Ovulinia Petal Blight

You'll see ovulinia petal blight on azaleas and rhododendrons as small water-soaked spots on flowers that rapidly spread, causing flower rot. Infected flowers first show small spots about one millimeter in diameter. Remove and destroy infected flowers promptly. This disease favors cool, wet conditions during bloom. Improve air circulation and reduce leaf wetness to prevent infection. This blight is most damaging during cool, wet springs when flower and shoot development is rapid. Monitor plants closely during vulnerable periods.

Remove and destroy infected flowers. The practice of "deadheading" can be helpful. Remove affected tissue promptly, cutting into healthy wood. Improve air circulation by thinning dense growth and avoid overhead watering during susceptible periods. Preventive fungicide applications may help where the problem recurs annually.