Pest of the Week - Artillery Fungus

Have you ever noticed tiny black spots on the siding of your house or on your car?  The spots may be caused by artillery fungus Sphaerobolus spp.  The fungus produces very small fruiting structures that contain a small dark bodied spore.  Pressure within the fruiting structure caused by the accumulation of nutrients and water "shoots" the spore toward any light source.

Closeup of the artillery fungus peridiole on automobile paint
Joey Williamson, HGIC, Clemson Extension

Magnolia foliage covered with artillery fungus peridioles
Holly Thornton, Univ. of Georgia, Extension Plant Pathology

A lot wood mulches are suitable for the growth of Artillery fungi. This decay organism propagate itself by shooting spore bodies a long distance when the fruiting structure of the fungus ruptures. When using wood mulch be sure to use only a think layer of mulch near homes, decks, and parking areas to avoid damage from the spore bodies, which are very difficult to remove.


Additional Information

Artillery Fungus Fact Sheet - Cornell University

Fact Sheet 5103 - Artillery Fungus - University of Maine

Artillery Fungus - FAQ - Dr. Donald D. Davis, Penn State -Penn State University