Michelle Grabowski, UMN Extension Educator
M.Grabowski, UMN Extension
Photo 1: Gray Mold on Geranium
Gray Mold is a common disease of flowers and even some vegetables. The fungus Botrytis cinerea
is the pathogen that causes gray mold. This fungus thrives in wet weather. Recent rains have resulted in increased sightings of gray mold. Gardeners should look for brown spots on leaves with concentric brown rings like a bull's eye. Flowers can be blighted by gray mold at any stage. Brown blossoms or petals can all be caused by gray mold. A fine fuzzy gray mold can be seen on infected plant parts when moisture sits on the plants. Early morning is a good time to check for this pathogen as dew often encourages the fungus to produce spores.
Read more about gray mold.