Are Hydrangeas Poisonous?

Hydrangeas are popular in gardens because they produce beautiful flowers. They grow as climbing vines and trees, and people often grow them as shrubs. They can be anywhere from one foot to 100 feet tall, and they bloom in pink, blue, lavender, purple, and other bright colors. 

Hydrangeas are poisonous, and they are not edible. They contain cyanogenic glycoside in the buds, flowers, and leaves, and they cause diarrhea, vomiting, and depression. If your children or pets ingest hydrangeas, you need to seek medical attention, even if they are not yet showing symptoms. 

Are Hydrangeas Poisonous to People?

All parts of the hydrangeas plant are poisonous to people, including the buds, flowers, and leaves. They are toxic to people because they contain a cyanogenic glycoside called hydrangin. It will convert to cyanide in the stomach and cause illness and irritation. 

Touching hydrangeas can cause a rash or skin irritation as well. This is much more likely for small children. The symptoms include vomiting, diarrhea, and depression. In addition, they can experience lightheadedness, shortness of breath, and overall weakness. To experience severe symptoms, it is necessary to consume large amounts of hydrangeas, so it is actually rare. 

Although it is safe to grow hydrangeas in your yard, if you have small children, it is better to avoid them. You can also erect a small fence around poisonous plants such as hydrangeas. You should make sure that the fence does block the plant from anyone being able to touch it. 

Are Hydrangeas Poisonous to Dogs?

All parts of the hydrangeas plant are poisonous to dogs. The same toxin that is dangerous for people is toxic to dogs: cyanogenic glucoside. The leaves, flowers, buds, and bark all contain this compound, so your dog can become ill from eating any part of the plant. 

If your dog eats hydrangeas, you might notice any of the following symptoms:

  • Reduced appetite
  • Vomiting
  • Diarrhea
  • Abdominal discomfort
  • Depression

If your dog eats a lot of hydrangeas, it might have a fever and increased heart rate. Your dog will need to see the vet right away. They will provide supportive care, which could include anti-nausea medicine, anti-diarrhea medicine, pain relief, and fluids. If your vet isn’t available or it is after hours, seek treatment from an emergency vet clinic. 

Are Hydrangeas Poisonous to Cats?

Hydrangeas are poisonous to cats. The toxic compound, cyanogenic glycoside, is poisonous, and your cat will likely show signs of ingesting this toxin right away. The entire plant is toxic, so your cat can eat any part and suffer a reaction. You might notice your cat retching and vomiting, and it could have diarrhea or appear lethargic. 

It is important to seek vet care right away if your cat appears ill. Your cat needs to eat quite a bit of hydrangeas to suffer severe illnesses. You probably won’t see your cat eating the hydrangeas, so if you see it playing near a hydrangeas plant, you need to watch it for symptoms. 

Blue Hydrangea
Yay Blue Hydrangea

Symptoms start to occur around 30 minutes after ingestion. Once you get to the vet, they are likely to draw blood and make sure that your cat’s organs are functioning normally. You can also bring a sample of the hydrangeas and any nearby plants to help the vet identify what your cat may have eaten. 

Are Hydrangeas Poisonous to Livestock?

Hydrangeas are poisonous to horses, to goats, to cattle, to hogs, to chickens, and to sheep. They can cause toxicity in any farm animal. If your horse ingests hydrangeas, it will be poisoned by the cyanogenic glycoside, Hydrangin. This causes stomach irritation, and it can lead to cyanide intoxication, which can cause death. The compound breaks down in the liver, and it creates cyanide, which is fast acting. It can cause the following symptoms:

  • Difficulty breathing
  • Weakness
  • Lack of coordination
  • Convulsions
  • Coma
  • Death

Horses need to be hospitalized and receive supportive therapy, and it is very serious. Make sure that your horses are unable to access hydrangea on your property. 

Other farm animals suffer the same results. Hydrangeas are poisonous to chickens, and the leaves are deadly if the chickens eat a lot of them. You should make sure that you don’t have hydrangeas where they can access them. If your chickens are free range, they are pretty good about avoiding poisonous plants, but most animals when confined will eat whatever they can find. If you have hydrangeas, just plant them away from the chicken coop. 

Are Hydrangeas Poisonous to Wild Animals?

Hydrangeas are poisonous to rabbits for the same reason that they are poisonous to other animals: they contain cyanogenic glycoside. They can be dangerous for rabbits, but wild animals won’t normally ingest a lot of this plant. Deer will eat your hydrangeas, so they are not as toxic to deer as they are to other animals. It is important to make sure that you have a proper fence or some other way to keep the deer away. 

If you plant hydrangeas and don’t want the wild animals to eat them, you need to build a full fence and place wire cages around smaller plants. You can also plant climbing hydrangeas so that they grow out of reach of the deer. In addition, you can create a deer repellent out of an egg yoke, a liter of water, and a teaspoon of baking powder. Put it in a spray bottle, and you can spray the plants every two weeks. You can also plant plants that deer know to stay away from, including boxwoods, spirea, and lavender. 

Even though hydrangeas are poisonous, deer will eat them if they are hungry enough. This is true of most animals, so the best thing you can do is make sure that you plant your hydrangeas in a place where they are less likely to be eaten and protect them with a fence. Use the natural deer repellent spray for added protection. This will keep your hydrangeas safe and ensure that the deer can’t get to them. It will also help to keep your pets away, and your plants can grow.