10 Poisonous Plants You Might Have Around Your Home and Yard
Updated: May 04, 2024
From sago palms to milkweed, there are toxic plants all around us. But they're not all monsters. Here's how to live with them safely.
What To Do if a Child or Pet Eats a Poisonous Plant
We invite plants from all over the world into our homes and gardens. But a surprising number of them are actually toxic in one way or another, including my beloved aloe vera plant. That’s because over the eons, many plants have developed chemical compounds to discourage predators from eating them.
“Bringing plants from nature to our homes and landscapes hasn’t made the plants disarm themselves,” says Justin Hancock, a horticulturist at Costa Farms. “So it’s helpful to be aware of which plants can potentially be dangerous to chewers or nibblers in your household.”
For many toxic plants, touching them doesn’t cause anything worse than skin irritation. But it’s still safer to keep them out of reach from children and pets.
If someone in your house ingests one, however, or if you think they might be having any kind of reaction from a plant, call your pediatrician, veterinarian or the Poison Control Centers (1-800-222-1222) immediately, or take them to the nearest emergency room.
“The key is to know what plant you have so the doctor can treat it correctly,” says Lisa Eldred Steinkopf, aka The Houseplant Guru. “My cats only seem to chew on the ones that aren’t toxic. But every animal is different and dogs can be particularly big chewers, especially puppies.”
When in doubt, also check this list from the American Society for the Prevention of Cruelty to Animals (ASPCA).
Here are a few toxic plants to keep an eye out for in your yard and house.
Milkweed
Many of us encourage milkweed to grow in our yards because it’s a host plant for monarch butterflies. When caterpillars eat milkweed, its toxins shield them against predators. But in humans and pets, touching milkweed plants can cause mild skin irritation, and ingesting enough of their toxins can even be fatal.
“Because it plays a vital role in the monarch’s survival, milkweed has an important place in the home landscape,” says horticulturalist Keri Wilson. “Its toxins [in most cases] do not pose much of a likely threat to humans and animals. The taste alone is an effective deterrent.”
Ultimately, milkweed is helpful for humans, too. Native Americans used it for clothing and rope fiber for more than 1,000 years, as well as for food seasoning and medicine to treat ailments from warts to stomach problems. Later, in World War II, the floss (fluffy fibers from the seed pods) was used in military life jackets to make them buoyant.
If you’re worried about milkweed’s toxicity but still want to grow it in your yard, consider planting it behind a barrier to keep kids and pets away. Be aware other plants in milkweed’s dogbane family contain dangerous alkaloids, including allamanda, desert rose, mandevilla, periwinkle and vinca.
Mistletoe
Mistletoe’s white berries and leaves are moderately poisonous to humans. The plant also attaches to trees and steals their nutrients. But mistletoe also holds an important place in the web of life.
“Mistletoe is another toxic plant that is beneficial for wildlife,” says Wilson. “Mistletoe-infested trees die early due to lack of nutrients, but these dead trees become critical habitats for nesting birds and mammals.”
Birds, including mourning doves, bluebirds, robins and evening grosbeaks, also depend on mistletoe berries for food. So you probably don’t need to remove it from your yard. Most people can also keep it on their holiday decoration list, because ingesting small amounts usually doesn’t create any negative symptoms.
But if you have children or gobbly pets, don’t hang mistletoe with berries that can fall off; some mistletoe decorations have real leaves and fake berries. And if you’re at all concerned, don’t bring it into your house.
Poison Hemlock
Unlike milkweed and mistletoe, whose ecological benefits often outweigh the dangers they pose in our gardens, poison hemlock offers no positives. If it’s growing in your yard, you should get rid of it — carefully. Wear gloves and a mask, because its potent toxins target the central nervous system.
Ingesting it can be fatal. Breathing air near freshly mowed stalks can irritate your lungs. And touching it, especially the seeds, can cause a rash.
Poison hemlock grows in every state, and it’s becoming more common in yards in some suburban areas. So be vigilant. Most serious poisonings come from people eating it after mistaking it for parsley or parsnip.
Bulb Plants
Some of the most cheery plants in our flower garden hold a toxic surprise. Many bulb plants, including tulips, daffodils and some lilies and irises, can cause skin irritation when touched, and gastric distress if eaten.
While all parts of these plants are poisonous, the greatest concentrations lie in the bulbs. Consuming large amounts can even be deadly to humans and pets. But that doesn’t mean you have to get rid of these happy spring flowers. Just wear gloves when planting and picking, and don’t mistake their bulbs for edible onions.
