Short answer
Hollyhocks (Alcea rosea) are listed as non-toxic to dogs on the ASPCA’s toxic and non-toxic plants list. That makes them a lower-risk choice for a dog-friendly garden than many popular flowers. “Non-toxic” does not mean “good to eat,” though. A dog that chews a lot of any plant can end up with an upset stomach, and the way a plant has been treated can matter more than the plant itself.
What the ASPCA list says
The ASPCA classifies hollyhock as non-toxic to dogs, cats, and horses. If you want to double-check, search the plant’s common and botanical name in the ASPCA database, since lists get updated. Remember that the database covers the plant itself, not the fertilizers, pesticides, or fungicides that might be on it.
Minor issues to know about
- Plant hairs. Hollyhock stems and leaves are somewhat hairy and rough. In some dogs, chewing or rubbing against them may cause mouth irritation or skin itching.
- Stomach upset. Eating a large amount of any plant material can lead to vomiting or loose stools. This is usually mild and short-lived, but call your vet if it persists or your dog seems unwell (see when to see a vet for dog diarrhea).
- Choking or blockage. Tall, fibrous stems are not meant to be swallowed in large pieces. Dogs that swallow big chunks of plants can have trouble, so contact your vet if you see repeated retching, abdominal pain, or an inability to keep food down. Our article on dog intestinal blockage lists the warning signs.
Do not confuse hollyhock with holly
Despite similar names, hollyhock is unrelated to true holly (Ilex species), such as English holly. Holly is listed as toxic to dogs and can cause vomiting and diarrhea. If you are shopping for plants or reading a list, confirm the botanical name to avoid mix-ups.
Garden treatments matter more than the plant
Hollyhocks are prone to problems such as rust and pests, so gardeners may be tempted to spray them. Check product labels carefully, keep dogs away from treated plants until the product has dried or for as long as instructions state, and store everything out of reach. If your dog has eaten a plant that was recently sprayed, or any garden chemical, call your veterinarian or the ASPCA Animal Poison Control Center at (888) 426-4435 (a consultation fee may apply) and have the product label ready.
Do hollyhocks grow back every year?
Hollyhocks are often grown as biennials or short-lived perennials. They commonly flower in their second year and then self-seed, so new plants often appear nearby. Results vary by climate and care. This is useful to know if you are planning a border, because the plants may move around the garden over time.
Which animals eat hollyhocks?
Hollyhocks can attract chewing pests, including deer and rabbits in some areas, along with insects such as beetles. Your dog may also show interest. If damage is heavy, check which animal is responsible before applying anything to the plants, and choose approaches that are safe around pets.
When to call a vet
Contact your veterinarian if your dog:
- Vomits more than once or has diarrhea that continues
- Seems lethargic, painful, or stops eating
- Has persistent drooling, pawing at the mouth, or skin redness after contact
- May have eaten a sprayed plant or garden product
- Has eaten a lot of plant material and you are unsure what to expect
What is the most poisonous plant for a dog?
There is no single answer, since it depends on the amount eaten, the size of the dog, and the part of the plant. Plants frequently listed as dangerous include sago palm, oleander, yew, and autumn crocus, among others. Our article on verbena explains how lookalike plants such as lantana can cause confusion. For your own garden, check every plant against the ASPCA list, and talk to your vet if you are not sure.