Some garden plants harmful to people, pets

Tulips at the A. D, White House, the historic home of Cornell’s first president and co-founder, Andrew Dickson White, who had the Victorian villa built in 1871 for his use as university president. (Photo provided — Cornell University)

The types of plants we choose for our flower gardens are mostly a matter of personal preference. But, as we welcome the arrival of spring flowers, and with the promise of summer still ahead, it’s important that we know which of those plants our four-legged friends can check out or play in safely.

Many popular spring flowers are among the more than 700 plants that produce compounds which have been identified as being toxic to people and/or pets.

The following are just three of the most common spring garden flowers that can cause harm (or worse) if eaten by a much-loved pet.


Daffodils (scientific name Narcissus) are an extremely popular spring flower choice with gardeners everywhere. They’re reliable, easy to grow, deer-resistant and great for naturalizing.

Native to northern Europe and the official flower of Wales, daffodils are now grown in temperate climates around the world. There are at least 50 species, with many thousands of hybrid varieties. Every spring, almost 100,000 daffodils bloom in Cornell University’s Botanic Gardens.

Daffodils are potentially poisonous to people — especially to small children — as well as to pets, including horses, dogs and cats. In fact, there are recorded cases of cats becoming sick after drinking water from a vase that previously held daffodils.

Handling or chewing on any part of the plant may cause a burning sensation on skin or in the mouth. Conceivably, that burning sensation can act as a warning sign.

Pets (and people) ingesting any part of the plant may suffer diarrhea, vomiting, convulsions and a drop in blood pressure. It’s the plant’s bulb, however, that’s most toxic. Ingesting the bulb may result in any or all of the aforementioned symptoms, as well as excessive salivation, tremors, and cardiac arrhythmia (heart rhythm problems). Larger ingestions will result in more-severe symptoms.


Native to central Asia and Turkey, tulips became a symbol of the Ottoman Empire in the 10th century A.D. They were introduced to the Western world around 1560 A.D., marking the beginning of the horticultural tulip industry in Europe.

Today, tulips may be the most popular of all ornamental garden flowers and perhaps, the most widely-recognized of all spring blooms. Currently, there are more than 3,000 registered cultivars worldwide.

Every year, Cornell University Flower Bulb Research Program academics trial 18 to 25 new and emerging tulip cultivars under forcing conditions. Varieties are chosen based on presumed acceptance by U.S. markets.

During World War II, people in Europe were often hungry. In the Netherlands, some tried eating tulip bulbs, presumably because the bulb were visually similar to onions. Or maybe because there simply was nothing else to eat. Either way, this often resulted in grievous consequences.

All parts of the tulip are poisonous to people and pets, with the highest concentration of toxins found in the bulbs. Oral intake can cause intense gastrointestinal irritation, significant vomiting, diarrhea, shortness of breath, weakness, increased salivation, sweating, drooling, loss of appetite, dehydration, lethargy, abdominal pain, depression of the central nervous system, convulsions and/or cardiac abnormalities. More pronounced symptoms are seen when larger amounts, in relation to body weight, are ingested.


Lilies are extremely popular around the world and are commonly seen in garden beds and borders. They’re among the oldest cultivated plants and have naturalized throughout much of southern Europe and North Africa.

Lilies are depicted in paintings made by the Minoans, a Bronze Age civilization which inhabited the island of Crete from around 3000 B.C. to about 1100 B.C.

The ancient Greeks and Romans grew lilies for both ornamental and medicinal purposes. The Roman naturalist, Pliny the Elder, crushed the bulbs and used the ointment as a treatment for burns and inflammation, as did the Egyptians.

During the Middle Ages, those lilies became known as Madonna lilies and were associated with the Virgin Mary, as a symbol of purity. They’re often seen in medieval artworks of her.

From 1963 to 1999, the Madonna lily was the official flower of Quebec (perhaps a reference to the fleurs-de-lis on the provincial flag).

While lily flowers are lovely, all varieties of lilies, including Asiatic lilies, Oriental lilies, Easter lilies, daylilies, and lily-of-the-valley, can be poisonous to both canine and feline friends.

The entire plant is toxic, but only mildly toxic to most dogs. But, if a cat eats even just a small amount of a leaf or flower petal, licks a few grains of pollen off its fur while grooming or, as with daffodils, drinks the water from a vase that held lilies as cut flowers, it may develop fatal kidney failure in just a matter of days.

Early signs of lily toxicity in cats include lethargy, drooling, vomiting and loss of appetite. Lily-of-the-valley contains toxins that may cause cardiac arrhythmia.

Other garden dangers

Fertilizers, when ingested, can cause vomiting, diarrhea, and in some cases, weakness or stiffness in a pet’s hind legs.

Note too, that bone meal, fish emulsion, and several other organic fertilizers and soil amendments can be attractive to curious pets, especially dogs that like to dig.

Store pesticides and fertilizers in secure, labeled containers. And if you apply pesticides, always read the label thoroughly to learn when it’s safe for your pets to enter the garden, following an application.

Secure your compost bin too, so that your dog or cat doesn’t feast on the contents.

One last thought, while we’re on the subject.

Young children like to eat unknown, eye-catching plants and berries and, because of this, should be watched closely when playing outdoors.


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