Need A New Worry?—

 Artillery Fungus May Have You In Its Sights

By Nancy K. Crevier

Tammi Jacob spent ten grueling hours scraping tiny black spots off of her glass-topped patio tables with a single-edge razor blade before storing them for the winter. Bob and Brendan LaMarche labored an entire day to remove small, sticky dark brown specks that covered Brendan’s white car, first scraping with a hard rubber spatula, then using bug and tar remover to get rid of the nasty brown stains left behind.

Neither Mrs Jacob nor the LaMarches had any idea at the time that they were dealing with a frustrating problem they had inadvertently brought on themselves. All they knew was that an infestation of tiny, globular particles with the adhesive power of super glue had led to a lot of back-breaking, shoulder-aching scraping and scrubbing — and still left them with less than perfect results.

“It looked like insect waste material,” says Marty LaMarche. “Like the gypsy moth caterpillar droppings you used to see.”

Donna O’Connor had been told that the poppy seed-sized spots stuck all over her Valley View house were spider droppings, a diagnosis given by her sister’s handyman.

“I was scared to death that the house was totally invaded by billions of spiders,” she says, speculating how many arachnids it would take to deface the exterior of her home.

But insect dung it was not.

What the LaMarche family, Tammi and Randy Jacob, Donna O’Connor, and other Newtown residents eventually discovered was that the mulch they had spent hours spreading on gardens and around their house foundations was infected with “artillery fungus.”

Artillery fungus, or Sphaerobolus stellatus, is a fungus associated with wood mulches, and the annoying problem it causes has increased as quickly as the popularity of wood mulch landscaping has all over New England.

When temperatures hover between 50 and 68 degrees Fahrenheit, and cool, damp conditions (such as the region has encountered the past two springs and falls) are in place, artillery fungus multiplies in the substrata of decaying plant materials, barks, or animal manure. The tiny, round fruiting body splits open when mature to form a cup containing spores, or peridioles. When the light sensitive peridioles are exposed to a bright source such as the sun or reflective surfaces, the mass of sticky spores is expelled violently from the fungus. If a pale-colored wall or car is within 20 feet, it will be the target of the 1–2 mm globs that defy removal.

The initial reaction from home and car owners is to try to manually remove the spots. Fingernails, razor blades, spatulas, and putty knives are put to work. At best, hours of work will remove only hundreds of the millions of minute, sticky dots. Bristle brushes and scrub pads join the work force, with only slightly improved outcomes. At best, careful scraping gets rid of the raised dot, but leaves behind a circular stain. Too vigorous scrubbing can destroy the paint surface of a building or automobile.

All of the rubbing and scrubbing may be pointless, too, if a tarp or other material is not in place to catch the spores as they are removed. The spores can survive for up to 12 years, and will reinfest the ground they fall upon.

Next, washing off the offensive spots is tried. Hot water, steam cleaning, bleach and other household cleaners are put to the test — with mediocre results.

There has been limited success with power washing vinyl sided houses to remove the spores, but power washing takes off paint and car finishes, as well; unless you are planning to repaint your house or car, it is not always a viable solution.

Unfortunately, landscapers and mulch suppliers cannot offer better solutions. A fungicide has not yet been recommended for artillery fungus. If the peridioles can be removed before they have a chance to dry on the surface, there is a better chance of getting rid of them. This is rarely the case, however, as it is frequently weeks, months or years before people identify the problem.

New Mulch/Old Mulch

Jim Walsh, of Walsh Wood Services on Route 34 in Sandy Hook. has been in the mulch business for more than 25 years. It is within the last ten years that he has heard complaints about artillery fungus, although the nuisance has been in the Northeast region for many more years than that, he says. He blames the recent increase of artillery fungus on companies that use substandard products in their mulches. Recycled mulch is fine, but not if it includes stump, root, pallet, or furniture by-products.

All of Walsh Wood Services products are of virgin wood, and the thousands of yards of mulch sit less than one season. Mr Walsh says these two factors prevent fungus problems in his product. Problems crop up when people dump new mulch on top of old mulch, in his opinion, or on top of poor quality mulch.

“Old mulch,” says this mulch expert, “needs to be removed or at least loosened every year. Turn it over.” Think of the mulch bed as you would think of a garden bed, he suggests.

“You wouldn’t just throw seed on the ground in the spring and expect them to grow.”

By using a toothed hoe to turn over mulch in the spring, the packed layers of mulch are broken down, giving the product an opportunity to dry out. Oxygen is introduced into the layers, which slows down production of artillery fungus.

The best thing, Mr Walsh recommends, is to get rid of last year’s mulch. It doesn’t have to go to waste. By placing the old mulch around the perimeter of the yard, homeowner’s can create a tick barrier, and any artillery fungus the mulch may harbor is growing in a harmless place.

Patti and Craig Nichols’ problems with artillery fungus began two years ago, when they decided that the previous year’s mulch was still looking good enough to save them the trouble of replacing it in the spring. Then they noticed black specks stuck tenaciously to the house, doors, and screens.

“I thought at first it must be some sort of mold,” Mrs Nichols says, “but when I noticed it all the way up to the second story screen, I knew it had to be something else.” She made use of her computer literacy, researching single-mindedly until she uncovered articles that identified her problem. It was artillery fungus.

To her dismay, she read that mulches on the north sides of homes, where her problem occurred, that were not regularly turned for aeration, needed to be replaced or covered lightly each year with a new layer of bark mulch to prevent infestation. By electing to leave down their colored mulch that spring, the Nicholses had set themselves up for an attack by the fungus.

Ultimately, they chose to power wash their home in Newtown to the tune of $800, after hauling away the yards of mulch they had banked around the foundation.

The Department of Plant Pathology and Ecology at the Connecticut Agricultural Experiment Station affirms Jim Walsh’s advice — removal of the infected mulch is the best way to control this fungus. Old mulch can be overlaid with a thin layer of fresh mulch that contains at least 85 percent bark mulch. Where mulches are in highest contact with housing, cars, or bright surfaces, nonwood mulches can be utilized. These would include gravel, stone, marble chips, or black plastic — which give a very different, and not always desirable, look to landscaping.

The Nicholses looked into using artificial mulch made from recycled rubber, but did not like the idea of placing what seemed a potential fire hazard all around their house. Plus, they like the look of natural mulches.

“It’s a lot of work,” says Mrs Nichols, referring to the toil of digging out the old mulch each spring and replacing it with new. They have switched to cedar mulch, which is less susceptible to the fungus, and put in extra gardening time each summer now, turning the mulch to keep it dry.

Using a natural, living ground cover in place of mulch is another alternative. Tammi and Randy Jacob replaced one section of the 15 yards of mulch they laid down with pachysandra and creeping pine. Until it fills in, they are using just a light layer of shredded cypress mulch to discourage the weeds.

The good news is that artillery fungus causes no known health problems, nor do they cause structural problems to cars, boats, houses, or other material on which they land. The bad news is that once the fungus is settled into your mulch, only hard work and yearly tending to the mulch plots will alleviate the dilemma.

Wash the windows, paint the house, plant the gardens, mow the lawn, trim the bushes — a homeowner’s work never ends. And don’t forget to add one more item to your “to do” list: turn and replace that mulch each year.