University of Maryland Extension

The Fungus Among Us

Carolyn Puckett
Pseudoinonotus dryadeus

With all the rain we have been having, expect some fungi to suddenly appear in your landscape. Below we have identified some common summer fungi and slime molds.

Dog vomit fungus: This is a type of fungus or slime mold that commonly grows in mulch during warm periods with either high humidity or rainfall. It begins as a yellow or orange mass but eventually dries to a white powder. Slime molds are not harmful. Dig it up and dispose of it if you wish. There is no chemical control. For more information see:

Fairy rings: These fungi can either cause dead circles in turf or darkened circles. They are more common on droughty or poorly nourished sites. There is no effective control. For more information see:

Puffball mushroom: Puffballs are the fruiting structure of a kind of fungi. They are not harmful and no control is needed. For more information see

Powdery mildew: White splotches on leaf surfaces, young stems or flowers are likely powdery mildew. Infection is rarely lethal, but does cause leaf yellowing and browning, leaf distortion, premature leaf drop, and blemished or aborted flowers and slower-than -normal growth. Young plants grown in heavy shade are the most seriously affected by this disease. Pruning for better air circulation and selecting resistant varieties are the best controls. For more information see

Turf brown patch: Brown patch affects all turfgrass, especially tall fescue and perennial rye. It is a common summertime disease of cool-season turfgrasses in Maryland. Symptoms include circular yellow-brown patches of thinned turf. On individual blades, elongated lesions bordered above and below by tan or chocolate-brown bands. See more at:

Septoria on rudbeckia: There are a number of diseases that affect the leaves of the popular black-eyed Susans. One common disease is septoria, which causes dark brown leaf spots. Try to avoid wetting the leaves . For a description of common rudbeckia diseases see:

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