Common Backyard Plants That Are Poisonous to Dogs

Daffodils with long trumpets (image) are classic. Other forms do exist, too.
Daffodils trumpet spring's return but are quite poisonous. David Beaulieu

Many plants poisonous to dogs are very common in backyards. These toxic time-bombs range from being only mildly toxic (for example, causing vomiting) to being responsible for more serious canine health problems. If you wish to err on the safe side, thoroughly research any vegetation, berries, etc. to which your canine friend has access.

In the case of some plants that pose a danger, only a particular part of the life form in question will be toxic -- that is, the seed, leaves, etc.

But it is beyond the scope of this article to delve into those details. I am a landscaping enthusiast, not a toxicologist, so further questions should be addressed to those more expert in the field than I. Nor is the following list of plants poisonous to dogs intended in any way to be complete. Rather, it is a sampling of the lists of plants poisonous to dogs provided by such organizations as the ASPCA and the Humane Society; consider the list as a springboard to further research. Many (but not necessarily all) of the examples on my list are also toxic to cats and humans as well.

I have organized this list of plants poisonous to dogs according to type (vines, shrubs, etc.), as an indication of the potential scope of the problem, as well as to make the plant list easier to read.

Cold-Hardy, Perennial Flowers

The toxic nature of some of the plants poisonous to dogs will probably come as no surprise to some of you.

The danger posed by foxglove, for example, is fairly common knowledge. A few plants, such as dogbane, even announce their toxicity in their very names. Would that it were always that easy to determine which plants can make your dog sick! The only other entry on this list that gives itself away so easily is monkshood, provided that you know its other common name, which is "wolfsbane":​​​​​

  1. Foxglove
  2. Mums
  3. Lenten rose
  4. Lily-of-the-valley
  5. Hosta
  6. Bleeding hearts
  7. Iris
  8. Monkshood
  9. Yarrow

Vines

Many vines, including those listed below, have the potential to be invasive plants. But vines are also incredibly versatile, serving many a landscaping need. If you own a canine friend who has the run of the yard, just make sure you choose vines that, unlike the following examples, are not plants poisonous to dogs:

  1. English ivy
  2. Morning glory
  3. Wisteria
  4. Clematis
  5. Bittersweet
  6. Boston ivy

Annuals

Annuals are sold in droves at garden centers and valued for the instant, long-lasting color they can inject into one's landscaping. But select carefully if you have a dog that goes outdoors and tends to eat your flowers, because some are poisonous, including:

  1. Lantana
  2. Begonias

In the North, where lantana is treated as an annual, it is popular in hanging baskets, in which its lively flowers grace many a porch or patio. Not only is lantana an invasive shrub in warmer areas (where it is not annual), however, but it is also toxic. Growing the plant up high in a hanging basket thus serves two purposes (which is why even Southerners should consider growing the plant in this fashion):

  1. The plant is contained, so it is less likely to spread.
  2. It is located at a height where your dog will not be able to reach it.

Shrubs

Shrubs, along with trees and hardscape, help supply a "backbone" for the yard. My list of shrubs offers a glimpse into some of the possibilities these workhorses of the landscape provide. But several shrubs are plants poisonous to dogs, including the following:

  1. Rose of Sharon
  2. Yew
  3. Mountain laurel
  4. Hydrangeas
  5. Burning bush
  6. Azaleas and rhododendrons
  7. Boxwood
  8. Privet
  9. Daphne
  10. Andromeda (Pieris japonica)

Trees

"An apple a day keeps the doctor away"? Our faith in this maxim is not shaken by the well-known fact that apple seeds contain cyanide. Nor should it be. But according to the ASPCA, even the leaves of apple trees are toxic, and The Merck Veterinary Manual confirms this claim. Since the Hawthorns are related to apples, it should come as no surprise that Washington hawthorn trees, for example, are poisonous to canines. Here are some other examples:

  1. Oleander
  2. American holly (Ilex opaca)
  3. Yellow bird of paradise (Caesalpinia gilliesii)
  4. Golden chain (Laburnum × watereri)
  5. Oak trees (leaves and acorns poisonous to dogs)

Bulb Plants

You may have heard that squirrels -- a major pest for many other spring-flowering bulb plants -- will not eat daffodils. But do you know why? The fact is, daffodils are toxic. Other bulbs to be careful about if you have a dog include:

  1. Hyacinths
  2. Tulips
  3. Lilies
  4. Alliums

Tropical Plants

Some landscaping stalwarts (including some tropical plants) are grown for their flowers, but others are grown for their vegetation. We sometimes refer to them as foliage plants. Some of these plant specimens poisonous to dogs are also known for having large leaves, such as castor beans and the aptly-named "elephant ears" (​Colocasia). By contrast, bird of paradise and angel's trumpet are clearly grown for their sensational blossoms. Meanwhile, ​Aloe Vera may be toxic for your puppy, but it is found in many skin-care products for humans. As for snake lily, this unusual specimen is in a class all by itself:

  1. Castor bean
  2. Elephant ears
  3. Aloe vera
  4. Bird of paradise
  5. Angel's trumpet
  6. Snake Lily

Weeds and Other Wild Plants

Finally, as if weeds did not already give us fits in trying to control them, there are also some weeds that are poisonous to dogs.  Yellow dock has some upside: namely, its leaves can be crushed to create a salve for stinging nettle burns. Meanwhile, Mayapple, baneberry, bloodroot, and jack-in-the-pulpit have a place in wildflower gardens, and mistletoe is, of course, a classic for Christmas decorating, as is another poisonous plant, the poinsettia:

  1. Yellow dock
  2. Bittersweet nightshade
  3. Creeping Charlie
  4. Mayapple
  5. Baneberry
  6. Bloodroot
  7. Jack-in-the-pulpit
  8. Mistletoe

If you know you have plants poisonous to dogs growing in your yard, it is a good idea to keep your dog from accessing them, perhaps via some type of fencing. But seedlings (especially of weeds) can sprout up very quickly, so also be sure to monitor the grounds within the fencing, to ensure that it remains free of toxic intruders. If your dog becomes ill and you suspect that it has eaten one of these poisonous plants, contact your veterinarian immediately if you wish to be on the safe side.