The Most Dangerous Plants in Your Yard
Your landscape may look like a safe oasis for your kids and pets, but lurking behind those shade trees, flowers and bushy shrubs may be hidden dangers. We don't mean biting and stinging insects, either. Nearly 70,000 people are poisoned by plants every year in the U.S., and that doesn't count the thousands of pets and farm animals poisoned by vegetation too. Trees, shrubs, groundcovers, flowers and fungi can all be poisonous. Within plant groups, some species are toxic while others are pretty harmless. For example, tomatoes are in the nightshade family of plants (along with potatoes and eggplant). They seem pretty safe, but they're distant cousins to deadly nightshade (Atropa belladonna), a very toxic shrub containing tropane alkaloids.
Speaking of tomatoes, these red globes aren't nearly as friendly as they may appear. We eat the fruit, but the leaves are actually toxic and can cause severe gastrointestinal distress, diarrhea, confusion and drowsiness. Various parts of a plant that may be poisonous while others remain safe include:
Trees provide shade and shelter and add height and architectural balance to the garden. Even though they're valuable additions to the landscape that can increase the value of your property, some trees are very toxic. Many varieties have specific parts that cause problems, like their acorns or flowers. Here are some popular trees that actually have poisonous features:
- Apricot - leaves, stems and seeds
- Avocado - fruit, seeds, leaves and bark (for animals)
- Black locust tree - foliage and bark
- Black Walnut - bark and nut shells
- Cherry - The twigs and foliage of both wild and cultivated cherry trees are poisonous.
- Chinaberry - fruit and leaves
- Elderberry - both the tree and shrub are toxic
- Golden chain tree - poisonous seed pods
- Horse Chestnut - branches, leaves, seeds and flowers
- Oak - The acorns and foliage are mildly toxic and may take weeks of prolonged contact to present symptoms.
- Yew - Some yew varieties have very toxic berries and foliage.
The poisonous trees listed here are a representative but not exhaustive list. Within their ranks there may be specific cultivars that are more or less poisonous. If you want to evaluate a tree on your property (or one you wish to purchase), consider contacting your regional Cooperative Extension Office for more information. This free service is provided in conjunction with the United States Department of Agriculture to help educate the public about regional weather, soil, flora and fauna. The link will take you to an interactive map where you can drill down to your state and county for phone number and address listings: Cooperative Extension Office Finder (http://www.csrees.usda.gov/Extension/)
These tall plants probably add structure to your flowerbeds and grace the walkway to your front door, but flowering or not, landscape scrubs may be toxic when the leaves, berries, roots or seeds are touched or ingested:
- Burning Bush
- Common Privet
- Daphne Shrub (very toxic)
- American Holly
Flowering Plants and Vines
Flowering plants bring color and texture to the garden, and their ability to attract attention makes poisonous flowers that much more dangerous. These plants and vines may have poisonous flowers, stems, leaves, seeds or roots:
- Aloe vera
- American Bittersweet
- Asparagus Fern
- Autumn Crocus
- Bird of Paradise
- Calla Lily
- Castor bean - very toxic and potentially fatal when ingested
- Chinese Jade
- Day Lilies
- Easter Lily
- English ivy
- Lily of the valley
- Oleander - very toxic and potentially fatal when ingested
- Poison ivy
- Poison oak
- Poison Sumac
- Wisteria vine
Getting Help in an Emergency
If you think someone has been exposed to or ingested a toxic plant, get help immediately. Call emergency services in your area, especially if you determine the person is having trouble breathing (which can occur quickly in the case of an allergic reaction). Contact a doctor, or in the case of a pet, a veterinarian. Keep syrup of ipecac in your medicine cabinet in case you're instructed to induce vomiting. Activated charcoal is sometimes recommended too because it absorbs poisons in the stomach. Keeping some on hand is also a good idea.
For information and advice about toxic plants and other poisons, keep the National Poison Control Center (AAPCC) hotline on your list of emergency contacts. The main line will route you to the regional poison control center for your area: (800-222-1222). For pet information, contact the ASPCA's Animal Poison Control Center (888-426-4435). There is a charge for the ASPCA's hotline.
Risk Assessment: Levels of Toxicity In Common Plants
In fact, many garden favorites are in whole or in part toxic to people and pets. They may not all be potential killers, but when ingested. they can cause discomfort, irritation and even potentially life threatening allergic reactions.
Making an accurate risk assessment can be difficult, though. Some plants can be very poisonous when ingested but still seldom fatal because they taste terrible and cause burning inside the mouth. A pet or child sampling it will most likely spit it out right away. That's one reason some of the literature on common poisonous plants is confusing and even contradictory. Further, plants can contain many different poisons in potentially varying degrees across their lifecycles too.
The poisons themselves can also impact people differently. You'll sometimes see cautions about plants and plant products that are hazardous to young children, the elderly and the chronically ill. That's because these groups may be struggling with lowered resistance anyway. The lesson here is that plants are complex organisms, and to keep your landscape safe for your family, it's important to research your plant purchases carefully and educate your family about plant safety.