Are Hydrangeas Poisonous to Cats? A Complete NYC Pet & Garden Safety Guide

Hydrangeas are among the most admired flowers in the world, known for their lush blooms and stunning color transformations. But if you share your home with pets, there’s one question that takes priority before planting or arranging them — are hydrangeas poisonous to cats?

The answer is yes. Hydrangeas contain compounds that can be harmful to cats if eaten. That doesn’t mean you have to give them up entirely, but it does mean you should understand the risks and take precautions so both your garden and your pets can thrive.

Are Hydrangeas Poisonous to Cats?

Hydrangeas contain a naturally occurring compound called cyanogenic glycoside. This substance is present in the leaves, buds, and flowers, and when digested, it can release cyanide, which is toxic to animals. If a cat chews or swallows any part of the plant, it can lead to illness.

Symptoms of hydrangea poisoning in cats can include drooling, vomiting, diarrhea, loss of appetite, and lethargy. In most cases, severe poisoning happens only when a cat ingests a large amount, but any suspected contact should be treated seriously. If your cat has been near or bitten a hydrangea, it’s best to call your veterinarian immediately.

Are Hydrangeas Poisonous to Dogs?

Hydrangeas are also toxic to dogs for the same reason they are to cats. Curious dogs may chew on garden plants or outdoor arrangements, making them vulnerable to the same risks. If a dog eats hydrangea leaves, flowers, or stems, symptoms can mirror those seen in cats, including stomach upset, weakness, and lack of appetite. As with cats, quick veterinary advice is essential if exposure occurs.

Are Hydrangeas Poisonous to Humans?

While hydrangea toxicity is most often discussed in the context of pets, it’s worth noting that they can also be harmful to people. Eating large quantities can cause stomach discomfort and nausea. In a home with small children, keeping hydrangeas out of reach is an important safety step.

Are Hydrangeas Deer Resistant?

Many gardeners hope hydrangeas will deter deer, but the truth is that they are not fully deer-resistant. Deer may ignore hydrangeas when other plants are available, but in many areas, especially in early spring when food is scarce, deer will happily browse on fresh hydrangea leaves and buds.

Do Deer Eat Hydrangeas?

Deer do eat hydrangeas, and they can damage them quickly if they have the opportunity. The tender new growth is particularly appealing. In suburban neighborhoods or properties close to wooded areas, hydrangea damage from deer is a common frustration for gardeners.

Will Deer Eat Hydrangeas in Winter?

During the winter months, when vegetation is limited, deer may nibble on hydrangea stems and buds. This damage can affect the plant’s ability to bloom the following spring. Protective measures like burlap wrapping or wire mesh can help safeguard plants through the cold season.

How to Enjoy Hydrangeas Safely in a Pet-Friendly Home

You don’t have to give up hydrangeas to keep your pets safe. The key is thoughtful placement and design. Indoor hydrangea arrangements can be displayed on shelves, mantels, or tables where cats and dogs can’t reach. Outdoor hydrangeas can be planted in raised planters or behind fencing to keep curious pets away. Choosing pet-safe flowers for high-traffic areas and reserving hydrangeas for controlled spaces allows you to enjoy their beauty without worry.

Why This Matters for NYC Gardeners and Florists

In New York City, where gardens are often compact and pets share space closely with plants, it’s especially important to design with safety in mind. Balcony planters, rooftop gardens, and small backyards can make it easier to control pet access to hydrangeas. Florists and event designers can also help clients choose arrangements that suit their lifestyle, offering hydrangeas in safe, elevated displays for pet-friendly homes.

Bring Hydrangea Beauty Home — Safely

At Black Petals, we specialize in premium hydrangeas that are perfect for elegant arrangements, events, and seasonal décor. We understand the needs of pet owners and can guide you on safe placement and display so you can enjoy the lush beauty of hydrangeas without risking your furry friends. Whether you’re refreshing your home with a bouquet or creating a garden statement, our flowers are sourced for quality and style.

Order your hydrangeas today and create a space that blooms with beauty — and peace of mind.