Treating Fungus on Outdoor Ficus Hedge

Mark's outdoor ficus hedge in Florida is losing leaves with white halo lesions, likely fungus. He wants treatment to restore growth in spring.

Expert Answer: Consult a local garden center for appropriate fungicides and follow safety instructions. For a non-chemical option, spray 2 tablespoons baking soda per gallon of water twice weekly. Baking soda creates an alkaline environment that inhibits fungus (which prefers acidity). This method has worked for blackspot on roses. Indoors, generic Lysol spray twice weekly also works, but outdoors it's costly.