Each year many growers produce a large quantity of their perennials for summer and fall sales in outdoor production sites.  There are many advantages to producing plants outside; however, in some situations certain insect pests can cause serious damage to ornamental crops.  Leafhoppers are commonly observed in outside production areas and have been known to cause serious injury to crops. They feed on a wide variety of herbaceous perennials including Anemone, Aster, Bellis, Campanula, Chrysanthemum, Coreopsis, Delphinium, Echinacea, Gaillardia, Liatris, Phlox, Rudbeckia, Salvia, Scabiosa  and Veronica to name a few.

There are several pathogens (Erysiphe, Leveillula, Microsphaera, Podosphaera, and Spaerotheca) that cause powdery mildew diseases. These pathogens are host specific, meaning that the pathogen that infects one type of plant is usually different from the mildew that attacks another. Powdery mildew attacks a great number of bedding plants, perennials, and woody ornamentals. Powdery mildew usually does not result in plant mortality, but does reduce a plant’s performance, affects plant quality, and greatly reduces the aesthetic appeal of infected ornamentals.