The Homeowners Column

The Homeowners Column

Poisonous Plants in the House and Garden

Photo of Sandra Mason

Sandra Mason
State Master Gardener Coordinator

Poison hemlock, poison ivy, and poison oak are a few plants whose common names imply their inherent danger. However, many poisonous plants have lovely names like lily-of-the-valley and mayapple. Some common house and garden plants are poisonous if ingested or may cause skin reactions. Does this mean we need to rip out anything even remotely poisonous? The leaves and vines of tomatoes are listed as poisonous even though we relish the fruit. First, evaluate the risk. How poisonous is the plant and what is the likelihood of someone or something eating the plant. Here are a few suggestions to keep you and your family safe.

Be especially careful with plant selections if you have children, young dogs or cats that tend to chew. Their small body weight puts them at greater risk of poisoning as well as their tendency to eat anything that doesn't move too fast. Berries can be especially attractive to children. Teach children not to eat plants in the yard unless they have adult supervision.

Identify the plants around your yard and in your house. Check out identification books in the library. Or bring samples to your local Extension office.

Grazing through the garden is not the time to be adventuresome. Just because animals eat a particular plant does not mean it is safe for people to eat it. Although a few people I know remind me of squirrels, human physiology is different from the common grazers in the backyard.

Don't assume cooking will destroy the toxins or that a tea is dilute enough to be safe.

Be careful of look-alike plants. Comfrey leaves often used in teas look very similar to foxglove leaves, known to contain chemicals that affect the heart.

When a poisonous plant is consumed, obtain a sample plant. Estimate the quantity eaten, estimate times, duration of exposure and onset of symptoms. Contact a physician or veterinarian immediately.

Keep emergency telephone numbers handy. For human poisoning questions call the Illinois Poison Center at 1-800-942-5969. For animals, call the National Animal Poison Control at 1-800-548-2423. There is a charge for this service.

A short list of poisonous plants:


  • Amaryllis sp.
  • Dumbcane, Dieffenbachia sp.
  • English Ivy, Hedera helix
  • Oleander, Nerium oleander
  • Philodendron, Philodendron sp. (Listed as the most frequently ingested plant by the American Association of Poison Control Centers.)
  • Pothos, Scindapsus aureus
  • Schefflera sp.
  • Snake plant, Sanseviera trifasciata

Garden and landscape plants

  • Autumn crocus, Colchicum autumnale
  • Caladium spp.
  • Castor bean, Ricinus communis (Seeds are particularly toxic.)
  • Daffodil, Narcissus sp.
  • Lily-of-the-valley, Convallaria majalis
  • Lobelia, Lobelia spp.
  • Monkshood, Aconitum sp.
  • Privet, Ligustrum sp.
  • Rhododendron and azalea, Rhododendron spp.
  • Virginia creeper, Parthenocissus quinquefolia
  • Yew, Taxus sp.


  • Jimsonweed, Datura stromonium. There are some new ornamental plant introductions, often called Angel's Trumpet (Datura spp. and Brugmansia spp.), which are closely related and are also poisonous.
  • Pokeweed, Phytolacca americana. The berries are ripening now and can be attractive to children.

For a more complete listing of poisonous plants, check out the following website or contact our office at 333-7672 for a more extensive list.

The University of Illinois has an educational poisonous plant garden maintained by the College of Veterinary Medicine. It is located on St Mary's road just northwest of the Veterinary Medicine Building on South Lincoln Avenue in Urbana. The gardens include over ninety species of plants native to Illinois or commonly used as ornamentals that are potentially hazardous to animals and people. Plants are labeled, and the garden includes a thorough brochure of plants, their toxic chemicals, and symptoms of exposure or ingestion.

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