In the 1990s, a plant disease lethal to oleanders was discovered in southern California. Dubbed oleander leaf scorch, this malady is caused by the bacterium Xylella fastidiosa, which is a different strain of the species that causes almond leaf scorch and Pierce's disease in grapevines. Symptoms of oleander leaf scorch, which initially include the drooping and yellowing of leaves on one or more branches, are often mistakenly believed to be brought on by drought. However, shrubs suffering from the disease will not recover when watered since the presence of bacteria limit the flow of water. Instead, the symptoms spread to more branches and the plant eventually dies, usually within 3 to 5 years of the earliest signs of disease.