10 Toxic Summertime Plants

Foliage to Keep Away from Pets

Our green thumbs often reappear during the warmer seasonal months, as we are inspired to banish dull winter months with bright, blossoming plants and flower beds.

For those of us with dogs and cats, however, which of these plants should we yield caution to and prevent accidental poisoning?

We asked the Pet Poison Helpline to help identify the most toxic summertime plants for pets.

Popular Summertime Plants Harmful to Pets

According to the Pet Poison Helpline, the seasonal plants poisoning pets the most during the months of May through August include:

Daffodil
  • Azalea/rhododendron
  • Crocus
  • Daffodil
  • Foxglove
  • Hyacinth
  • Lily of the Valley
  • Oleander
  • Sago palms
  • Tulip
  • Yew

In some cases, the entire plant is toxic but in some cases it may just be the bulb, stem, leaf or petal of the plant that is poisonous.

Dr. Ahna Brutlag, the associate director of Veterinary Services and a senior veterinary toxicologist at Pet Poison Helpline further explains that when it comes to bulbs in particular, one part is more toxic than the other.

“The flesh of bulbs such as a crocus, tulip and hyacinth is most toxic than the flesh of the plants themselves. In the case of the daffodil, the flesh of the plant is more harmful than that of the crocus, tulip or hyacinth.”

Choose Fertilizer Wisely

Did you know organic fertilizers are more dangerous to pets than other fertilizers?

While they’re a great natural source of nitrogen and utilize unused animal products, they’re often made of bone, blood or feather meal. These strong, appealingly-scented ingredients are very enticing to dogs and will often be eaten along with the poisonous bulbs.

While organic fertilizers on their own are not life threatening, they can cause an obstruction in the dog’s stomach, and also lead to vomiting, diarrhea and pancreatitis.

Signs of Toxic Ingestion

If you suspect your dog or cat has ingested a toxic plant, contact your veterinarian immediately. If you don’t have access to a 24-hour veterinarian, the Pet Poison Helpline's emergency hotline (1-855-289-0358) is available 24-hours a day.

Cat in flower field

Signs that your dog or cat may have ingested a toxic plant include:

  • Decreased heart rate
  • Diarrhea
  • Increased heart rate
  • Lethargy  
  • Pancreatitis
  • Seizures
  • Severe cardiac arrhythmias
  • Vomiting
Pet Poison Helpline

Vulnerability to plant toxicities depends on pet species, amount ingested and the size of your pet.

It is probably best not to have any poisonous plants around pets. Sprays sold in pet stores or nurseries to keep pets away from plants are often not very effective.


A $59 USD per-incident fee applies when calling the Pet Poison Helpline. This fee is not affiliated with the Pet HealthZone or Nationwide pet insurance. Nationwide pet insurance members can contact the Pet Poison Helpline at no cost through a members-only phone number that is located in the Nationwide member portal.


Know someone with pets?

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