Powdery Mildew of Ornamentals
Author(s) M. F. Heimann, W. R. Stevenson, G. L. Worf
Powdery mildew of ornamentals is a fungal disease encountered by many Wisconsin gardeners every year. Diverse fungi cause the disease and its signature symptom, a powdery growth, on a wide range of ornamental plants€”annuals and perennials, herbaceous and woody.
Typical hosts include birch, calendula, chrysanthemum, cosmos, dahlia, daisy (shasta), delphinium, lilac, oak, rose, phlox, and zinnia. If diagnosed early, powdery mildew can be controlled. Thus, it is important to know how to diagnose powdery mildew, how to recognize the factors that increase its severity, and how to control it (4 pages).