Question: Are there any new developments regarding oleander leaf scorch?
Answer: This devastating disease is being spread throughout Southern California by a type of leafhopper known as the glassy-winged sharpshooter, which punctures the oleander's soft, new growth as it feeds, injecting bacterium.
Symptoms of baterial scorch include leaf-tip dieback and scorched yellow, light brown or rust-colored leaf margins, which usually start with one plant section. As the disease progresses, more sections of the plant die.
There is no known cure. An infected plant will probably die within two years.
To control the spread of this disease, the home gardener has several options.
Aggressive pruning appears to substantially delay (but not halt) the disease. Prune at least 1 foot below infected areas. Clean pruning tools between plants with a solution of 1 part bleach to 10 parts water.