Answer: Some of the newer zinnia varieties have been developed with mildew resistance in mind. The "Pinwheel" series does very well in this regard, and the "Profusions" have done especially well for me in terms of mildew. Another possibility, although the looser plants and smaller flowers provide an entirely different look, are the "Starbrights." To try to keep mildew at bay, avoid wetting the foliage when you water, especially at night, plant the plants far enough apart so they enjoy good air circulation, and plant them in a spot with good air flow. It helps to keep the plants adequately watered so they are not water stressed. Healthier plants seem to perform better over all, including in resistance to mildew.
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