Pretty, Deadly: 8 Toxic Plants Commonly Grown in Midwest Gardens

We love summer. Summer means playing outdoors with kids, pets and loved ones. And summer also means we’re in and around the plants that grow outdoors. So we should be aware that many of the most common ornamental flowers and shrubs growing locally are also toxic plants.

The Illinois Department of Natural Resources offers a guide to the toxic plants growing in the Midwest

The Illinois Department of Natural Resources offers a guide to the poisonous plants growing in the Midwest.

In order to help you identify these plants, here is a pictorial guide to 8 of the toxic plants most commonly found on landscapes in the Midwest.

Note: This is not a comprehensive list. You can find more information about toxic plants growing in the Midwest at the Illinois Poison Center  website. 


toxic plants



Oleander (Nerium oleander) is an evergreen shrub or small tree. Home gardeners love oleander for its showy, funnel-shaped blooms. Plus, oleanders are fast-growing and easy to care for. Consequently, this makes them an appealing landscape plant. However, all parts of these toxic plants are highly poisonous. In fact, horticulturalists in some locations consider oleander to be invasive.

In fact, Oleander is one of the most toxic, commonly grown garden plants in the world. Also, ingesting any part of this plant can be deadly, especially for children. Even smoke from burning oleander can be fatal.


toxic plants

European Yew

European Yew:

The European yew (taxus baccata) is another of the very common but toxic plants grown locally. European yews are not native to the Midwest. Landscapers prize yews as formal hedges and topiary. Yews have dense, dark green, mature foliage, and are tolerant of even very severe pruning. Yews also grow relatively slowly which makes them low-maintenance. In fact, you only need to clip most yews once per year (in late summer).

All parts of a yew plant are toxic to humans with the exception of the yew berries (however, their seeds are toxic). Yews can also trigger asthma. The yew contains pollen granules that are extremely small. This pollen can easily pass through window screens. The foliage itself remains toxic even when wilted, and toxicity increases in potency when dried.


toxic plants



Larkspur (delphinium) looks beautiful, but is another of the highly toxic plants popular in Midwest landscapes.  Gardeners love larkspur for its dramatic spikes of showy blue. Larkspur has become a highly popular ornamental plant. But larkspur is packed full of potent toxins called alkaloids. For instance, if you touch the flowers, even briefly, your skin can become irritated. Larkspur can prove fatal if you eat it. Furthermore, larkspur’s seeds and young plants of are toxic to both people and animals. As the plant ages, it becomes less toxic.


toxic plants



Daffodils (narcissus) are an extremely popular plant in Midwest landscapes. However, all parts of the daffodil are toxic. Daffodils cause nausea, vomiting, diarrhea, and abdominal pain when swallowed. Daffodils grow from bulbs that could be mistaken for an edible food, like an onion. But, if you eat the bulb, you will experience severe irritation of the mouth and stomach upset. These symptoms are usually not life threatening and resolve within a few hours.


toxic plants

Angel’s Trumpet

Angel’s Trumpet:

Angel’s trumpets (brugmansia) are woody-stemmed bushes with pendulous flowers that hang like bells. People prize angel’s trumpet as decorative additions to the garden because of their elegant flowers. Unfortunately, all parts of these toxic plants contain dangerous levels of poison and may be fatal if ingested by humans or animals.


toxic plants



The seeds, stems, flowers and leaves of the foxglove plant are poisonous. They contain digitalis glycosides, which are organic compounds that act on the heart. These compounds cause an irregular heartbeat when the someone eats foxglove plants or flowers. Symptoms can also include digestive issues, headache, blurred vision and confusion and can eventually lead to death.

toxic plants

White Snakeroot

White Snakeroot:

White snakeroot (ageratina altissima) contains the toxin tremetol, which can be poisonous if consumed directly or second-hand. In addition, when cattle graze on snakeroot, the animals’ beef and milk become contaminated with the toxin. So when people ingest those substances it leads to a condition called milk sickness. Abraham Lincoln’s mother, reportedly died after swallowing snakeroot-contaminated milk.


toxic plants



Monkshood (aconitum) plants are extremely poisonous. As a result, gardeners should deal with them carefully. Monkshood was one of the first perennials grown as a garden ornamental despite being highly toxic plants. Because of their showy bright blue or yellow flowers, monkshood remains popular in Midwest gardens  Also, they thrive in garden soils, and will grow in the shade of trees. But all parts of monkshood are poisonous, especially the roots and seeds. And the flowers are deadly if eaten. Also, human skin easily absorbs the toxin. And poisoning may occur just picking the leaves without wearing gloves.

toxic plants

Toxic plants are some of the most common growing in Illinois.

Illinois Poison Center: 1-800-222-1222

For more information about toxic plants growing in the Midwest, call the Illinois Poison Center. The IPC is a non-profit health service. The IPC provides the people of Illinois with access to comprehensive information and treatment advice on potentially harmful substances. The IPC runs a free, confidential 24-hour helpline at (800) 222-1222. The helpline is staffed by specially trained medical experts, including physicians, nurses and pharmacists.

, , , , , , , , , , , , , , , , ,

One Response to Pretty, Deadly: 8 Toxic Plants Commonly Grown in Midwest Gardens

  1. Jimmy Rey May 2, 2017 at 7:22 am #

    Great post and very well explained. I really appreciate the insight here in this post and confident it’s going to be helpful to me and many others. Thanks for your post.

Leave a Reply

Call Now Button