Casandra Maier- October, 2022

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We will begin with an important disclaimer.  This is by no means a comprehensive list.  There are many more landscape plants, not included in this list, that are equally toxic to cats and dogs.  This list does not cover trees, edibles, herbs, or indoor plants, all of which have potentially harmful and toxic elements.  Always contact a veterinarian, emergency animal service, or poison control if a pet closely encounters or ingests a plant.  This article serves to educate and inform from a landscaping perspective, not to eliminate or replace the advice of a qualified vet professional.  That being said, it is astounding to discover the number of plants that have the capacity to cause harm to our fuzzy friends.  Quite simply, there are more varieties than we can possibly list.  The bulbs, shrubs, vines, succulents, groundcovers, perennials, and annuals listed here are just some of the plants that should be avoided in landscapes where pets are present.  If ingested, and in some cases upon contact, these plants and their parts are known to cause a range of unwanted symptoms in dogs and cats, including digestive upset, kidney and liver problems, cardiovascular issues, skin allergies, hyperactivity, and depression.  In the worst scenario, ingestion of these plants is deadly.  No one wants their loving animal to go out this way.  Keep your companions safe with a pet-friendly landscape and avoid these plants toxic to cats and dogs.                                          

                                 

Similar Names, Commonly Toxic

The first part of this list is composed of plants that have two things in common, their names and their toxicity.  As a rule, assume that any plant with the following words in their name are toxic to both cats and dogs.  These include:

  • Yew

  • Lily

  • Holly

  • Laurel

  • Spurge

  • Hellebore

Yews have toxic needles, seeds, bark, and berries.  However, the most toxic part is the foliage, which is fatal if ingested.  Death may occur suddenly and without precursor symptoms, which include dry mouth, stomach upset, cramps, salivation, and vomiting.  Yews are fatal to both dogs and cats, and include the following varieties:

 

  • American Yew

  • Japanese Yew

  • English Yew

  • Pacific Yew

As a cat owner, steer clear of all plants with Lily in the name, as lilies are extremely toxic to cats.  Although, some varieties also pose a risk to dogs.  All parts of these plants are toxic, especially the bulbs, leaves, stems, and flowers if eaten in quantity.  Symptoms include digestive upset, nausea, vomiting, and/or dermatitis.  The following lilies are known for their toxicity:

  • Day Lilies

  • Calla Lily

  • Easter Lily

  • Peace Lily

  • Tiger Lily

  • Lilly of the Valley

  • African Lily/ Lily of the Nile (Agapanthus)

Holly is another plant toxic to both dogs and cats alike.  The leaves and berries have a lower toxicity compared to some plants, but still result in scary symptoms such as stomach upset, loss of balance, tremors, and seizures if ingested.  Stay away from all varieties, including:

  • American Holly

  • Japanese Holly

  • English Holly

  • European Holly

 

Laurels are another variety in which all parts of the plant are harmful to cats and dogs if eaten in quantity.  This includes:

 

  • Cherry Laurel

  • Mountain Laurel

  • English Laurel

 

Dogs and cats should also stay away from Spurge varieties.  The foliage, flowers, and stems are toxic, but especially the milky sap that these plants secrete.  Varieties include:

 

  • Caper Spurge

  • Cypress Spurge

All species of Hellebore are toxic to both cats and dogs.  All parts of this plant are toxic, including the leaves, flowers, stems, and roots, but especially the berries.  Symptoms present when eaten in quantity.  Plants with this name are also called:

 

  • White Hellebore

  • Lenton Rose

 

            

                      

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Pictured: Daylilies- especially toxic to cats

Bulbs are Bad

Another rule of thumb as a cat or dog owner is to assume that all bulb species are equal in toxicity.  Simply put, bulbs are bad.  The ingestion of Daffodils is particularly scary, as all parts of the bulb and plant are fatal.  With other bulbs, the roots, stalks, leaves, and flowers lead to harmful symptoms if eaten in quantity.  These include nausea, vomiting, diarrhea, skin allergies and dermatitis, as well as nervous excitement.  Keep bulbs out of the pet-friendly garden to ensure your curious companion's safety.  The following bulbs are toxic to both cats and dogs:

 

  • Daffodils/ Narcissus

  • Tulips

  • Crocus/ Autumn Crocus

  • Hyacinth

  • Amaryllis

  • Iris

  • Dahlia

  • Lilies (mentioning these again because, yep, these bulbs are bad)

         

            

                      

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Pictured: Daffodil bulbs- fatal to both dogs and cats

