Oleander Plant Profile

Toxicity and Special Considerations

An oleander shrub with pink flowers

Ursula Alter / Getty Images

Oleander (Nerium oleander) is a fast-growing evergreen shrub that's hardy and fairly low maintenance. In fact, because of its hardiness, the plant is considered invasive in certain parts of the Southwest and around the Gulf Coast. It produces fragrant, showy clusters of flowers from around May to October, coming in several color varieties. Oleander is typically grown as a perennial landscape ornamental in warm climates, but it also can work as a container plant for sunny patios and decks. It grows 4 to 8 feet tall on average, with some cultivars reaching 20 feet high. While it's a beautiful shrub, all parts of it are toxic to people and animals. Ingesting any part can cause serious symptoms or even death. Skin contact also can result in irritation, such as rashes and sores. Plus, even smoke from burning the plant is toxic. 

Toxicity of Oleander

There are multiple poisonous elements to oleander. All of its parts—the flowers, leaves, stems, sap, etc.—are toxic, even when they’re dried or burned. The plant is a potent source of cardiac glycosides, which can cause irregular heart activity. Even eating a single leaf or drinking water from a vase with an oleander flower can be lethal to a small child, though the mortality rate is generally low in humans. 

Oleander can affect animals in the same way based on their size and how much they ingest. Poisonings typically occur in farm animals, such as cows and horses, when they are allowed to graze in areas where oleander is present. Plus, dogs and cats can be poisoned when they are allowed to investigate an oleander plant on someone’s property. Even wild birds succumb to the plant’s toxicity.

If you do choose to keep oleander on your property, make sure no children or pets can come in contact with it. Also, wear long sleeves, pants, and gloves when working with your shrub. And consider planting one of the smaller varieties, so it’s easier to manage.

Symptoms of Poisoning

Symptoms generally show up within hours of contacting the plant. And in some cases, especially with small animals and young children ingesting the plant, the first sign that a poisoning took place is unfortunately death. 

The following are some moderate to severe symptoms that a person or animal might experience from oleander:

  • Irregular heartbeat
  • Low blood pressure
  • Vision disturbances
  • Diarrhea, nausea, vomiting, or stomach pain
  • Loss of appetite
  • Weakness
  • Confusion
  • Dizziness
  • Fatigue
  • Difficulty breathing
  • Rash or hives

Moderate cases last one to three days on average; severe cases might require hospitalization. If you suspect oleander poisoning has taken place, contact a health care provider or poison control center immediately. 

Gardening Considerations

In the garden, some people use oleander shrubs as hedges, screens, and borders. While they provide excellent ornamental value, they also can crowd out less hardy garden plants. Oleander is native to dry and rocky Mediterranean soil, so it's able to tolerate poor soil and some drought. Its roots are also known to readily spread and become invasive. So if you ever want to remove your shrub, it can be a difficult task to rid your soil of its extensive root system.

Botanical Name Nerium oleander
Common Name Oleander
Plant Type Evergreen shrub or small tree
Mature Size 4 to 8 feet tall on average
Bloom Time Spring through fall
Flower Color Pink, purple, red, yellow, white

Identification

Oleander has an upright, rounded growth habit with a slightly smaller spread than height. During the warmer months, the shrub is full of showy, five-petaled flowers that grow in clusters on each stem. It sports narrow, dark green, lance-shaped leaves that are roughly 4 to 7 inches long. On young plants, the leaves are more of a glossy, light green color.

Where It's Found

Oleander is native to the Mediterranean region, and it’s been naturalized in many parts of Europe and Asia. In the United States, it’s hardy in growing zones 8 to 10, though some gardeners in cooler climates are able to overwinter it as a container plant indoors.

The shrub is typically found growing around stream beds that occasionally experience drought. It can tolerate some frost but struggles once the temperature falls below 20 degrees Fahrenheit. Oleander prefers average soil with a neutral pH, medium moisture, and good drainage. Its growing site should get partial to full sunlight.

How to Remove Oleander

Because of its fast growth habit and extensive root system, oleander isn’t easy to get rid of. Chemical herbicides are the fastest way to remove unwanted oleander. But they also can be highly toxic to the environment and dangerous for any people and animals who come in contact with them. Plus, herbicides can kill plants that you want to keep in your garden. 

So if you wish to avoid chemicals, you should be prepared for a longer and more labor-intensive process to remove the oleander. The goal is to take out all of its roots. To do so, first cut the entire shrub to its base while wearing protective clothing. Be careful to gather and properly dispose of all parts of the plant. A helpful method is to put all of your cuttings on a tarp, so you don’t lose any.

Next, water the soil around the stump well to make it more workable. Dig around the perimeter, and pry up as much of the root system as possible. You might need to enlist help to lift the stump and roots out of the ground. Finally, continue to dig in the soil to remove any remaining roots. If any regrowth in the area occurs, get rid of the new shoots as soon as possible by digging them up from the roots.

Varieties of Oleander

There are several varieties of oleander, which vary slightly in color, size, and other qualities. They include:

  • 'Pink Beauty' (Nerium oleander 'Pink Beauty'): This plant produces bright pink blooms and can grow up to 20 feet tall.
  • 'Petite Salmon' (Nerium oleander 'Petite Salmon': This dwarf variety only reaches around 4 to 6 feet tall and wide, and it sports salmon pink blooms.
  • 'Hawaii' (Nerium oleander 'Hawaii'): This variety has pink flowers with yellow throats and grows around 10 to 18 feet tall.