Some of the Prettiest Backyard Plants Aren’t Safe for Cats
A flower-filled backyard can contain plants that pose a risk to cats that spend time outside. Hydrangeas, lavender, calla lilies, hostas, yarrow, and plants in the Allium genus can all create problems if a cat chews or eats them, even though they are common choices for garden beds.
The risk is not the same for every plant. Some cause stomach upset or irritation, while others can produce more serious effects. If cats have access to the garden, knowing what is growing among the flowers and foliage matters before adding another plant.
Hydrangeas Can Cause Stomach Problems in Cats
Blue hydrangeas fill this shaded garden with broad green leaves and clusters of blue-purple flowers. Hydrangeas contain cyanogenic glycosides, and the ASPCA lists them as toxic to cats, dogs, and horses.
A cat that eats hydrangea may develop vomiting, diarrhea, or depression. The ASPCA notes that cyanide poisoning is rare and that exposure tends to cause gastrointestinal problems, but hydrangeas are still a plant to skip where a cat has access to the beds.
Yarrow Adds Color but Poses a Risk to Cats
Flat yellow flower heads stand among purple blooms, tall stems, and grasses in this mixed border. The yellow flowers appear to be yarrow, or Achillea millefolium, a perennial that can spread through a bed and produce clusters of small flowers.
Yarrow is toxic to cats and contains compounds including achillein and sesquiterpene lactones. Eating it can lead to vomiting, diarrhea, drooling, loss of appetite, depression, and other symptoms.
Lavender Isn’t a Cat-Safe Choice
Dense rows of lavender run beside the wood path, using narrow green foliage and purple flower spikes to form a low border. Its size and massed growth make it useful along paths, but that same placement can put the plant within reach of a cat moving through the garden.
The ASPCA lists English lavender, Lavandula angustifolia, as toxic to cats. Its toxic components include linalool and linalyl acetate, with nausea, vomiting, and loss of appetite among the listed signs after ingestion.
Ornamental Alliums Need Care Around Cats
Large purple globe-shaped flower heads rise above the surrounding planting in this garden. They are ornamental alliums, members of the same genus that includes onions, garlic, chives, and leeks.
Allium plants are a concern for cats because members of the genus contain compounds that can damage red blood cells. ASPCA entries for onion, garlic, chives, and leek list effects that can include vomiting, weakness, blood in the urine, increased heart rate, and hemolytic anemia.
Calla Lilies Can Irritate a Cat’s Mouth
Pink, burgundy, purple, and near-black calla lilies form the dense planting in this image. Their curved flowers and broad green leaves make them stand out in a bed, but calla lilies are not a safe choice for a garden a cat can reach.
Calla lilies contain insoluble calcium oxalate crystals. A cat that bites the plant can develop burning and irritation of the mouth, tongue, and lips, along with drooling, vomiting, and trouble swallowing.
Hostas Put Toxic Foliage at Ground Level
Large hosta leaves fill the right side of this planting, paired with ferns and other shade plants. Their low growth puts the foliage close to the ground, where a cat exploring beneath taller plants can reach it without climbing.
Hostas contain saponins and are listed as toxic to cats. Ingestion can cause vomiting, diarrhea, and depression, making them another common shade-garden plant worth avoiding in areas used by pets.
Yarrow Can Hide Among Ornamental Grasses
Pink and pale yellow yarrow flower heads rise through fine ornamental grasses in this planting. The combination shows how a toxic plant does not have to dominate a garden bed to become accessible to a cat moving through the foliage.
The same warning applies regardless of flower color. Achillea millefolium is listed as toxic to cats, so pink, yellow, or white forms should not be treated as cat-safe because they look different from the more familiar white-flowering plant.