Squirrels, however, particularly enjoy tulip and lily bulbs. If you’re having a problem with them digging up your plantings, switch to daffodils instead, which are toxic to squirrels.
Sago Palms
Sago palms and closely related cardboard palms cheer us up with their wispy, tropical feel. But if you have kids or pets, they’re not so great. Ingesting even a small amount can have serious consequences.
Sago palms are so poisonous the ASPCA discourages people from growing them because about 50% of pet ingestion cases are fatal.
“This plant is often sold as a bonsai plant,” says Steinkopf. “All parts of it are extremely poisonous, especially the seeds. But it is a cool architectural plant that has an interesting shape. If you don’t have nibbling pets or children, it is a great plant.”
Euphorbias Crown of Thorns and Poinsettia
The white, latex sap from these plants irritates the skin and eyes, even causing blisters and temporary blindness in some cases. They can also cause an upset stomach and burning mouth if you munch on them. They aren’t considered fatal, just irritating.
“Most people think poinsettias are poisonous, and the white latex is irritating, but my cat has chewed on the leaves with no repercussions,” says Steinkopf. “That may not be true for other people’s cats.
“I also handle my euphorbias with no problems as far as them causing skin irritation, but it may affect others differently. Wearing gloves while repotting these plants may not be a bad idea.”
English Ivy and Snake Plant
“These are two other super-common houseplants that have chemical compounds that can cause nausea, vomiting and diarrhea if eaten,” says Hancock. English ivy and snake plants are considered moderately poisonous, and the sap can also cause rashes.
Outside, ornamental English ivy can also damage house walls and fences, because its roots find stability in cracks. That’s different from Boston ivy and Virginia creeper, which don’t tend to dig into structures.
But English ivy does have benefits. Some studies suggest it can remove airborne mold and fecal material from the air, so it’s still a great plant for a high shelf, especially in your bathroom.
Ficus
Ficus plants, including rubber trees and fiddle-leaf figs, also produce an irritating white sap that can cause dermatitis on your skin, and vomiting if eaten. It’s a problem for humans and pets, unless you have an animal from where the plant is native — like an elephant, tapir or ape. Those animals actually eat the leaves as part of their diets.
“These plants are the tried and true trees for the house, so people are going to continue to buy them,” says Steinkopf. “As they become large trees, most likely your pet won’t bother them. But when you trim them, the sap drips out and it is best if that doesn’t get on your floors.”
Why is that a problem? Because it can discolor you pet’s paws, Steinkopf says.
Diffenbachia and the Aroid Family
“Pretty much every houseplant in the aroid family contains tiny crystals in its cells that can cause intense irritation to the mouth and throat if consumed,” says Hancock.
The most popular varieties in this family include Alocasia, anthurium, arrowhead plant, Chinese evergreen, dieffenbachia, monstera, peace lily, philodendron, pothos and ZZ plant. But these plants are also desirable, because many have beautiful foliage and can tolerate a range of light conditions.
“If you have pets or kids, this plant is a candidate for hanging and can be kept out of their reach,” says Steinkopf.
Other common and particularly toxic houseplants to watch out for are cyclamen, amaryllis and jade. The latter is particularly bad for a cat’s kidneys.
Aloe Vera
There’s no way I’m getting rid of my aloe plant. It’s kept my skin intact through countless burn fumbles on the stove. But the yellow latex part of the interior leaves can cause stomach and intestinal problems for people, and especially pets, when ingested.
Then why is aloe touted as a health food? Consuming small quantities of aloe gel has been linked to a range of potential health benefits, and most scientists agree it’s just fine to put any part of the inside on your skin. But when eaten, the latex works as a laxative. It can also cause intestinal pain and even kidney failure, according to the Mayo Clinic.
“Still, these are the best plants for burns, so having one in the house is great,” says Steinkopf.
About the Experts
Lisa Eldred Steinkopf founded The Houseplant Guru, a website devoted to teaching people how to care for their plants. She’s also a writer, lecturer and author of Houseplants: The Complete Guide.
Justin Hancock is a horticulturist with Costa Farms. A lover of houseplants, tropicals, annuals and perennials, he has decades of experience gardening from Northern Minnesota to Miami.
Keri Wilson is a horticulturalist with a degree from Oklahoma State University. She writes about plants and plant issues for Garden Media Group.
Originally Published: February 05, 2024
