Good News

• As unattractive as many types of molds or fungus may be in your mulch they are not harmful. Some may even be beneficial to healthy soil. Wood mulch is a welcoming home to mold. It is moist and dark just where a fungus wants to live and thrive. To avoid molds, you can consider other types of mulch such as gravel or rock, rubber or pine straw.
  
  

Mold Types

• Artillery fungus is typically very small with an orange, brown or cream colored cup with a black "egg" at the top. This type shoots spores up to 20 feet or more in the air, so it can become troublesome and spread. There is no way to get rid of this type except by removing the affected mulch, bagging it up and throwing it out. Once you do that you may want to cover the area that is now exposed with plastic. Another kind of mold frequently encountered in mulch is slime mold. It looks exactly like it sounds: slimy. One of the more common molds is Fuligo septic, known commonly as "dog vomit" slime mold. The good news is that it will eventually dry up, turn into powder and go away. Again there is no known product or way to eliminate this mold except by removing it with a shovel and discarding. You can also use a rake to break it apart and turn your mulch. Your typical lawn mushrooms may sprout up as well again. Just remove them manually or spray them with a garden hose to dislodge them.
  
  

Prevention

• Winning the war on mold isn't easy so trying to prevent it is the best option. You can change the type of mulch, but if you really want to use wood there are a few things you can do to prevent mold growth. Increase nitrogen by adding grass clippings before you lay your mulch, about a handful or two per bag of mulch. Also pay attention to the depth of your mulch. You only need a couple of inches, and the deeper your mulch the more likely fungus and mold will grow. Avoid the small chip or shredded wood mulches and go with a larger, coarse bark.
  
  

Cautions

• The kinds of mold in your mulch are typically not harmful to humans or to your health, unless ingested. If you are concerned about the spores and would rather be safe than sorry, wear gloves and a face mask during removal.