They're pretty, but poison. Many common indoor and outdoor plants can make pets and people ill. (2024)

A remarkable number of commonly grown plants show up on poisonous-plant lists.

Still, adult poisonings from ingesting plants are relatively rare. It's more of a concern when young children or pets are present because they are more likely to eat something they shouldn’t. Also, their relatively low body weights make them more sensitive to toxins in parts of plants.

For a plant to be considered poisonous, it does not necessarily mean that eating a small amount might kill you. Most poisonous plants fall into the category because eating them could make you sick. In most instances, substantial amounts of the plant need to be eaten for any ill effect to be observed. One of my references on poisonous plants even includes hot peppers (Capsicum annuum) because the capsaicin in the peppers causes a painful burning if eaten.

Most poisonous plants must be consumed to be toxic, but a couple of plants can cause problems if you simply come into contact with them. Poison ivy (Toxicodendron radicans) is a well-known vining plant that causes an itchy rash for those sensitive to it. Stinging nettle (Urtica dioica) shows up occasionally in area yards. It is covered with fine hairs that inflect a painful sting if you come into contact with them.

A surprising number of common indoor and outdoor ornamental plants are considered poisonous. Indoor plants such as dumb cane (Dieffenbachia), Chinese evergreen (Aglaonema), pothos ivy (Epipremnum aureum), English ivy (Hedera helix), florist azaleas (Rhododendron) and philodendrons are common in many homes.

These and other toxic indoor plants should not be used in homes with small children or should be placed where they do not have access to them. It would be better to stick to nontoxic indoor plants, like African violet (Saintpaulia), wandering Jew (Tradescantia zebrina) and spider plant (Chlorophytum).

In the landscape, popular plants such as amaryllis (Hippeastrum), azalea (Rhododendron), caladium (Caladium x hortulanum), elephant ear (Colocasia; Alocasia), irises (Iris species), lantana (Lantana camara), oleander (Nerium oleander— one of the more toxic landscape plants), milkweed (Asclepias species), wisteria (Wisteria species), Japanese yew (Podocarpus macrophyllus) and yellow jessamine (Gelsemium sempervirens) possess at least one poisonous part.

These are just a few examples. You don't necessarily need to rip these out of your landscape. But they would not be a good choice for planting around a school play yard where young children have access to them.

Some generalguidelines

Don’t leave young children unsupervised outdoors. Learn about the poisonous plants in your yard and neighborhood and keep small children away from them. Be especially careful when children are around colorful flowers, berries or mushrooms.

As soon as they can understand, teach children to never chew on or eat any part of indoor plants, plants in the landscape or wild plants. Teach children to recognize poison ivy and stay away from coming into contact with it.

Be extremely cautious if you choose to make medical preparations from plants for yourself.

What birds and other animals eat is not necessarily harmless to people. There is no safe, simple test for poisonous plants. Cooking does not always destroy the toxin.

Always store seeds and bulbs for your garden in a safe, inaccessible place where young children cannot find them. The bulbs of many plants are particularly toxic. These toxins are there to discourage animals from eating them.

Do not eat unusual parts of familiar edible plants. While the tubers of potatoes and the fruit of eggplants, tomatoes and peppers are edible, the foliage contains toxic alkaloids that might make you sick if consumed in sufficient quantities.

Most adult poisonings involve consuming wild mushrooms and medicinal plants, and most cases among children involve the very young. Common sense, caution and educating children are the best ways of preventing problems with poisonous plants.

Pets are at risk, too

Because pets cannot be taught which plants are poisonous, you must keep them away from poisonous plants, particularly those indoors. The ASPCA website provides lists of nontoxic plants for use indoors. But most pet poisonings involve human medicines rather than plants.

The most frequent plant poisoning of dogs I’ve encountered over the years involves the seeds of the commonly grown sago palm (Cycas revoluta). Female sagos produce lots of large seeds with a fleshy, reddish covering that ripen in February or March. Dogs will readily chew or eat the highly toxic seeds leading to tragic deaths. Do not allow dogs to eat these seeds.

Easter lilies (Lilium longiflorum), a common plant used indoors to decorate for Easter, are highly toxic to cats.

Information resources

In case of poisoning or suspected poisoning of a person, call your family physician immediately and be prepared to provide the name of the plant eaten. Or, take the patient along with a piece of the plant eaten to the nearest emergency room.

A nationwide poison hotline phone number may be used to reach the poison control center nearest to you at (800) 222-1222. You can find extensive information on poisonous plants on the internet using a search engine. Check the ASPCA website for plants poisonous to dogs and cats.