When to plant oleander?

When did oleanders, natives of Mediterranean climates, arrive in the United States? We turn to the International Oleander Society (established in 1967) to learn that Texas played a key part in the story: “The first oleanders came to subtropical Galveston in 1841. Joseph Osterman, a prominent merchant, brought them aboard his sailing ship from Jamaica to his wife and to his sister-in-law, Mrs. Isadore Dyer. Mrs. Dyer found them easy to cultivate and gave them to her friends and neighbors. The familiar double pink variety that she grew has been named for her.”

The rest is more history.

Above: Oleanders are evergreen, a further benefit, and their leathery leaves can provide a calming backdrop against a fence or as an anchor at the back of a border. Photograph byAlvesgasparvia Wikimedia.

“Due to the preserving layers of volcanic ash from the eruption of Mount Vesuvius, we know that oleanders were also grown in the gardens of Pompeii,” according to the International Oleander Society. “They were the plant most often painted on Pompeian murals (circa 79 AD) and were usually found represented in informal settings as background plants or mass plantings in the unique, traditional garden wall paintings whereby the Pompeians created the illusion that their gardens extended far into the countryside.”

Cheat Sheet

  • For a cold-hardy cultivar that can survive winters in USDA Zone 7, consider Nerium oleander ‘Hardy Pink’ with candy-colored flowers.
  • For double flowers, consider N. oleander ‘Mrs. Lucille Hutchings’.
  • In colder climates, keep oleander in pots and move the plants to a protected spot or indoors in winter months.
  • Drought resistant, oleander is frequently planted along highways and thoroughfares as a screening plant and windbreak.

Above: Oleander’s leaves closely resemble the shape, color, and texture of foliage on olive trees. Photograph by Dalgial via Wikimedia.

Keep It Alive

  • Oleander prefers full sun but will tolerate some shade; well-drained soil is a requirement.
  • Prune in late winter while dormant; oleander flowers on new growth.
  • Train dwarf varieties to grow as a low hedge (which will need to be shaped at least twice a year). Consider compact ‘White Sands’ for a variety with white flowers.

See more growing tips in Oleander: A Field Guide to Planting, Care & Design in our curated design guides to Shrubs 101. Read more:

  • True Colors: 9 Best Shrubs for Fall Foliage
  • Ask the Expert: Will a ‘Poisonous’ Plant Really Kill Your Pet?
  • Everything You Need to Know About Shrubs
  • Pittosporum: A Field Guide to Planting, Care & Design

How Toxic Is Oleander to Humans?

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Oleander (Nerium oleander) is a striking evergreen shrub characterized by long, lance-shaped leaves, a resilient disposition and fragrant blooms in shades of reds, pinks, yellow and white. A native of southwestern Europe and East Asia, oleander can be found growing in sunny sites in U.S. Department of Agriculture plant hardiness zones 8 to 11. While the shrub is beautiful and sounds like a gardener’s dream, it’s also deadly: Ingesting a single leaf can kill an adult. Due to the plant’s extreme toxicity, oleander may not be a suitable shrub for households with small children or pets, and the risk may be too great even in an adults-only home.

All Parts Are Toxic

Oleanders contain two extremely toxic cardiac glycosides, oleandroside and nerioside. These toxic components exist in all parts of the plant, from the leaves to the branches, seeds, flowers and even the flower nectar. Toxins are effective whether the plant is fresh or dry, and honey made from the flowers is also poisonous.

Ingestion May Be Fatal

Ingesting even a very small piece of the plant may be fatal. People have died from using oleander branches as skewers for meat. Also, children have been poisoned from chewing leaves and sucking nectar from blossoms. Poisoning symptoms may include severe stomach pain, diarrhea, vomiting, nausea, weakness, dizziness and irregular heartbeat. Also, pupils may appear dilated. In the worst case scenario, respiratory paralysis, coma and death occur. Contact your health care provider or call the American Association of Poison Control Centers’ free, confidential Poison Help line at 800-222-1222 if you suspect someone has been poisoned by oleander.

Pets Are at Risk

Oleander is also extremely toxic to cats, dogs and horses. Poisoning symptoms in pets may include colic, sweating, incoordination, difficulty breathing or shallow breathing, and diarrhea, which may turn bloody. Pets may also suffer muscle tremors and be unable to stand up. They may die from cardiac failure. If your pet ingests oleander, contact your veterinarian, or call the ASPCA Animal Poison Control Center at 888-426-4435. The ASPCA may charge a $65 consultation fee.

Protect Yourself When Handling

Simply touching an oleander plant can cause skin irritation, particularly if you come into contact with the plant sap. If you are cultivating an oleander, wear gloves when you prune the shrub, and wash your hands well afterward. Disinfect your pruning shears by soaking your tools in a solution that is equal parts alcohol and water for five minutes. Rinse with water and air dry. Do not burn oleander clippings, as the smoke can irritate the eyes and lungs. Do not compost oleander; instead, secure clippings in a bag and throw away.

