Description

• White oleanders bloom from summer through mid-fall with large clusters of blooms, and sometimes double blooms. Some of the double bloom varieties are scented. Leaves are long and slender, smooth and leathery. The bark on stems range from pale green to light gray in color. Most white oleanders grow between 8 and 12 feet tall, but a few dwarf cultivars stay in the 3 to 5 foot range. Flowering occurs on new growth and oleanders exhibit about 1 to 2 feet of new growth each year.
  
  

Planting Conditions

• While oleanders prefer soil pH in the 6.5 to 7.5 range; they do well in all but highly alkaline soil conditions, as long as the earth is well drained. Plants do well with an occasional deep watering, but typically do not like standing water. Fertilizers and additional nutrients are not necessary. Oleanders thrive in full sun and can take reflective heat from walls with southern exposures. Partial shade conditions usually lead to oleander plants that are lean and lanky.
  
  

Pruning

• Early spring is the best time to prune old growth from white oleanders. Those that survived cold weather can be pruned aggressively to remove damaged twigs. Oleanders regrow rapidly from the base of the plant after pruning.
  
  

Problems

• A fungus disease called botryosphaeria dieback causes branches to turn a blackish-brown color as they die. Oleanders are especially prone to the fungal disease after drought stress or after having been frozen in frigid temperatures. Pruning back to good, clean wood on twigs relieves oleanders of dieback. The main pest for oleanders is a caterpillar of the same name. Orange-red and 2 inches long, just a few can lay waste to oleander leaves in a matter of days. The plants will recover, but may become susceptible to attack by other insects, such as aphids, while healing.
  
  

Danger

• All parts of oleanders are poisonous to people and livestock. Consuming a single leaf is "lethal enough to kill a 150-lb. adult," according to Arizona State University. Clemson Cooperative Extension recounts that "children have been poisoned by using the twigs as whistles." Abdominal pains, profuse sweating, weakness and diarrhea occur within a few hours after ingestion. Some people even have skin reactions simply from touching the plant. Oils containing toxins are also released if the plant is burned, with the possibility of serious reactions.