Do you have black tar spots on your siding?

Have you ever walked around your house and seen little black spots on your siding?  Maybe you tried to wipe them off but found that they wouldn’t come off. Or if you scraped them off they still left a black stain.   

What are these spots and where did they come from?

These little black spots are the byproduct of an organism called Artillery Fungus.  This fungus earned its name, “Artillery” due to its ability to shoot those black spores 10-20ft in the air. This is why they can be found so high up on the siding.

Where does this fungus come from?

This fungus thrives off of wood decay. A lot of dead wood is processed into small wood chips, colored and packaged into individual bags commonly known as mulch.  The more moist the mulch stays the greater ability the fungus has to grow. 


Will these spots come off when I get my house washed?


The house washing process has little to no effect on these spots.  Even when higher pressure is used.  The most effective way is to scrape them off but even then, they leave a black stain behind.


What should I do to prevent further growth of this fungus?


Artillery fungus thrives off of the wet decaying wood.  Places in the shade that get regularly watered with sprinklers that see little to no sun can be a breeding ground for the fungus.  You can use a different kind of ground covering such as stone or artificial mulch made from rubber.