Shrubs

There are many shrubs commonly found in the landscape that pose a risk to our animal companions.  Toxic bark, twigs, stems, needles, foliage, flowers, and berries make most parts of these plants harmful to cats and dogs.  The most toxic shrubs of this list include Azalea, Boxwood, Oleander, and Rhododendron.  Heart failure, coma, and death result from ingestion of any of these plant's parts.  Other shrubs on this list are harmful if eaten in quantity and lead to unwanted symptoms such as skin allergies and dermatitis, severe digestive and gastrointestinal issues, kidney problems, rapid breathing, excitability, lethargy, and depression.  When creating a pet-friendly landscape, be sure to avoid the following shrubs:

 

  • Arborvitae

  • Azalea

  • Barberry

  • Boxwood

  • Buckeye

  • Daphne

  • Euonymus

  • Gaultheria/ Wintergreen

  • Hibiscus/ Rose of Sharon

  • Hydrangea

  • Inkberry

  • Juniper

  • Nandina/ Sacred Bamboo

  • Oleander

  • Pieris

  • Privet

  • Rhododendron

  • Schefflera/ Octopus Tree/ Umbrella Plant

  • Scotch Broom

  • Wax Leaf

  • Winterberry      

         

            

                      

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Pictured: Rhododendron- fatal to both dogs and cats

Vines, Succulents, & Groundcovers

With their unique climbing growth habit, vines look aesthetic against walls, fence lines, and trellises.  However, there are certain varieties to leave out when sharing the landscape with pets.  All parts of the following vines are toxic to cats and dogs, especially the foliage, flowers, seed pods, and sap.  Keep pets away from:

 

  • Clematis

  • Morning Glory/ Dwarf Morning Glory

  • Honeysuckle

  • Jasmine

  • Moonflower

  • Trumpet Vine

  • Virginia Creeper

  • Wisteria  

 

Similarly, succulents are often chosen for their tactile rubbery leaf structure and unique aesthetic value.  It's important to note that there are many indoor succulents that are toxic to cats and dogs, such as jade plants.  However, in the outdoor landscape, steer clear of the following varieties due to their toxic leaves, stems, and sap:

  • Agave

  • Cactus

  • Yucca

Groundcovers are another plant choice often utilized for their clumping, spreading growth habit over large areas.  Yet, certain groundcovers are toxic to pets due to their foliage and/or berries.  Dermatological issues and digestive upset are often the result of ingestion or close contact.  Exercise caution by keeping dogs and cats away from the following varieties:

  • Clover (Alsike, Red and White)

  • Cottoneaster

  • English Ivy

  • Vinca/ Periwinkle

 

 

            

                      

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Pictured: Clematis- toxic to dogs and cats

Perennials

With poisonous leaves, stems, flowers, seeds, roots, tubers, and unripe fruit, the following perennials should be left out of the landscape to be considered pet-friendly.  Larkspur and Ragwort are the most poisonous of the plants listed.  Even a small amount ingested is fatal to both cats and dogs.  For the other perennials in this list, all parts of the plant should be avoided as they lead to a range of negative symptoms including dermatitis, digestive injury, nausea, vomiting, rapid breathing, teeth grinding, nervousness, depression, cardiovascular issues, kidney and liver problems, loss of balance and coordination, convulsions, and paralysis.  Keep dogs and cats away from these perennial plants:

  • Asparagus Fern

  • Black-eyed Susan

  • Bleeding Heart

  • Bluebonnet

  • Buttercup

  • Chinese Lantern

  • Chrysanthemum

  • Daisy

  • Ferns

  • Foxglove

  • Geranium

  • Larkspur

  • Lupine

  • Kaianchoe

  • Mums

  • Peony

  • Primrose

  • Ragwort

  • Snapdragon

  • St. John's Wort

  • Verbena

  • Windflower/ Anemone

  • Woody Aster

  • Yarrow

   

         

            

                       

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Pictured: Ragwort- even a small amount ingested is fatal to both dogs and cats

Annuals

Planted seasonally to bring a pop of color and vibrancy to the landscape, annual plants and flowers usually make a nice addition to any outdoor space.  However, when pets are present, we must exercise caution and avoid certain plants due to their toxicity.  The following annuals are toxic to dogs and cats, leading to a range of unwanted symptoms, such as damage to the digestive tract, skin allergies, mouth burning, swelling and irritation of the tongue, anemia, goiters, and blocked airways.  Elephant Ears, also called Alocasia, are fatal to dogs and cats if ingested.  With toxic tubers, roots, seed pods, fruits, berries, leaves, stems, and shoots, keep the annuals on this list out of the landscape to ensure pet health and safety:

  • African Violet

  • Begonia

  • Bird of Paradise

  • Croton

  • Elephant Ears/ Alocasia

  • Impatiens

  • Lantana

  • Lobelia

  • Kale

  • Marigold

  • Sweet Potato Vine        

         

            

                       

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Pictured: Elephant Ears- also called Alocasia- fatal to both dogs and cats