PMC

DISCUSSION

Most of the plants, including foxglove and oleander, have been identified as containing cardiac glycosides and these are oleandrin, oleandroside, nerioside, digitoxigenin, thevetin, and thevetoxin. The cardiac glycosides in oleander produce more gastrointestinal effects than those in digoxin, and the symptoms range from nausea and vomiting to cramping and bloody diarrhea. Also, it causes irritation to the mucosal membranes, resulting in burning around the mouth and increased salivation. Confusion, dizziness, drowsiness, weakness, visual disturbances, and mydriasis are central nervous system manifestations of toxicity.

The most serious side effects of oleander poisoning are cardiac abnormalities, including various ventricular dysrhythmias, tachyarrhythmias, bradycardia, and heart block. Electrocardiography often reveals an increased PR interval, a decreased QRS-T interval, and T wave flattening or inversion. It is thought that these clinical manifestations are the result of both increased vagotonia and direct cardiac glycoside toxicity.

The treatment of oleander poisoning is empirically based on the treatment of digitalis-glycoside toxicity and consists of supporting the patient hemodynamically. This may include administering atropine for severe bradycardia; using phenytoin or lidocaine hydrochloride to control dysrhythmias; placing a temporary venous pacemaker; or electrical counter shock and administering digoxin-specific Fab antibody fragments (Digibind).

Other treatment methods are aimed at removing the toxic substance from the stomach by emesis. Special concern must be given to a patient with bradycardia before emesis is induced because of the possibility of a vagal reaction and worsening of the bradycardia. Unabsorbed glycosides may be bound to some extent, depending on the particular glycoside, by various binding agents in the gut. These agents theoretically should be more effective in absorbing less polar glycosides, such as digitoxin, than the more polar glycosides like digoxin (for example, cholestyramine resin and colestipol). The use of these agents is not thought to have substantial value in the treatment of advanced toxicity, and they were not used in our patient. Activated charcoal has been shown to be useful in preventing further absorption of the cardiac glycosides by interruption of the enterohepatic circulation of the glycoside, but it was not used in our patient because she was brought after 15 hours of ingestion of the toxin and due to the unknown status about the enterohepatic circulation of oleander’s glycosides.

Yellow Oleander Care: Uses For Yellow Oleander In The Landscape

Yellow oleander trees (Thevetia peruviana) sound as if they should be closely related to oleander, (genus Nerium) but they aren’t. Both are members of the Dogbane family, but they reside in different genera and are very different plants. Read on for yellow oleander information and tips on yellow oleander care.

Yellow Oleander Information

Yellow oleander trees are so small that many consider them large bushes. Yellow oleander information suggests that these evergreen plants rarely get over 10 feet when cultivated, although they can get to 20 feet in the wild.

The flower of yellow oleander looks like a narrow tube that flares out at the tip into five petals, twisted into a spiral shape. They are fragrant, about 2 inches long and grow in clusters. A mechanism inside the throat of the flowers helps with pollination. It coats insects

coming for the sweet nectar with pollen, making sure that they will transfer pollen to the next flower.

Yellow oleander trees’ thick fruit has four sides and changes colors as it matures. The fruit starts out green, then turns a lipstick red, but finally matures into a dull black. The stone inside is brown and smooth and makes nice necklaces.

Uses for Yellow Oleander

Yellow oleander trees grow in savannahs and riparian areas in their native range in Africa. They can become invasive if grown in open regions, and the trees have been listed as noxious weeds in South Africa.

In other countries, the uses for yellow oleander are largely ornamental. In the United States, the tree is cultivated as a garden plant, despite its toxicity. Is yellow oleander poisonous? Yes, it is. Every part of the plant is poisonous.

Yellow Oleander Care

Many gardeners choose to grow yellow oleander in spite of its toxicity, seduced by the plant’s luxurious, tropical look and long-lasting blossoms. If you want to grow this plant, it’s nice to know that yellow oleander care is not difficult nor time consuming. Just be cautious about growing it around small children and pets.

Plant yellow oleander trees in part or full sun, since they like heat. The trees do best in well-draining soil with lots of organic content, so work in compost before you plant.

You’ll need to water these plants regularly. Pruning and litter cleanup (wear gloves) will take a little of your time as well. Generally, however, these are low-maintenance plants.

