The oleander is a very common landscape plant in Charlotte County. This evergreen plant does provide substantial blooming power and is a useful subject for hedges and as specimen plants. Right up front, keep in mind that oleanders are poisonous. As a matter of fact, all parts of oleanders are poisonous and should be planted in areas where direct contact with people will be limited — especially children and curious pets. On the flip side, oleanders are very versatile and adaptable plants with beautiful blooms and eye appeal.
Oleanders are great subjects for sunny areas. These plants are also highly drought tolerant and are excellent selections for seaside plantings where they can be protected from salt spray. Oleanders are great for privacy screens or managed hedges, and even take well to container culture. While oleanders require regular watering during establishment, they are able to take droughty conditions better than many plants. Hand-in-hand, these landscape subjects have low fertilizer needs and established plants actually have little to no supplemental fertilizer requirements.
With some oleanders growing to 15-feet tall, regular training and maintenance pruning will help keep optimal appearance and flowering. Wear gloves and perhaps goggles to avoid contact with the toxic properties of the plant. Young oleanders may develop excessive “suckers” or water sprouts that can affect the overall appearance of the plants. These excessive, unproductive growths can inhibit flowering and should be removed. Removing all old flower heads will also increase flowering.
Oleanders offer several forms to choose from including tree types, shrubs, and groundcovers. Many popular cultivars are available in garden centers including “Calypso” with single, cherry red flowers, and “Compte Barthelemy” with double red flowers. “Mrs. Roeding” sports double pink flowers; while “Sister Agnes” is noted for single pure white flowers. For some very different colors try “Isle of Capri,” with single, light yellow flowers; or “Hawaii,” which produces displays of single salmon-pink flowers with yellow throats. There are dwarf cultivars including “Petite Pink” and “Petite Salmon,” which fit well with small scale landscapes and container gardens. To add another twist, try “Variegata” and “Variegatum Plenum,” which have variegated leaves.
Oleanders are generally pest-free with the exception of the insidious oleander caterpillar. This orange and black moth larva is probably the most common pest of oleander referred to our office for identification. The moth is truly beautiful and easy to identify – purple/blue-black wings and body covered with white dots topped off with a red-tipped abdomen. Common in March, July and December, the adult female moth lays up to 75 orange eggs. The resulting caterpillars can literally defoliate this shrub making it an eyesore. Damaged shrubs will grow back however, but repeated defoliations may weaken the shrub. The caterpillars can be managed when small with the biological control, Bacillus thuringensis or Bt available at most garden centers. Used according to label instructions, this least-toxic material affects only caterpillars. Predatory stink bugs will also take their share of oleander caterpillars, as will a variety of other predators and parasites.
It is worth repeating — the oleander is considered a toxic plant capable of poisoning or killing both humans and livestock. Symptoms of poisoning from consumption of leaves includes severe gastroenteritis, diarrhea, abdominal pain, sweating and weakness. Heart rate is also affected. If ingestion is suspected, immediately contact a physician, hospital or poison control center. To prevent poisonings, plant oleander at sites in your landscape where people will not come in direct contact. Parents should avoid planting oleander in their landscapes where small children could accidentally consume the plant. Never burn this plant when disposing of pruned branches! The airborne oils may cause respiratory problems from inhaling the smoke. Also, keep pets and livestock away from this plant. Oleanders do not have to be barred from all landscapes, but education as to common sense precautions and plant placements will limit the danger of poisoning.
In spite of its cautions, the oleander is a Florida-Friendly Landscaping recommended plant suitable for planting in our area! For more information on flowering shrubs (and poisonous plants), or to ask a question, please visit www.facebook.com/CharlotteMGLifeline.
Ralph E. Mitchell is the Director/Horticulture Agent for the UF/IFAS Charlotte County Extension Service. He can be reached at 941-764-4344 or firstname.lastname@example.org.