may not be the word, after all, as Joe Ponessa, emeritus
professor of housing, indoor environment and health at
Rutgers Cooperative Extension, sees it.
was responding to a recent column in which a reader
reported what looked like "light grease stains on a
portion of vinyl siding in the rear of the house."
professor says: "If the ‘grease stains’ on
siding are not slippery but in the form of small, hard
black dots, they are most likely spores from artillery
fungus, which grows in organic matter, forms vase-shaped
structures that are capable of firing out spores six
feet or more, and that are especially attracted to
light-colored surfaces. They are notoriously difficult
to remove, says Ponessa, who adds that he once tried a
series of powerful organic solvents and that none
may be the source of the problem, he says, and it has
been suggested that bark mulch may be less problematic
than wood mulch. The best prevention is to use gravel or
black plastic as a mulch near buildings (or where cars
Internet search brings up informative fact sheets from
the Cornell and Penn State Cooperative Extensions, he
latter lists numerous reader suggestions that might be
helpful, and information from a professor there who has
studied this issue.
wrote about artillery mulch a few years back, and it was
then that I decided to use mulch only when it doesn’t
come into contact with my house.
Cornell University’s Plant Disease Diagnostic Clinic
come these details:
fungi spores do not normally structurally damage the
houses, cars, and plants they cover."
the fungi is virtually impossible. Scrubbing and
scraping with tools or washing with soap and water aids
somewhat in removal; however, the use of tools or harsh
chemicals may damage painted or otherwise colored
fungicide treatment is recommended at this time."