When growing a garden, many plants add value and beauty to your that you may realize have some type of poisonous component. Whether it is from the berries, the flowers, or the leaves, it is important to know the capacity of a plant to have a detrimental effect. Additionally, some plants are perfectly fine around humans but can harm your pet or the outdoor animals that enjoy your garden.

Keep in mind that the word “poisonous” doesn’t mean toxic or deadly at every level. Many plants can simply lead to something like a rash on a person or digestive issues when consumed by animals.

Here are 20 common garden plants that have negative issues.

Baby’s breath

This delicate white breath of tiny petals is a lovely addition to any garden, but really should not be used in a garden where dogs are present. It causes stomach upset and can be dangerous because it tends to attract them.

Bleeding heart

Toxicity from bleeding hearts is rare with humans but it is a common poisoner to animals, especially dogs. It contains isoquinoline alkaloids that are very dangerous to animals’ liver and can cause seizures and nervous system damage.

Calla lily

These exceptionally elegant plants add a sense of luxury to any garden or home. Yet, like many poisonous garden plants, the calla lily contains insoluble calcium crystals that are released when a person or animal chews on or even bites into any part of the plant.

Foxglove

Foxgloves are true showstopper biennials in the garden that have stunning bell-like, freckled light purple flowers. They enjoy the dry shade and grow well in zones 4-10. However, they are one of the topmost toxic flowers that also happen to be highly common in a typical garden landscape. Every part of the foxglove plant is poisonous. They are poisonous to dogs, cats, outdoor animals, and, most importantly, to humans. They should not be grown in a home with small children.

Daffodil

Daffodils are beloved by gardeners for their easy growing and burst of pale yellow flowers against evergreen stalks in the beginning of spring or even late winter. However, the daffodil also contains both lycorine and calcium oxalate crystals. The bulb contains an even higher level of lycorine, which is toxic to pets and humans, bringing on stomach problems such as nausea, vomiting, and abdominal pain, and a higher intake can even lead to tremors, salivating convulsion.

Hydrangea

Although hydrangea is on this list, don’t worry too greatly about your prized hydrangea bushes, a spring, and summer staple, as they have symptoms but are rarely a huge health hazard. The stunning hydrangea bush is rarely fatal but can do contain cyanogenic glycoside that is poisonous to dogs, cats, and horses. The most common symptoms of a pet ingesting hydrangea leaves and flowers are stomach issues and lethargy.

Larkspur

This popular garden plant grows well in the summer months in regions that get less than an inch of rain a week. Larkspur has serious ramifications when ingested by animals. It can lead to symptoms the range from neuromuscular or respiratory paralysis to tremors and even death when ingested in larger quantities. Larkspur is an exceptionally gorgeous flower that often leaves children unable to resist touching or picking the blooms. However, even mild contact with the blooms can leave to skin irritation.

Lily of the Valley

This stunning, sweetly scented spring bloomer is native through the cooler northern temperatures. They are easily adaptable and grow well in full sun to partial shade. All parts of the lily of the valley have the potential to be poisonous, causing digestive issues like stomach pain, nausea and vomiting. Lily of the valley also grows small red berries that are attractive to children but also cause similar symptoms.

Marigold

These little yellowish-orange flowers are attracted to plants because of the sap that they produce. However, the sap causes animals to be highly attractive to them. They are mildly toxic to dogs when the sap is eaten, but they generally are often used as a dog repellant. However, there is conflicting information about cats because marigolds sometimes actually attract cats, and if you should see your cat playing in the marigold bed, it is a good idea to give her or him a nice bath in mild soap and water.

Mountain laurel

Mountain laurel is a lovely, delicate plant that grows well in hardiness zones 5 through 9. However, it is a carrier of a dangerous poison that can be deadly to both humans and animals. Many people enjoy seeing it on the hiking or walking trails and attempt to pick up. Mountain laurel is poisonous from stem to leaves and it is always recommended to look, not touch.

Lantana

This garden staple is enjoyed for its small clusters of bright-colored flowers that typically bloom in shades of yellow, orange, red, and white. This plant is also known as Wild Sage, Yellow Sage, and Red Sage. When they are ingested, both the leaves and the blooms can cause digestive issues, depression, and potentially liver failure when ingested by children, dogs, and cats. They are highly toxic when ingested by farm animals such as horses, sheep, and other livestock, which are the animals that most commonly ingest it. However, many birds can consume it without much of an effect.

Wisteria

This breathtaking stunning lavender-colored flower contains velvety seed pods inside its petals. The seeds pods have the highest rate of toxicity, but all parts of the plant may cause dizziness, digestive issues, nausea, confusion, speech problems, and even collapsing when they are digested.

Castor Oil Plant

Castor oil has been used for many homeopathic remedies for centuries, from relieving constipation to helping induce labor. Castor oil plants contain ricin that has its highest concentration in the seeds of the plants. This can cause tremors, dehydration, and is especially toxic to animals. The seeds or beans have a hard outer shell that can prevent the digestion absorption, but it is always best not to risk it.

Oleander

These dainty, light pink blowers are lovely to look at but are highly poisonous, even deadly. Even a light touch of the plant can cause skin irritation that can worsen to dermatitis. When ingested, it can cause cardiac episodes that can become as serious as a heart attack.

Azalea

These exceptionally stunning spring bloomers contain elements called grayanotoxins that are present in every part of the plant and are toxic to dogs and cats. Ingestion hinders the day-to-day function of muscle functions in both humans and animals and can block certain nerve functions.

Philodendron

These plants are commonly used indoors and in semi-tropic landscaping. Eating any part of the philodendron plant may lead to digestive issues and burning of the lips and throat. If a dog ingest a modest amount of philodendron they can have potentially fatal respiratory and stomach issues and should be taken to a vet immediately.

Morning Glory

These stunning, trumpet-shaped blooms are treasured for their shades of purple, pink, blues, whites, and several of bicolor mixes. The ingestion of the bloom itself has no major dangers associated with it, but the seeds can be poisonous when they are consumers in large quantities and contain a chemical that has similar hallucinogenic effects as LSD.

Angel’s Trumpet

These lovely flowers are considered poisonous in every part of the plant. They contain several alkaloids, including hyoscyamine, scopolamine, and atropine. There are many side effects, including memory loss, hallucinations, tremors, paralysis, and they can even be fatal. They shouldn’t be grown in gardens frequented by children or pets.

Autumn Crocus

A member of the lily family, these fall-flowering flowers are poisonous when any part is ingested, but the seeds and flowers are the most potent and contain high concentrations of colchicine. There are severe issues that can occur, including vomiting, bleeding of the stomach lining, living and kidney damage, tremors and seizures, and even death. It is toxic for pets and humans and should only be planted in an adult-only environment.

Peruvian Lily

These charming flowers bloom with delicate flowers containing a cluster of freckles on the top petals. They contain a toxin called tulipalin that causes moderate gastrointestinal problems. If ingested frequently over a long period of in a large quantity at once it can lead to acute kidney failure in cats and dogs.