Most Poisonous Landscape Plants for Dogs

It’s hard to relax in a yard filled with beautiful flora if you’re worried about your curious pup taking a bite of toxic foliage.

It’s important for dog owners to research the kinds of plants they have in their backyard. Dogs are curious creatures that love to get into trouble, so pet owners need to be informed and keep their furry best friends out of harm’s way. Your pet ingesting a poisonous plant can lead to vomiting, diarrhea, and even death. 

Read on to learn more about the most common toxic landscape plants for dogs, where you might find them growing, and how to protect Fido from being poisoned. 

1. Amaryllis

Amaryllis is an easy-to-grow plant that’s a seasonal favorite for gifting during the winter holiday season. It has thick, leafless stalks and large, red, trumpet-shaped blooms. It grows outdoors in USDA zones 8 to 11, and many grow it indoors outside of these regions. 

• Toxic elements: Toxins are present in the bulb, leaves, and stem. 
• Symptoms of poisoning: Lethargy, vomiting, tremors, diarrhea, loss of appetite, and abdominal pain. 

2. Autumn crocus

Autumn crocus, also called meadow saffron or naked ladies, is a member of the lily family. Not all lilies are toxic to dogs, but autumn crocus is a variety that dog owners should be wary of. They bloom in the Midwest in September, with leaves like small green tulips or heads of romaine lettuce, and light pink-purple flowers.

• Toxic elements: Flowers, leaves, and bulbs.
• Symptoms of poisoning: Vomiting, diarrhea, bone marrow loss, and liver failure.

3. Castor bean

Castor bean (castor oil plant) is classified as a large shrub or small tree, and it can grow up to 40 feet high. The plant has large leaves and bright pink or red flowers and seed pods. Castor bean grows along river beds and roadsides in the Southwestern United States. It thrives in USDA Hardiness Zones 9 through 11. 

• Toxic elements: Castor seeds/beans contain ricin and are 6,000 times more poisonous than cyanide.
• Symptoms of poisoning: Loss of appetite, vomiting, diarrhea, excessive thirst, trembling, seizures, loss of coordination, coma, death.

4. English Ivy

English ivy, or common ivy, grows in the woods as a vine wrapping around trees, or in your yard as a ground cover. It grows quickly and is considered invasive in most regions of the United States. Symptoms of poisoning are typically mild, but excessive vomiting can require a trip to the vet and an IV. 

• Toxic elements: All parts of the plant are poisonous, especially the leaves.
• Symptoms of poisoning: Abdominal pain, vomiting, diarrhea, and hypersalivation.

5. Hydrangea

Hydrangeas are elegant shrubs that grow big, bright flowers in the spring and summer. There are many varieties of this plant, but most hydrangeas grow large clusters of small-petaled flowers, ranging in color from blue to pink, purple, and white. Hydrangeas grow naturally in the eastern U.S. and are planted across the country in hardiness zones 3 to 7. 

• Toxic elements: The flowers, buds, and leaves contain hydrangin, which breaks down into cyanide when consumed by dogs. 
• Symptoms of poisoning: Vomiting, diarrhea, depression, abdominal pain, coma, seizures, nausea, and stiffness. 

6. Japanese yews

Japanese yews, also known as Southern yew or Buddhist pine, are trees that are commonly used as hedges and range from 2.5 feet to more than 50 feet high. They produce small red berries and bright green foliage, which is popular during the holiday season. The plant is toxic to most animals and humans, but white-tailed deer enjoy munching on the plant’s foliage.

• Toxic elements: Leaves, seeds, and bark.
• Symptoms of poisoning: Lethargy, vomiting, seizures, unbalanced gait, muscle tremors, and heart and blood pressure changes.

7. Lily of the valley

Lily of the valley is a sweet-smelling woodland flower that thrives in the shade and is a favorite flower found in many bouquets. It has white bell-shaped flowers that cluster along one side of a stalk. It’s commonly found in eastern states, especially in the northeast. It is hardy to zones 3 to 9.   

• Toxic elements: The entire plant.
• Symptoms of poisoning: Heart problems, disorientation, changes in heart rate or rhythm, vomiting, low blood pressure, seizures, or coma. 

8. Nerium oleander

Oleander is an ornamental, flowering shrub that grows up to 12 feet. Flowers range from pink to white and yellow. It grows quickly and often appears around coastal southern locations, in zones 8b to 10. It contains cardiac glycosides.

