Red-tip photinia (Photinia x fraseri), hardy in U.S. Department of Agriculture plant hardiness zones 7 to 9, is a hybrid shrub highly prized for the coppery red flush it puts out each spring. It’s popularity led to overplanting and the onset of entomosporium leaf spot, a common fungal disease in the plant. Signs of the disease include small, red spots on the tops and undersides of new leaves while older leaves have brown or gray spots with purplish rings. The disease causes leaf drop and eventually death of the plant if left untreated. If caught early, however, it can be controlled with a fungicide.
Rake all leaves that fell from the red-tip photinia. Place those leaves in a trash bag for disposal.
Spread a 2- to 4-inch layer of fresh mulch around the base of the shrub, covering the ground completely. Mulch traps missed leaves, and fresh mulch reduces the risk of spreading the disease.
Put on a long-sleeved shirt, long pants, socks, shoes and rubber gloves. Mix 3/4 fluid ounce, or 1 1/2 tablespoons, of a tebuconazole-based fungicide with 1 gallon of water in a pump-style, pressurized sprayer. Secure the sprayer's lid on the sprayer, and shake the spray until its contents are mixed. Pressurize the sprayer by pumping it. Continue to wear protective clothing when using the fungicide, even in its diluted form.
Adjust the sprayer's nozzle to a narrow pattern that will prevent overspray onto nearby plants. Spray the entire shrub, coating new stem growth, leaf petioles and tops and undersides of all leaves until they are covered but not dripping the fungicide. After the spray dries completely, it is rainproof.
Repeat the fungicide application every seven to 14 days for a total of three applications per growing season. Do not apply the spray when the weather is hot and dry; wait for conditions to change even if it is outside the seven- to 14-day period.