The term “fairy ring” typically refers to the visual appearance of mushrooms emerged in a circular pattern in a grass lawn, pasture, or meadow. Fairy ring symptoms in turfgrass stands are categorized as Type I (wilted, necrotic turf), Type II (dark green, stimulated turf), and Type III (basidiocarps present). A visual rating system was devised to assist researchers and practitioners with a numerical method to quantify the degree of severity of fairy ring symptoms at a turf site. Therefore, the Fairy Ring Severity Index is based on a 1 to 9 scale, where 1 indicates no fairy ring symptoms present, 2 through 5 indicates the low to high range for Type II symptoms, and 6 through 9 indicates the low to high range for Type I symptoms. For Type III symptoms, the number of mushrooms, toadstools, or puffballs present could be counted if that information is needed or helpful. In experimental research plots, the Fairy Ring Severity Index is a better method for evaluating and comparing fairy ring symptoms vs. using a percent plot area affected estimate.