Toxic plants to watch out for

Flowering plants and leafy vines are a great way to add a pop of color and natural beauty to your indoor and outdoor space. But there’s one thing to consider when deciding what to plant: some plants and flowers are toxic.  There are plants that contain toxins which are harmful—and potentially even fatal—to both humans and animals.

While there are blooms that have vibrant hues, unique petals, and delightful scents, don’t let that fool you—these plants may still be toxic. Similarly, there are festive plants that have become holiday staples that, although they are only mildly toxic, should be handled with extra care.
A comprehensive list of poisonous plants and flowers from Good Housekeeping Magazine includes a host of plants, while varying in their level of toxicity, can cause everything from severe skin irritation to digestive and respiratory issues. Whether you’re looking for low-maintenance houseplants or want to create an enchanting garden, this list can help you know what to plant and what to avoid.

Hyacinth – There’s so much to love about hyacinths, from their bright colors to their delightful scent. While beautiful, the flowers contain calcium oxalate crystals and narcissus-like alkaloids, making them toxic to both humans and animals like cats and dogs. They can cause everything from skin irritation to severe digestive issues.

Poison Ivy – As its name suggests, poison ivy is a poisonous plant. It contains a sap called urushiol that irritates the skin upon contact, causing blisters and an itchy rash. Poison ivy is easily recognizable, thanks to its three-leaf clusters. You definitely want to stay away from this one! 

Clematis – Both the flowers and leaves on a clematis plant are poisonous to humans and animals. They contain a toxic agent called protoanemonin that can lead to mouth ulcers, irritation, and digestive issues when the plant is consumed. Additionally, touching the plant can cause skin irritation, so make sure you’re wearing gloves whenever you prune or plant clematis.

Morning Glory – You can instantly recognize a morning glory’s trumpet-shaped blooms. While the popular vining plant’s flowers aren’t toxic, the seeds are. In fact, the seeds contain chemical compounds that make them similar to LSD. They are toxic for humans and pets, and eating them can cause hallucinations, dizziness, numbness, and digestive issues.

Amaryllis – Typically purchased during the holidays, amaryllis is a festive plant that happens to be toxic. Keep the plant away from children and pets, as it contains licoryne and other toxic alkaloids that can lead to vomiting, diarrhea, and abdominal pain. While the whole plant is poisonous, the bulb has the highest concentration of toxins.

Virginia Creeper – Although not quite as poisonous as oison ivy, Virginia Creeper can still be harmful. It can cause skin irritation, blisters, and a rash when touched, and lead to digestive issues and abdominal pain when ingested. In addition to the leaves being poisonous, the berries are also toxic as they (and the sap) contain oxalate crystals.

Iris – This common garden beauty is known to be harmful to humans and pets. Keep in mind that coming in contact with its roots and leaves can irritate the skin, so it’s best to wear long sleeves and gloves if you’re going to be handling it.

Lupine – This perennial, which is a member of the pea family and can be found across the U.S., might boast visual appeal, but it contains alkaloid chemicals, which can cause harm to humans and animals. If ingested, parts of the lupine can cause upset stomach, difficulty breathing, and even seizures.

Angel Trumpet – This warm-weather plant is great for beautifying the landscape, but beware-it’s part of the nightshade family! The entire plant—from the seeds to the flowers–is toxic and harmful to humans and animals.

Autumn Crocus – This spring perennial may be easy to care for, but every part of the plant is highly toxic to humans and pets. Poisoning symptoms range from diarrhea to burning in the mouth.

Jimson Weed – With green leaves—that are sometimes tinged with purple—jimson weed is incredibly unsafe when ingested or inhaled. Although used to treat asthma and other health conditions, it can lead to nausea, vomiting, and hallucinations.

Lantana (Lantana camara) – Keep these colorful plants away from your children. Although toddlers and babies may find them attractive, they’re toxic and poisonous (even to dogs and cats).

I hope this information is useful to you as you plan your landscape and strive to work safely in your flower beds and gardens. More next week.

Tim Lewis is a Georgia Green Industry Association Certified Plant Professional, gardening writer, and former Perry High School horticulture instructor. He can be reached at (478)954-1507 or timlewis1@windstream.net.