Planting Wisely: Toxic Landscaping Plants

Many homeowners, who purchase a new home, opt to have basic landscaping done as part of their home package, but then later fill in the flower beds and garden areas with more lush plantings gradually. But before you start digging, you should know that if you have young children or pets, a number of lovely posies can be toxic landscaping plants, and even fatal if ingested. Knowing these dangerous plants and avoiding them in your landscape will keep your loved ones safe.

Plant non-toxic landscaping!

The Most Toxic Landscaping Plants:

Whether it’s the foliage, the flowers or the berries, all of the following toxic landscaping plants should be avoided if you have children or pets: English Yew, Rhododendron, Lily of the Valley, Hydrangea, Narcissus, Daffodils, Foxglove, Larkspur, Oleander, Poinsettia, Purple Nightshade, Mountain Laurel, Mistletoe, Water Hemlock, Ficus, Wisteria, Sago Palm, Azalea, Bleeding Heart and Castor Bean. While this is not a complete list, these plants are some of the most commonly used in landscapes.

What They Do:

English Yew:

A very deadly evergreen tree. While majestic and lush in appearance, any part of this tree will cause rapid heart failure. There is no antidote to the poison.


Rhodedendron is Toxic

Produces drooling, tears, violent vomiting, slow pulse, low blood pressure, coma, seizure and finally death. Any part of the plant will do this when eaten.


Lillies are Poisonous

The entire lily family, including Lily of the Valley, Daylilies, and Easter Lilies, are toxic to both humans and pets. In humans, any part of the plant, when eaten, causes headache, hallucination, red blotchy skin, possibly coma and sometimes death. In pets, even pollen or water from a vase, will cause acute kidney failure and heart rhythm issues. If you see your pet eat a lily, rush them to the vet for detox immediately.


Hydrangeas are Toxic

While this gloriously colorful shrub was a staple in most Victorian gardens, you might want to avoid planting it, at least while your children are young. The hydrangea contains a form of cyanide and will cause shortness of breath, fainting, dizziness, rapid pulse, low blood pressure, convulsions and death. The flower buds are the most poisonous part.

Narcissus, Daffodil and Foxglove:

Narcissus is Toxic

These plants are related, and cause varying degrees of both skin sensitivity when touched and toxicity when eaten. Narcissus is entirely poisonous. If you have a cut on your finger when you touch the bulb, you can experience staggering, numbness and heart paralysis. Eating it will make you vomit, convulse, faint, become paralyzed and die. Daffodils may also cause skin irritation. If eaten, a daffodil will give you stomachache, nausea, dizziness, diarrhea and pain. Eating Foxglove causes blurred vision, hallucinations, irregular or slow heartbeat, low blood pressure, vomiting and fainting. If a child even sucks on part of the plant, they may die. Seek medical help immediately if any of these are ingested.


New growth and seeds are the most poisonous part of this plant. Eating it will cause weakness, staggering, drooling, muscle twitches, nausea, vomiting, irregular and rapid pulse and death. You have about a six-hour window to seek help before death will occur. This plant is a great danger to both pets and humans.


Oleander is toxic

This decorative shrub contains multiple toxins. A single leaf may kill an adult. All parts – wood, flowers, berries, roots – are dangerous. It will attack the heart, the digestive tract and the nervous system simultaneously. Death may result.


Toxic Poinsettia

This Christmastime lovely has poisonous sap. While death in humans is rare, it is more dangerous to pets, causing vomiting and diarrhea.

Purple Nightshade:

While the berries on this plant look lovely, when eaten, they paralyze your vocal chords and breathing and then cause severe intestinal contractions, full-body convulsions and finally death. The most dangerous parts of the purple nightshade are the berries, roots and leaves.

Mountain Laurel:

The state flower of PA and CT, mountain laurel shrubs are akin to rhododendrons and azaleas. Parts of the plant which are toxic include the plant itself, flowers, pollen and twigs. In fact, honey derived from mountain laurel is also poisonous. Symptoms manifest as drooling, rough breathing, eyes and nose watering, heart complications, convulsions, paralysis and finally death.


Mistletoe is poisonous

Although at Christmastime, people display the mistletoe plant inside their homes, all parts of it are poisonous if you eat them. Different varieties of mistletoe have varying degrees of toxicity. Symptoms include vision blurring, stomach pain, nausea, diarrhea, low blood pressure and sometimes death.

Water Hemlock:

This plant is the most toxic in North America. When eaten, it causes violent convulsions which turn into grand mal seizures. Death follows. All parts of the water hemlock, including the roots and seeds, are poisonous. By the way, water hemlock flowers closely resemble Queen Anne’s Lace flowers. Both are related to the carrot family of plants, but Queen Anne’s Lace is not toxic. The way to tell the difference is to look for a purple-red dot in the center of the flower cluster – that is Queen Anne’s Lace. Water Hemlock does not have the reddish dot in the center.


Ficus trees are only mildly poisonous. The main part which causes issues is the sap. If a child touches the sap, they may experience a skin rash which itches. In pets, the ficus tree sap produces both tummy troubles and skin irritation.


Wisteria is Poisonous

These cascading lovelies can be quite attractive to children and pets. The toxin is in the seeds, seed pods and bark, and it causes stomach upset, vomiting, diarrhea, shortness of breath and even death, if the child or pet eats a large quantity.

Sago Palm:

Toxic Sago Palm

The sago palm attracts both cats and dogs to chew on the leaves. If this happens, seek help immediately. The toxin begins by causing stomach upset and progresses to nervous system problems, liver failure and death, if untreated. The palm is also very poisonous to people.


Azalea is toxic

A close relative of the rhododendron, eating the azalea produces slow heart rate, very low blood pressure, coma, seizure and finally death. Even honey which bees make from Azalea pollen is toxic. In the springtime, children may mistake the azalea flower for honeysuckle and suck on the flower. Usually, this only creates an irritated mouth, nausea and vomiting. However, if a child or pet actually eats the flower, it can be fatal.

Bleeding Heart:

Bleeding Heart is toxic

All parts of the bleeding heart plant are toxic, both when eaten and when touched. A touch causes skin irritation. Eating the plant induces vomiting, diarrhea, convulsions and breathing difficulty.

Castor Bean:

toxic castor bean plant

The castor bean plant contains ricin, an extremely toxic substance. The ricin creates extreme gastroenteritis and eye damage. If the amount eaten is small, recovery is possible. While the seeds contain ricin, when they are processed commercially into castor oil, the ricin is removed. If a person or animal ingests castor beans or the foliage, seek treatment immediately.

If you are careful in your landscaping, your yard will be a safe haven for your children and pets. It’s far easier to avoid planting toxic landscaping plants than to try to get medical help when a poisonous calamity happens.  Here’s to happy (and healthy) gardening this summer!

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