Ghouls and Goblins won’t kill you. But these plants could.
Many of the garden plants we grow for ornamental reasons got their vibrant, exotic colors as nature’s way of saying “Warning—Poison!” While most of these are innocuous enough sitting in pots or in the garden, if ingested they could cause illness of varying severity, and sometimes even death.
World’s Deadliest Garden
The Poison Garden at the Alnwick Castle in Northumberland County, England is well-known for displaying toxic varieties in their themed “Poison Garden”. They seem to take a sadistic relish in recounting all the painful and gruesome ways you could die if you were foolhardy enough take a nibble of their Foxglove, Belladonna, Laburnum, Nightshade, Hemolock, Monkshood, or other deadly species.
From their website:
“Nux vomica‘s Latin name implies much, but it perhaps rings more bells as strychnine. Interestingly, hemlock, a poison in its own right, can be used as an antidote to Strychnine, but don’t tell Socrates, who was sent to his death with a cup of hemlock.
Those of a certain age will be familiar with Castor Oil, which is made from the plant Ricinus communis, but a single seed from the same plant will kill an adult in the most horrible way. Ricin causes nausea, severe vomiting, convulsions and subsequent disintegration of the kidneys, liver and spleen…”
Those tour guides are sick puppies, if you ask me. 😉
Yet behind the macabre presentation, the Poison Garden offers quite a bit of useful information. It is important to know which garden plants are toxic. Even common plants like Iris or Lily can be dangerous if ingested. Since most gardeners don’t take random bites from their ornamentals, we aren’t at risk as much as our pets and young ones might be. So here is a list of common garden plants that are poisonous to pets and/or humans, color-coded by danger level:
Other plants with parts that could make your pets sick include:
Aloe Vera (Just the plant’s skin), Amaryllis (Bulbs), Autumn Crocus, Bleeding Heart (Leaves and Roots), Chinese Lantern, Chrysanthemum, Daffodil (Bulbs), Flamingo Flower, Foxglove (Leaves), Helleborus (Roots), Holly (Leaves and Berries), Hyacinth, Hydrangea (Buds), Jack-in-the-Pulpit, Larkspur, Cala Lily, Peace Lily, Lily-of the-valley (Berries), Poinsettia, Rhubarb (Leaves), Sago Palm, Water Hemlock, and Wisteria (Seeds and Pods).
How Plant Toxins Affect Us
Many of these plants are toxic for the same reason: calcium oxalate crystals. These crystals get stuck in the soft tissues of the mouth, causing irritation, swelling, and drooling. This usually puffs up the lips and tongue, and in severe cases can cause death if the tongue closes the airway.
Notable (and dangerous) exceptions are plants like Water Hemlock and Oleander that affect the heart directly. Oleander is probably the most deadly one on the list. Even a single leaf can cause death in humans or animals. That’s why Oleander and other potentially fatal plants are rarely sold anymore.
Most toxic plants are only really harmful if ingested, but some exceptions (like Sago Palm or Euphorbia) can irritate your skin just from touch, and some (like the Laurel plant) can be harmful if you just breathe in their fumes!
Plant Safety Tips
If you want to enjoy the beauty of these plants without accidentally harming your kids or pets, here are some tips for keeping safe:
- Set plants on high shelves to keep them out of reach.
- Use only nontoxic fertilizer to keep them healthy (organic fertilizers are generally nontoxic).
- Keep all the toxic plants outside and out of reach of your pets.
- Teach your kids from an early age not to put any plants in their mouths.
- Deter cats from plants by spraying your plants with bitter spray, sprinkling the leaves with cayenne pepper, or sprinkling coffee grounds or orange peels on the surface of the soil. Cats can also be distracted by offering up a sacrificial plant that they would rather eat, like Cat Grass.
- Create a pet first-aid kit including a turkey baster, something to induce vomiting, and activated charcoal to help absorb toxins.
- Have one or more of these animal poison control hotline numbers handy just in case.
If you are still feeling antsy about ever touching a trowel again, here’s some context to put things in perspective: In 2014, of all the pet poisoning cases reported to the ASPCA, about 40% were the results of pets getting into medicines of some kind, 14% were the results of pets getting into household chemicals (including rodenticides, pesticides, and herbicides), 14% were a result of pets eating chocolate or other human foods, and only 5% of its cases were a result of pets eating toxic plants.
Note: I’m not a doctor. All I’ve done is read some articles on the internet and then presented you the consensus I found. I’ve done my best to be accurate, but of course you should always consult a real doctor (or veterinarian, as the case may be) if you suspect plant poisoning.