Do you have ugly black spots on your house siding? Over the years, I have notice more and more black spots. Not matter how hard I try, those darn spots won’t come off. Guess what is causing them? Your mulch. Read on how to prevent them.
What are these black spots on your house siding?
According to Dr. Donald D. Davis of Penn State:
“The artillery fungus is a white-rotting, wood-decay fungus that likes to live on moist landscape mulch. It is in the genus Sphaerobolus (Greek for “sphere thrower”) and is very common across the USA, especially in the East, as well as many other parts of the world.”
Those darn spores love the northern side of a home and light color siding. (My siding is a creme color.) Those spores are impossible to get off.
Most people buy shredded mulch which retains moisture. It created a fertile ground for the fungus.
Dr. Davis’ FAQ, fellow fungus-ridden homeowners suggestion how to remove the spores. Some of the suggestions included minted mouthwash and Mr. Clean Magic Eraser.
Oh, and I am dreading trying to remove these spores.
How to avoid the fungus
In a study conducted by Dr. Davis, 27 mulches were studied as to the amount of spores they produced. The team concluded that large bark pine nuggets, cypress mulch or 100% mushroom substrate supported less artillery fungus. But despite these finding, the team further concluded ALL mulches within a three to four year period would become susceptible to the fungus.
In laboratory studies, licorice root inhibited the fungus. The authors of the study further noted that the fungus may not grow on fresh pine straw.
Bottom Line
Get rid of your mulch and replace it with landscape fabric and stone. Alternatively, use low-growing plant groundcovers as underplantings for foundation shrubs such as liriope, pachysandra, sweet woodruff and hardy ginger in the shade. For sunnier spots, use creeping sedum, leadwort, vinca and liriope in sunnier spots. Be sure to use plants that are deer resistant in your area otherwise, you will be creating another headache for yourself.
We tried the old elbow grease method and it didn’t work. Next step is the old minted mouth wash idea.
Join the Conversation
- Do you have those dreaded black spots on your siding?
- Do you have a way to get rid of them?
James Paulson says
Great suggestions and thanks for sharing this!
Jack White says
Those black spots are really starting to hit me pretty hard on my house. I ignored them for a bit, which wasn’t a good move. I well use your suggestion of replacing with fabric. This should be able to prevent this from happening again.
Kathy says
We have a power washer that will take the specks off as long as I patiently go back and forth on each individual spot. Very few left a brownish tint beneath. I’m not finished with the job yet. I also tried using a magic eraser and I could feel that it loosened a few dots. I’m going to try the blue minty mouthwash along with the power washer next time because I can’t reach up on my house as high as some of these dots go. They say the fungus can splash up to 20 feet! It’s only on the east side of our light colored house and there is mulch there along with a window air conditioner dripping. That’s bad 😒
Jessica Robinson says
Thanks for sharing this! I wasn’t sure why these spots are appearing and how should I clean them. Greetings! xx
Bélise says
Like you, I have tons of those black spots on my house siding. I had no idea that the cause of them was the mulch I use. Thanks for this informative article! I’ll definitely get rid of my mulch and try landscape fabric or plant ground covers instead.
Steve says
Well, the better way to fix this is to build structures that avoid moisture problems. With little or no moisture or damp problem, those mossy things wont grow.