November 21, 2023

As pet parents, we often focus on indoor items such as toxic foods or household chemicals that can be harmful to our dogs. But just as important is being aware of the dangers that lie outside too. 

Lots of outdoor plants can be harmful and sometimes even fatal to dogs when eaten. Below is a list of harmful outdoor plants to avoid and tips on how to best keep your dog safe from them. 

For a full list of poisonous plants to dogs, check outRover’s extensive list.




First on the list of harmful plants for dogs are azaleas and rhododendrons. These plants are toxic to dogs because they contain the compound grayanotoxin. This toxin disrupts the sodium channels in your dog’s body causing vomiting,  diarrhea, weakness, and cardiovascular issues. 

If you have species of azaleas or rhododendrons in your garden, it's best to keep them in an off-limits space, away from your dog. Your dog ingesting as little as 0.2% of their body weight can result in poisoning. 



If you live in hot or tropical areas, then you should keep an eye out for sago palms. These palms are highly poisonous to dogs (and humans). All parts of the plant, including the seeds (nuts) contain the toxin cycasin. 

Cycasin, when ingested, can cause severe liver damage and in worst cases, neurologic issues due to the central nervous system being affected. If you suspect your dog has ingested any part of a sago palm, it's important to take them to the vet immediately. Even with veterinary intervention, the survival rate is about 50%.



Many varieties of lilies, including Easter lilies, tiger lilies, and daylilies, are toxic to dogs and can cause acute kidney damage. Eating small amounts of any part of the plant can be extremely dangerous to dogs.

Common symptoms of poisoning from lilies include:

  • Vomiting
  • Kidney failure
  • Anorexia



Oleander is an outdoor shrub most commonly found in warmer climates. All parts of the oleander plant are toxic to dogs, including its leaves and pink/white flowers. The shrub contains cardiac glycoside toxins, which affect the heart by interfering with the electrolyte balance within the muscle. 

By eating parts of the oleander shrub, your dog can suffer from irregular heart rate and rhythm, vomiting, and seizures. It's important to keep your dog away from this shrub and call your vet or ring the Pet Poison Helpline if you think they have consumed any of it.



The castor bean plant contains ricin, a highly toxic substance that is found in the plant’s leaves and seeds. Ricin is a glycoprotein that prevents proteins from being made in the body. 

Only a small amount of ricin needs to be ingested for it to be fatal to dogs. Ingesting even a few seeds can lead to vomiting, abdominal pain, bloody diarrhea, and collapse. Be sure to steer clear of castor bean plants when out on a dog walk. 



While not technically a plant, wild mushrooms can also pose a threat to dogs. The same mushrooms which are toxic to humans are also toxic to dogs. If your dog eats any wild mushrooms, it’s best to treat them as toxic and call your vet for help. 

The Death Cap mushroom is commonly found along the West Coast of America and can be fatal to dogs who eat them. It’s a good idea to remove any wild mushrooms growing in your garden to reduce the risk of your dog eating poisonous ones. 



Known for its bright yellow petals and popularity in spring, daffodils are next on the list of harmful plants for dogs. Daffodils contain a toxic alkaloid called lycorine that can cause vomiting, diarrhea, abdominal pain, and abnormal breathing when eaten by dogs. 

Both the bulb and flower can cause poisoning when eaten, so it’s best to plant daffodil bulbs out of your dog's reach and keep an eye on them when they are blooming.



Irises are a visually striking addition to any garden due to their bright and colorful flowers. However, they can be harmful to dogs when touched or ingested. Irises contain irisin, a toxin that can cause skin irritation, gastrointestinal upset, and lethargy in dogs.


9. YEW

Yew plants are commonly used to make holiday wreaths due to their dense foliage. However, yew plants are extremely poisonous to dogs. Yew plants, including English Yew and Japanese Yew, contain a toxin called taxine. 

All parts of the yew plant, including the leaves and berries contain taxine and are toxic to your dog when eaten. Ingesting yew can cause difficulty breathing, tremors, coma, and death. It's important to keep your dog away from these types of plants and remove them from your garden if possible.



Wisteria is a popular vine that is known for its cascading, colorful blooms. Unfortunately, the seeds and seed pods of the wisteria plant contain the toxins lectin and wisterin which are toxic to dogs. 

Common symptoms of wisteria poisoning in dogs includes:

  • Stomach upset 
  • Dehydration
  • Collapse
  • Vomiting
  • Diarrhea 

The seeds and seed pods themselves do not have a foul taste so your dog may continue to eat fatal amounts without knowing there is something wrong. If possible, try to avoid your dog coming into contact with the wisteria plant.



The best way to keep your dog safe from these harmful plants is by preventing exposure to the plants. Below are a few tips to help keep your dog safe outside.


1. Familiarize yourself with the plants in your garden or the ones you often encounter during walks. If you’re not sure what a particular plant is, try bringing a picture of it to your local garden center to see if anyone can help identify it for you. 


2. Create a dog-friendly space in your garden where your dog can play freely and not be exposed to these toxic plants. Pet-safe shrubs, flowers, and grasses can not only enhance your outdoor space but also reduce the risk of poisoning.


3. Keep a close eye on your dog whenever they are off-leash to ensure they don’t eat potentially harmful plants.


4. Teach your dog commands like "leave it" and "drop it.” These types of commands can help prevent your dog from eating anything harmful.


5. If you suspect your dog has ingested a poisonous plant, contact your veterinarian or the Pet Poison Helpline immediately. Be prepared to describe the plant, how much your dog ate, and any symptoms your dog is exhibiting. 



Lots of us pet parents take pride in our beautiful gardens. But by being aware of the harmful outdoor plants that are toxic for dogs, we can create safe and beautiful gardens for our dogs to enjoy. If you are at all concerned about your dog eating something poisonous, always speak to your veterinarian or call the Pet Poison Helpline. It is always best to be over-cautious in these types of situations.