Leaf spot (Diplocarpon)

Red tip photinia (Photinia davidiana) develops leaf spots from Diplocarpon fungi, especially on young vulnerable growth. Plant in full sun, space for air circulation, remove fallen leaves, and avoid overhead irrigation or summer pruning. Apply fungicides to emerging shoots in early spring if disease recurs.

Leaf spot and blotch diseases are primarily cosmetic on established plants, though repeated years of heavy infection can weaken them. Rake up and remove fallen leaves to reduce the spore load going into the next season. Avoid overhead watering that splashes spores from the ground onto lower leaves. If the problem is severe, protective fungicide sprays during spring leaf emergence can help, but sanitation does more than chemistry for most leaf spots.