Dwarf Oleander Red

Nerium Oleander’Petite Red’

  • Red Flower
  • Evergreen blooming shrub
  • Periodic blooms throughout the year
  • Low-maintenance, easy care plant
  • Attracts hummingbirds and butterflies
  • Excellent as an informal hedge

Dwarf Oleander Red features beautiful red flowers that bloom periodically throughout the year, so planting this Mediterranean native is an excellent way to add a bounty of color in the landscape. Since they tend to bloom more during warmer months, they are ideal for growing in our climate. We like to use them as an informal flowering hedge, and they are beautiful planted along property lines or lining a walkway or driveway. We also like to plant them around the patio or as an accent for a garden bed. This Nerium Oleander’Petite’ is often planted on the grounds of banks and commercial properties because they are such low maintenance, easy care plants. If you are looking for a shrub that offers big, colorful rewards with minimal care required, look no further!

These Dwarf Oleanders need little to moderate water once established, and since it is a dwarf variety, they are perfect for smaller gardens. These shrubs prefer to be planted in a sunny location, where they can soak up the sun because they love full sun exposure. Use them in a broad range of garden styles because they can tolerate poor soils too. Suitable for Mediterranean gardens, city gardens, cottage gardens, wherever you plant them is also sure to attract butterflies and hummingbirds!

Moon Valley Nurseries grows Nerium Oleander in our local climate, and we grow from our premium quality specimens. Moon Valley Nurseries can assure the quality of everything we grow here. Visit and of our nurseries throughout the Southwest and see the difference of the trees, shrubs, and other plants that we grow in our local climate. A Moon Valley Nurseries pro will be glad to help you handpick just what you need for your landscaping goals.

Flowers and buds of a double-flowered, white oleander (Nerium oleander).
Photo by Karen Russ, ©2008 HGIC, Clemson Extension

Oleanders (Nerium oleander) are distinctive and beautiful, large, flowering shrubs that thrive with little care. They are very heat and drought-tolerant once established, and will grow especially well in seaside gardens, tolerating salt spray and wind. Oleanders generally grow best in the coastal areas of South Carolina. Most cultivars will be damaged or killed by winter cold in the Midlands and Piedmont.

Mature Height/Spread

Most cultivars will grow to 8 to 12 feet tall and almost as wide. In some protected areas mature plants may reach up to 20 feet tall. Some dwarf cultivars stay as low as 3 to 5 feet.

Growth Rate

Oleanders grow at a medium to rapid pace, producing 1 to 2 feet or more of growth per year. Established plants that have been damaged by cold will regrow very quickly from the base.

Flowers and buds of a single-flowered, light pink oleander (Nerium oleander).
Photo by Joey Williamson, ©2013 HGIC, Clemson Extension

Ornamental Features

Oleanders are usually very large, mounded shrubs that take up considerable space in the landscape. Their quick growth rate and thick multi-stemmed habit makes them ideal for use as a screen or informal hedge.

Oleanders flower from early summer until mid-autumn with large clusters of 2-inch single or double blossoms. Colors range from pure white through pale-yellow, peach, salmon and pink to deep burgundy red. Some varieties (mostly doubles) are fragrant.

The leaves are smooth, dark green, thick and leathery. They are long and narrow, usually between 4 and 6 inches long and an inch or less wide. The dwarf cultivars also have smaller leaves. Leaves generally grow in whorls.

Landscape Use

Oleanders grow best in full sun and will tolerate even reflected heat from a south or west wall. They will tolerate partial shade, but may have a lanky, open shape.

Oleander (Nerium oleander) leaves and branch habit.
Photo by Karen Russ, ©2008 HGIC, Clemson Extension

Oleanders are tolerant of many different soil types, but must have good drainage. They will not do well in wet areas. Oleanders are very drought-tolerant once established, but respond well to occasional deep watering.

Oleanders can be allowed to grow in their natural large mound form, or they can be trained to a small multi-stemmed tree. Since oleanders bloom in summer on new growth, prune them in the early spring. Oleanders will tolerate quite hard spring pruning to remove cold damaged or overgrown wood. Remove dead flower clusters to encourage longer bloom. Cut stem tips off to encourage branching after the flowers are spent, but avoid cutting too late in the fall, as the new growth may not have enough time to harden before frost.

Most oleanders will survive temperatures down to 15 to 20 °F, although their foliage will be damaged. They are typically listed for growing in USDA zones 8b to 10. Even on the coast, some winter damage may occur each year. If the tops are killed back by cold, they will recover quickly in spring as long as the roots were not damaged.

Warning

Oleander is extremely poisonous*. Eating even small amounts of any part of the plant can make a person or animal severely ill or cause death. Contact of sap with skin may cause irritation. Smoke from burning cuttings can cause severe reactions.

Cold injury on Oleander (Nerium oleander) foliage. New growth has begun in early April.
Photo by Joey Williamson, ©2015 HGIC, Clemson Extension

Problems

Botryosphaeria dieback, caused by the fungus Botryosphaeria species causes branches and shoots to die and turn blackish brown. The disease is more likely to occur when plants have been subjected to drought stress or damaged by severe freezes. Prune out all affected branches, making sure that no discolored tissue is left in the cross section.

