in cold climates. And while they may look gorgeous, they are deadly. As with other plants that contain cardiac glycosides—including foxglove and lily of the valley—these compounds get rapidly absorbed by the gastrointestinal tract and quickly begin to interfere with the heart’s electrolyte balance. For pets and humans alike, this can lead to abnormal heartbeat, life-threatening potassium spikes, seizures, and even sudden death. All parts of the plant are poisonous, even in very small amounts. The good news is that they’re pretty bitter, so that should discourage even the most taste-testy members of your household.

Flowers with Bulbs

Daffodils, hyacinths, and tulips are flowers that grow from bulbs rather than seeds, and it’s these bulbs that can cause some pretty serious gastrointestinal distress if consumed in both pets and humans. We’re talking stomachaches, nausea, vomiting, and even hemorrhagic gastroenteritis. This is all thanks to lycorine, “an alkaloid with strong emetic properties (something that triggers vomiting),” according to the Pet Poison Helpline. Lycorine crystals are found in the outer layer of the bulbs, although eating the stems and leaves is also ill-advised. Additionally, Salon reports that eating bulbs can lead to blood pressure spikes, irregular heartbeat, tremors, and possibly death.

Peace Lily (Araceae)

Although it’s unrelated to true (and truly toxic) lilies, the peace lily has its own potent powers. With its insoluble calcium oxalates, it can cause unpleasant burning and swelling of the lips and tongue—in humans and pets—as well as nausea and diarrhea. It does not, however, cause kidney failure in cats, as has been reported. Another plant to stash way up high!

Rubber Tree (Ficus elastica)

These common household trees contain a sap (ficin) that can irritate the mouth, throat, and skin. Were you to be so foolhardy as to ingest some of this sap yourself, you might also find yourself with impaired coordination. In your pets, look for signs of decreased appetite, drooling, vomiting, and diarrhea. Make sure you do your research before you buy any seeds online.

Geranium (Pelargonium)

Geraniums are easy to care for and filled with lovely blossoms. But they also contain chemicals called geraniol and linalool, which will make your cats and dogs feel pretty gross: itchy on their skin if they get these compounds under their fur, nauseous, and, over time, anorexic.

Jade plant (Crassula argentea)

Another mystery of the toxic plant world is the jade. Here again, no one is quite scientifically sure why this beautiful succulent, considered by some to be good luck, will make your cat or dog vomit, or irritate their skin. On the plus side, it is, at least, considered a minor toxin. Next, find out where to buy plants online that are safe for everyone in your household.


Reader's Digest
Originally Published on Reader's Digest

Lela Nargi
I am a veteran journalist covering food & food policy, science, sustainability, books, and parenting for a wide variety of outlets including NPR, Civil Eats, Sierra, and Publishers Weekly.