Brown Leaves on a Magnolia Tree

Identification

• Magnolia trees are susceptible to oleander leaf scorch, also referred to as bacterial leaf scorch, caused by Xylella fastidiosa. The bacteria primarily spreads by insects like the sharpshooters that feed on water- and nutrient-conducting tissues of plants and transmit disease.

Damage

• The disease is characterized by the yellowing of foliage in certain areas of the tree. With disease progression, the foliage margins turn deep yellow or brown and die. More and more branches are affected and the entire tree eventually dies. Symptoms are more rapid and pronounced during hot weather.

Management

• Oleander leaf scorch is a fatal disease with no cure. Affected trees die within three to five years of symptom onset. Plant resistant varieties and remove dying plants early to minimize spread of bacteria to other landscape plants. The use of insecticides to control insect vectors is ineffectual in disease control.