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Entomosporium Leaf Spot

Entomosporium Leaf Spot

Entomosporium mespili

Fungalalso: Entomosporium, Photinia leaf spot, Fabraea leaf spot

The most common leaf disease of Indian hawthorn, and a frequent problem on red tip photinia, caused by a fungus that spots and drops the leaves. It shows as many small red spots that merge into blotches, and in wet springs and falls it can defoliate a shrub and weaken it over several seasons.

🔎 How to spot it

Look for tiny, round, bright red to maroon spots on both the upper and lower surfaces of young leaves. As spots age they may develop small dark fruiting bodies in gray centers, and on heavily infected leaves they merge into large irregular blotches. Badly spotted leaves yellow and drop, and repeated leaf loss thins the plant.

🥀 Damage it causes

The spotting and especially the leaf drop are the damage: a shrub that loses much of its foliage repeatedly grows poorly, looks bare and unsightly, and is weakened and more vulnerable to other stresses. New, young leaves are the most susceptible, so flushes of growth in spring and fall are when most infection and defoliation happen.

🔬 What causes it

The disease is caused by the fungus Entomosporium mespili. It is splashed from leaf to leaf and plant to plant by water and is most damaging during periods of frequent rain in spring and fall, and where overhead watering keeps the leaves wet. Crowded plantings with poor air movement stay wet longer and develop worse disease. The fungus survives on infected fallen leaves and on the plant. Besides Indian hawthorn it attacks red tip photinia, pear (including Bradford pear), loquat, quince, and pyracantha.

🛡️ Prevent it

The best defense is to plant resistant cultivars (Indian hawthorn selections such as Indian Princess, Blueberry Muffin, Olivia, and Eleanor Tabor are noted as more resistant) in a full-sun site with good spacing for air movement. Water with drip or soaker hoses rather than overhead sprinklers so the leaves stay dry, and rake up and discard fallen diseased leaves, which are a key source of spores.

🧯 If it is already here

Where the disease is established, collect and destroy fallen leaves and improve air flow and watering first. For valuable plantings, a protectant fungicide such as chlorothalonil applied as new growth emerges in spring and repeated on a schedule, roughly every ten days in rainy weather or every two weeks in dry weather, protects the new leaves through the infection period. Spraying without fixing the moisture and sanitation usually gives poor results.

💡 Good to know

Indian hawthorn and red tip photinia are so prone to this disease that in humid regions resistant species or alternative shrubs are often the better long-term choice. Because infection is driven by wet leaves, the simple switch from overhead watering to drip irrigation, plus better spacing, often makes the biggest difference.

🌱 Plants it affects

62 plants in the library can be affected by this problem

Amethyst Falls WisteriaAnjou PearAnnabelle Smooth HydrangeaAnnual VincaArizona Sun Blanket FlowerAroniaAsian PearBartlett PearBecky Shasta DaisyBosc PearBraeburn AppleBrunneraCarolina JessamineCascara SagradaChampagne LoquatCleyeraClimbing HydrangeaCornelian CherryCortland AppleCosmic Crisp AppleCrimson Cherry RhubarbDiabolo NinebarkEarly Amethyst BeautyberryEndless Summer HydrangeaEvergreen HuckleberryFeather Reed GrassFountain GrassFuji AppleGala AppleGateway Joe Pye WeedGoldflame SpireaGoldsturm Black-Eyed SusanGranny Smith AppleHawthornHoneycrisp AppleHummingbird SummersweetIndian HawthornJapanese PierisKobold Blazing StarLily of the ValleyLimelight Panicle HydrangeaLingonberryLynwood Gold ForsythiaMajor Wheeler Trumpet HoneysuckleMcIntosh AppleMedlarMoerheim Beauty SneezeweedNatchez Mock OrangePink Lady ApplePrickly PearQuaking AspenQuinceRed Delicious AppleRegent SaskatoonRoyal Heritage Lenten RoseSalalSheffield Pink Garden MumSnow Queen Oakleaf HydrangeaSpeedwellSugar AppleTennessee Red Valencia PeanutTexas Scarlet Flowering Quince

For educational and informational purposes only. Disease management advice is general guidance drawn from university cooperative extension sources; always identify a problem positively and read and follow the label on any product before use, especially around food crops, children, and pets.