Oleander caterpillars are the most damaging pest of oleanders.
Photo by Anne W. Gideon, www.insectimages.org

The oleander caterpillar is the most damaging pest of oleanders. Young oleander caterpillars feed in groups, skeletonizing young shoots. Mature caterpillars are highly visible – up to 2 inches long, orange-red with black tufts of hair. A severe infestation can strip a plant bare of leaves in a few days. While even total defoliation will not kill an established plant, it will weaken it, and may make it more susceptible to other pests. Aphids, mealybugs, and scales may also occasionally be problems.

Varieties

In general, cultivars with thicker, dark green, leathery leaves tend to be hardier to cold. Single flowers usually drop cleanly, while spent double flowers may linger unattractively on the plant. On the other hand, most fragrant oleanders have double flowers. Nurseries often sell oleanders by color rather than by name.

  • ‘Algiers’ grows 5 to 8 feet tall. It is free blooming, with single, dark red flowers.
  • ‘Calypso’ is cold hardy and vigorous, growing 10 to 18 feet tall, with single cherry red flowers.
  • ‘Cardinal Red’ grows 6 feet tall and 10 feet wide and produces single, bright red flowers.
  • ‘Hardy Red’ is the hardiest cultivar, surviving even in some protected locations in the Piedmont, although it may suffer damage in some winters. The plants grow to 8 feet tall with very deep red, single flowers. It may tolerate cold in USDA zone 7b.
  • ‘Hardy Pink’ is similar to ‘Hardy Red’, but with salmon pink flowers. It may tolerate cold in USDA zone 7b.
  • ‘Little Red’ (PP#4836) grows from 3 to 6 feet tall and 3 to 6 feet wide and produces deep red blooms.
  • ‘Matilde Ferrier’ is often sold as ‘Double Yellow’ and is the most commonly available yellow flowered oleander. It grows to above 8 feet tall.
  • ‘Petite Salmon’ and ‘Petite Pink’ are dwarf plants that will stay at 3 to 4 feet if lightly pruned. They are less cold hardy than most oleanders and should only be used in very sheltered areas near the coast.
  • ‘Sealy Pink’ grows 8 or more feet tall and 6 feet wide and blooms with single, soft pink flowers.
  • ‘Sister Agnes’ is hardy and vigorous, growing 10 to 12 feet tall. The large, single, white flowers are self-cleaning. It is often sold simply as ‘White Oleander’.
  • Variegated Twist of pink™ grows to 6 to 8 feet tall and wide, and produces deep pink blooms. The foliage has creamy white variegation on leaf margins.

Oleander Care: Tips For Growing Oleanders In The Garden

Oleander plants (Nerium oleander) are among the most versatile of shrubs, with dozens of uses in southern and coastal landscapes. They tolerate a wide range of conditions, including difficult soil, salt spray, high pH, severe pruning, reflected heat from pavements and walls, and drought. But the one thing they can’t withstand is winter temperatures below 20 degrees Fahrenheit. However, in cooler climates, you can grow an oleander plant in a container and bring it indoors when temperatures drop.

Growing Oleanders in the Garden

The first thing you should know if you want to grow an oleander plant in the garden is that you need to avoid growing oleanders in home landscapes where children and pets play. All parts of oleander shrubs are poisonous and the smoke from burning oleander debris is toxic. Ingesting even a small amount of foliage, flowers or shoots from an oleander plant can

be fatal. Contact with the foliage and flowers can cause severe skin irritations and allergic reactions as well. Always wear long sleeves and gloves when working with the shrub.

Oleanders bloom from spring until the end of summer, producing large clusters of flowers in shades of yellow, white, pink or red at the tips of the stems. They grow and bloom best in full sun, but they will tolerate light shade.

Oleanders are considered hardy in USDA plant hardiness zones 8 through 10, but they are sometimes damaged by frost in zone 8. The shrub usually recovers, even if killed nearly to the ground. Prune and reshape the damaged parts of the shrub to encourage new growth.

How to Care for Oleander

Oleander care is easy and this makes the shrub popular with highway departments. You’ll often see masses of oleander shrubs planted in highway beautification projects where they provide an outstanding display of long-lasting flowers with very little maintenance.

Even in the garden, oleander shrubs require minimal care. Although the shrubs are drought-tolerant, they look their best when they are watered during dry spells. However, take care not to over water them. Yellowing leaves indicate that the plant is getting too much water.

If the soil is poor, feed the plant lightly with a balanced fertilizer during its first spring. Once established, oleander shrubs don’t require routine fertilization.

Pinching out the tips of young stems reduces legginess and encourages the shrub to branch out. Pruning oleanders can also be performed. Prune to remove damaged or diseased limbs any time and prune to shape the shrub in late fall.

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