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What Are Those Black Spots On The Side Of My Home

A lot of people ask us what those black spots are on the sides of their home. Unfortunately, there are just some things that even we can’t remove when we clean your home.

What we are talking about is Artillery Fungus. These spots originated from the decaying wood mulch you have around your home and are the Sphaerobolus Stellatus spores. During pollination the spores can be shot into the air as high as 20’. If you look, you may even see them on the sides of the gutters. The reason they remain stuck on the home after cleaning is not a problem with our low pressure or SoftWash cleaning process. Attempting to blast them off with high pressure will only damage the surface these sticky little spots are attached to. 

There are companies trying to come up with products to aid in the removal of these black spots and Sea to Summit Pressure Washing has been selected as one of the few contractors in the country to test these products, but we have yet to see an effective and efficient method of removing these problematic spots.

So as you can see, it is not the fault of anyone that cannot remove these spots because they have literally glued themselves to your home.

Below is a reprint of an article written by Gene Austin of the Philadelphia Inquirer that can give you more information about these menacing black spots and how to prevent them.

Reprint of Article By Gene Austin, Philadelphia Inquirer March 3, 2001

If your siding, car, fence or any other surfaces around your house have broken out with a rash of black or dark-brown specks that you are having a problem getting off, you are probably at war with something called artillery fungus.

It has become increasingly common in recent years, according to experts who have been seeking ways to control and eradicate it.

Artillery fungus, also called shotgun fungus or Sphaerobolus Stellatus, usually originates in wood mulch that is used around shrubs, flowers and other plants. Wet, rotting mulch breeds small mushrooms that shoot off spores for distances of up to 20 feet. The spores, which are sometimes mistaken for insect waste or bits of tar, cling tenaciously to surfaces such as house siding.

"It's just like Super Glue," said Don Davis, professor of plant pathology at Pennsylvania State University's College of Agricultural Sciences. Davis and Larry Kuhns, professor of horticulture, have been leading a five-year study of the fungus, and they expect the study to continue for several more years.

Davis said he gets 20 to 30 calls a week during the fungus' most active seasons - generally spring and fall when temperatures range between 50 and 68 degrees.  Davis said the rapid spread of the fungus and the growing number of fungi-damaged homes appear to be linked to the growing use of mulches made from recycled hardwood scraps and tree stumps.

Homeowners can take a key step to control artillery fungus by cleaning up wood mulch around the house and disposing of it before the shooting starts again in April or May.

Here are some additional tips:

  • Control: Bark mulch appears to be more resistant to the fungus than wood-chip mulch. Davis said pine-bark chunks seem to be the most resistant, and cedar, redwood and cypress mulch also appear to be resistant. "Even these mulches should be replaced every few years," he said.

  • Davis said stone mulch (usually small, decorative stones) "is the ultimate answer" to artillery fungus. Black plastic, held in place by stones or boards, is also safe, and some homeowners are getting good results with leaf mulch.

  • Kuhns said fungicides do not work well because "it's hard to determine when the mulch becomes infested, making the timing of the application difficult."

  • Insurance: If your house is damaged by artillery fungus, check with the agent handling your homeowners insurance. Most policies do not cover damage from fungus or mildew, but some do.

  • Power-washing: Once the fungus becomes attached to a surface, even power-washing is not effective.

  • One power-washing expert said he was able to remove the fungus using 200-degree water, with water pressure of 3,000 pounds per square inch, but this combination of hot water and high pressure is certain to damage most types of siding.

  • Scraping: Artillery fungus can be removed from windows by scraping with a razor blade. Scraping also can remove some of the black specks from smooth siding, but several homeowners who tried this reported that a brown residue remains and can't be removed. Scraping can gouge vinyl and painted siding.(REPRINT OF ARTICLE)

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