Unfortunately (and unbeknownst to some), there are certain plants in your backyard that might harm you. We’re not talking about the obvious ones, either, like unwelcome intruders such as poison ivy or poison oak, but ornamentals that were planted by yourself or the previous owners.
Plants can be toxic to humans, or pets, or both. A plant may be poisonous or toxic when touched or ingested, sometimes leading to severe illness and death. The concentration of the toxin can be mainly in the roots, leaves, flowers, or fruit, or the entire plant might be toxic.
Which protective measures you should take depends on who’s accessing your backyard and many of these measures can be temporary. If you have a beautiful hedgerow of rhododendron or azaleas, by no means should you dig them all up because they’re toxic to dogs and cats. For a puppy that notoriously chews on everything within reach, put up a barrier or a netting just like you would fend off unwanted visitors from a blueberry bush. Put the plant out of reach until your pup passes the chewing stage of puppyhood.
Some plants such as belladonna, on the other hand, are so inherently toxic that they have no business whatsoever being in a backyard in the first place. Belladonna is a threat to all small kids, including the neighbor’s kids who could venture into your yard. When planting something new, always do your research about the potential toxicity of the plant. If the alarm bell goes off, you can always find a non-toxic alternative
Here are a few popular garden plants that are toxic to humans and pets. If possible, non-toxic alternatives are suggested, but the alternatives always depend on the zone where you live. Check what the local nurseries are offering, which is always a reliable indicator of which plants will do well in your climate. And if you want to do your share for biodiversity, plant a native.
All parts of hydrangeas, rhododendrons, oleander, and angel’s trumpet are toxic to humans and pets. Choose viburnum instead of hydrangea, common lilac instead of rhododendron, and Arizona rosewood instead of oleander.
All parts of the wisteria, especially the seeds, are toxic to humans and pets, A good alternative is honeysuckle. If possible, choose a native honeysuckle variety.
Yews are highly poisonous evergreens that pose a deadly danger to humans and animals if ingested. Common juniper and Eastern red cedar are suitable hardy alternatives.
The acorns that your oak tree is dropping in the fall are actually so high in tannins that they can make your dog sick, and in extreme cases, can lead to kidney failure and death. However, acorns are hard and sharp, so the likelihood of your dog eating them in large amounts is low. Meanwhile, the wildlife value of a native oak tree is very high and its benefits by far outweigh this minor risk. If you’re worried, just scoop up the acorns and dispose of them in your compost.
Two toxic perennial spring-flowering plants are lily-of-the-valley and daffodils, and both are toxic to humans and pets. An alternative to lily-of-the-valley is Virginia spiderwort, and instead of daffodils, plant spring crocuses. Avoid fall crocuses, though, which are highly toxic.
You might be surprised that the leaves of your favorite pie plant, rhubarb, contain such a high concentration of oxalic acid that they are mildly toxic to humans and pets. Since rhubarb is a compact plant, protecting it with a net is an easy way to keep away potential eaters.
English ivy is not only a groundcover that is toxic to humans and pets in all its parts, it is also invasive and grows out of control. Therefore getting rid of it once and for all is a good idea. Consider replacing it with a native alternative such as barren strawberry whose fruit are not toxic but also not edible, they’re just ornamental.
All parts of lantana, which is grown as an annual in colder climates, are toxic for humans and pets. Tall verbena is a non-toxic alternative.
Larkspur is a cottage garden favorite that is toxic to humans and pets. A safe alternative, which is native to boot, is bell flower (Campanula).
The seeds of the popular annual vine morning glory are toxic to humans and pets. The vine can also become invasive in a flower bed because it freely reseeds itself. For these two reasons, you might be better off not planting morning glory in your yard.
All parts of the foxglove are toxic to humans and pets. If you want a similar-looking alternative, hollyhock might be an alternative—with a word of caution though. While hollyhock is not toxic upon ingestion, it can cause skin reactions to humans and pets.
In addition to the ones listed above, there are numerous other common toxic garden plants. A comprehensive list of safe and poisonous garden plants can be found here. Also, for pets, the American Society for the Prevention of Cruelty to Animals maintains a list of toxic plants that you can filter by toxicity for dogs or cats.