Botrytis Gray Mold

by Josh Gibson, Sarah Williams  & Francesca Peduto Hand

What is it? What to do about it?  ♣  Dig deeper  ♣  Download Fact-sheet pdf


Gray mold, caused by the fungus Botrytis cinerea, is the most common disease of herbaceous ornamentals. It can affect almost every type or variety of floral crop, as well as many other types of plants. Depending on the host and the conditions under which the crop is grown, this disease can either be a common nuisance or an economic disaster. Symptoms may include pre- and post-emergence damping off, leaf spots, flower blights, bud rots, stem cankers, stem and crown rots, cutting rots and in extreme cases, plant death. Proper sanitation and manipulation of the greenhouse environment can successfully reduce the impact of this disease.