12 Poisonous Flowers to Avoid in Your Garden

Pink azalea bushes in bloom

Van Hickman / EyeEm / Getty Images

Attractive or fragrant flowers often make us forget that the plants growing in our backyard or on the patio might be toxic for humans or pets.

Whether you are planning to add new plants to your flowerbeds, or you move into a new home and want to check whether the existing landscaping is safe for your children and four-legged best friends, here is a list of common nursery plants that have poisonous properties, and suggestions for alternatives. This list is not all-inclusive.

  • 01 of 12

    Lily of the Valley (Convallaria majalis)

    Lily of the Valley

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    In May, this shade-loving perennial ground cover develops stems with tiny, nodding, bell-shaped white flowers on one side of the stem. Your nose will also help you identify it: Lily of the valley has a characteristic sweet scent.

    Poisonous Parts: All parts of the plant if ingested

    Poisonous for: Humans, dogs, and cats

    Non-Toxic Alternative: Virginia spiderwort (Tradescantia virginiana)

  • 02 of 12

    Wisteria (Wisteria spp.)

    Wisteria

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    This vigorously climbing perennial vine has large showy clusters of fragrant blue or purple flowers in the spring. After blooming, wisteria produces large seedpods with a velvety capsule. After drying, they pop with a startling loud noise.

    Poisonous Parts: If ingested, all seed pods and seeds both of Chinese wisteria (Wisteria chinensis) and American wisteria (Wisteria frutescens)

    Poisonous for: Humans, dogs, and cats

    Non-Toxic Alternative: Magnifica honeysuckle

  • 03 of 12

    Lily (Lilium spp.)

    Daylily

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    Many lilies are highly toxic for cats. These include the Easter lily with white fragrant trumpet-shaped flowers, the deep-orange tiger lily with its typical brown spots, Asiatic and Japanese lilies, lily hybrids, and daylillies such as the popular Stella de Oro Daylily

    Poisonous: All parts of the plant if ingested

    Poisonous for: Cats

    Non-Toxic Alternative: Canna lilies and other lilies that are not members of the Lillium or Hemerocallis genus and therefore are not true lilies

  • 04 of 12

    Lantana (Lantana camara)

    Lantana

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    As a frost-tender evergreen shrub, lantana is often grown as a trailing plant and as an annual in colder climates. It has small dense flower clusters in white, yellow, orange, red and purple. Sometimes different colors are mixed in the same cluster. The leaves give off a citrus fragrance aromatic when crushed.

    Poisonous Parts: All parts of the plant if ingested

    Poisonous for: Humans, dogs, and cats

    Non-Toxic Alternative: Verbena

    Continue to 5 of 12 below.
  • 05 of 12

    Hydrangea (Hydrangea spp.)

    Hydrangea

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    There are countless varieties of hydrangea species and cultivars and they all stand out in the landscape by their large flowerheads that are shaped like large round mopheads, lacecaps, or long panicles.

    Poisonous Parts: Leaves, flowers, and bark if ingested

    Poisonous for: Humans, dogs, and cats

    Non-Toxic Alternative: Spirea

  • 06 of 12

    Foxglove (Digitalis purpurea)

    Foxglove

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    A close look at a flowering foxglove reveals its most prominent characteristic: The inside of the bell-shaped flowers has many purple to maroon spots with a white ring. The flowers are mostly bright purple, but there are also white, cream-colored yellow, pink, or rose cultivars.

    Poisonous Parts: All parts of the plant if ingested

    Poisonous for: Humans, dogs and cats

    Non-Toxic Alternative: Hollyhock

  • 07 of 12

    Oleander (Nerium oleander)

    Oleander

    Blanchi Costela / Getty Images

    You can identify an oleander shrub first and foremost by the fragrance of its white, purple, or pink flowers. When not in bloom, take a look at the leaves which are narrow and glossy with a distinctive midrib.

    Poisonous Parts: All parts of the plant if ingested

    Poisonous for: Humans, dogs and cats

    Warning

    Due to its high toxicity, Oleander is not recommended for households with small children or pets.

  • 08 of 12

    Rhododendron and Azalea (Rhododendron spp.)

    Azalea

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    During their bloom in April, all rhododendron and azaleas stand out by their abundance of lavender, rose, or pink flower clusters. The leaves are dark green, hairless, and leathery and turn purplish in the winter.

    Poisonous Parts: All parts of the plant if ingested

    Toxic to: Humans, dogs, and cats

    Non-Toxic Alternative: Lilac

    Continue to 9 of 12 below.
  • 09 of 12

    Mountain Laurel (Kalmia latifolia)

    Mountain Laurel

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    The flower clusters of this broadleaf evergreen shrub are sometimes compared to tiny bowls or bells. The inside of each flower has symmetrical with dark rose- or maroon-colored dots and streaks. 

    Poisonous Parts: All parts of the plant if ingested

    Poisonous for: Humans, dogs, and cats

    Non-Toxic Alternative: Dogwood

  • 10 of 12

    Monkshood (Aconitum)

    Monkshood

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    Monkshood flowers have two distinct characteristics – their striking deep purplish-blue to violet color, and an upper sepal in the shape of a hood like the one worn by medieval monks, which gave the plant its common name.

    Poisonous Parts: All parts of the plant if ingested

    Poisonous to: Humans, dogs and cats.

    Because of its high toxicity of monkshood even upon skin contact, it is not a recommended choice unless gardening with proper protective gear.

  • 11 of 12

    Angel’s Trumpet (Brugmansia)

    Angel's Trumpet

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    As a tropical small tree or shrub, angel’s trumpet is grown in containers in colder climates. The large, drooping flowers come in white, peach, pink, orange or yellow and can grow up to 20 inches long.

    Poisonous Parts: All parts of the plant if ingested

    Poisonous for: Humans, dogs, and cats

    Because of the high toxicity of this plant even when handling it, angel’s trumpet is not recommended if skin contact or ingestion by children or pets is a possibility.

  • 12 of 12

    Fall Crocus (Colchium autumnale)

    Fall Crocus

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    The fall crocus or autumn crocus, which blooms in early fall, has no foliage, unlike the spring crocus. The flower color ranges from lavender to lilac purple.

    Poisonous Parts: All parts of the plant if ingested

    Poisonous for: Humans, dogs, and cats

    If ingestion by children or pets is a possibility, planting crocuses, both summer and fall crocuses, in your yard is not recommended.