Photinia leaf spot is a fungus that discolors and destroys plant leaves in the cool, wet elements of spring and fall.
Photinia leaf spot commonly occurs on southern landscape plants, especially the red tip photinia shrub. Additional host plants include Indian hawthorn shrubs, loquat trees, flowering, and fruiting pear plants, and hawthorn and firethorn shrubs.
Photinia leaf spot fungi rest on trees during winter, waiting for the damp elements of spring to arrive. An infection starts with small, black dots on leaves that can be difficult to see. Within a few weeks, symptoms become more pronounced. The dots grow and turn a brownish-gray color with red outlines. The disease remains persistent throughout spring, resulting in a thin, frayed canopy and premature leaf drop.
Infected trees and shrubs will need special care and maintenance to help sustain their strength. Keep the plant’s bed free of disease-causing fungi by raking fallen leaves and adding a two to four-inch layer of mulch in spring. During dry periods, thoroughly water the plant, taking extra care not to wet foliage and promote the spread of the disease. When spring or fall rain subsides, you can prune and dispose of infected leaves. Also, avoid planting photinia in deep shade locations, as the disease will be more severe by being placed in a cooler area. If your tree or shrub appears to be severely damaged, talk to a professional arborist to learn more about fungicide treatments or to get ideas about resistant plants to use as replacements.