Why Mulch

• Garden mulch keeps down weeds, conserves moisture, discourages pests, controls erosion and moderates soil temperature, according to Iowa State University Extension.
  
  

Organic vs. Inorganic

• Organic mulches, such as shredded leaves, pine needles, grass clippings and straw, eventually decompose, adding vital soil nutrients and increasing drainage. Inorganic mulches, such as black plastic and aluminum foil, last a long time and can be reused season after season.
  
  

Mulch Mold

• Mulch material, temperature, pH and moisture determine whether your mulch mold is naughty or nice, according to Ohio State University. Shotgun or artillery fungus produces tiny spores that form black spots on plants and causes damage.
  
  

Slime Mold

• Slime Mold (no longer classified as a fungus, but gardeners often mistake it for one) spreads in yellow or orange patches throughout a garden and can cover or shade plants.
  
  

Cures

• Ohio State University advises gardeners to dig nuisance mold into surface soil and soak with water, or to heap mulch into a pile and soak with water. This will cause the mulch to heat and destroy the fungi.