Buckeye Yard and Garden onLine

Gary Gao asked BYGLers about the possible occurrence of the shotgun fungus inside a building. Black dots found on the interior walls of an office looked exactly like the black dots produced by shotgun or artillery fungus (Sphaerobolus spp.). The black dots inside of the office were associated with a house plant on a desk. Over the years, there have been reports of shotgun fungus or artillery fungus on house sidings/walls and cars in BYGL. It is quite rare to see shotgun fungus inside a building. Joe Boggs said that he had seen a case of shotgun fungus in a shopping mall. The fungus had shot numerous spore masses creating black dots on walls. In this case the fungus was associated with the interior plantings. The interiorscape managers had altered their mulch around the base of the plantings. Prior to the spotting on the walls, a new mulch that had been added to the interiorscape was a standard hardwood mulch normally used on the exterior of the building, the type of mulch where shot gun fungus thrives. Apparently, in Gary's case, the shot gun fungus was growing in the organic materials in the pot of the house plant.

These black dots are extremely difficult to remove. This fungus is also poorly understood. There is a good website by Dr. Don Davis of Penn State University. The website is entitled "Artillery Fungus ‑ Frequently Asked Questions (FAQ)" at: http://www.personal.psu.edu/faculty/d/d/ddd2/. Hard scrubbing with rubbing alcohol did the job in this case since the black dots were discovered very early. There are other cleaning suggestions on Dr. Davis' website. For more information, refer to OSU Extension FactSheet, HYG# 3304-98, "Control of Nuisance and Detrimental Molds (Fungi) in Mulches and Composts."

For more information, see:

• Control of Nuisance and Detrimental Molds (Fungi) in Mulches and Composts
• Shotgun fungus information from Dr. Don Davis at Penn State
• Cornell’s Fact Sheet on Shotgun Fungus