• Toxic elements: The entire plant is toxic to humans and pets.
• Symptoms of poisoning: Heart problems, changes in heart rate or rhythm, diarrhea, stomach pain, excessive drooling, and death.

9. Rhododendron

Rhododendron (Azalea) is a flowering shrub that pops up in regions along the Atlantic coast. It is fragrant, with funnel-shaped flowers ranging from pink to red, yellow, and purple. 

This plant contains grayanotoxin, which is poisonous to animals. However, it would be rare for a dog to eat enough of this plant to get deathly ill.

• Toxic elements: The entire plant.
• Symptoms of poisoning: Upset stomach, weakness, tremors, low blood pressure, irregular heart rate, and irregular heart rhythm. 

10. Sago palm

The sago palm (cycads) is a popular ornamental plant, because it looks like a miniature palm tree. This plant grows indoors across the country or outdoors in warmer, tropical climates, like Florida, California, and Georgia, in planting zones 8 to 10. The toxin cycasin is found throughout the plant. 

• Toxic elements: Seeds and nuts are the most toxic elements, but the leaves and bark are poisonous, too. It’s toxic to all pets.
• Symptoms of poisoning: Vomiting, diarrhea, seizures, liver failure, and death.

11. Tulips

Tulips grow in the wild and are also included in many bouquets. Tulip flowers have a cup shape and they come in various colors. Since the bulbs are the most toxic part, you should be most concerned about your pet if you find the tulips dug out of the ground. They are winter-hardy flowers that can be grown in zones 3 to 8.

• Toxic elements: All parts of the plant. Bulbs are the most toxic, but chewing on the leaves will lead to an upset stomach.
• Symptoms of poisoning: Depression, dehydration, lethargy, loss of appetite, upset stomach, convulsions, and death. 

Other common plants that are toxic to dogs

You might not be aware of how many common plants, indoor or outdoor, are poisonous to your pets. It’s important to identify and research all plants that are in close vicinity to your pets to make sure they won’t accidentally eat them and get sick.

Some other common plants to watch out for include:

• Aloe vera
• American holly
• Apricot trees
• Baby’s Breath
• Begonia
• Calla lily
• Chrysanthemum
• Cyclamen
• Daffodil
• Deadly nightshade
• Dieffenbachia
• Elephant ears
• Foxglove
• Gladiola
• Grapevines
• Hemlock
• Hyacinth
• Jessamines
• Larkspur
• Milkweed
• Mistletoe
• Morning glory
• Narcissus 
• Ragwort
• Rhubarb
• Tomato (unripe)
• Wild cherry
• Wisteria

How to reduce the risk of toxic plants in your yard

Many toxic plants can be poisonous to other pets and even humans, so it is sometimes the best option to avoid them altogether. 

If you don’t want to get rid of your beautiful but potentially dangerous plants, you will need to be cautious and take preventative measures to keep your pets and family members safe.

To reduce the risk of your pet being poisoned by plants, be sure to:

1. Identify and label all the plants in your yard that are accessible to your dog.
2. Move toxic plants away from your pet’s reach or put them in hanging baskets.
3. Barricade larger plants with fences so they’re out of your pup’s reach.
4. Store gardening supplies and materials away from your pet’s reach.
5. Wear gloves while gardening and wash your hands carefully when you’re done.
6. Pay attention to bouquets and gifted houseplants, especially during the holiday season.
7. Keep your pet busy by playing with them or providing toys to keep them occupied. 

How to make your yard dog-friendly

We don’t always have time to take our beloved dogs for a walk or to give them our full attention while they’re outside playing in the yard. If you have a fenced yard, it’s easy to let them roam free, but some pets are good at finding trouble when unsupervised.

Bored pets can quickly become curious about toxic plants. Instead of letting boredom get the best of your furry friends, provide a fun outdoor area where they can bask in the sun and play the day away.

By keeping your dog too distracted to discover any toxic plants in your landscape, you’re helping keep them happy and out of harm’s way, and giving yourself peace of mind that your pet is safe.

How to make your yard a paradise for pups: 

• Plant dog-friendly grass
• Keep it fenced
• Create a designated dog zone
• Allow plenty of room to run
• Ensure there are shady areas for protection
• Take care of your yard to prevent fleas
• Install paths to let them play PAW Patrol and guard their territory

FAQ about poisonous plants for dogs

Too busy playing with your pup to get everything done on your to-do list? Let a Lawn Love expert lend a hand with all your lawn care and landscaping needs. 

Main Photo Credit: smerikal | Flickr | CC BY-SA 2.0