Do not be too alarmed over the yellow plant fungus sprawled out on your lawn. Yellow fungus is a type of mold that feeds on decaying organic material, so your plants are actually not in harm's way. However, yellow plant fungus is unattractive, so become familiar with control methods to keep this eyesore out of your home garden.
Slime molds are actually not true fungi, though they are "fungus-like" in appearance and often referred to as such. The same slime mold that appears as a bright yellow hue may also display a brown, salmon, cream, red or orange color, according to the Clemson University Extension. One species, Fuligo septica, is known as dog vomit slime mold due to its appearance that begins as a light yellow color, according to the University of Arkansas Cooperative Extension Service.
Though home owners are often alarmed at the sight of this yellow plant fungus found on plants like grass, there is little need for concern. Slime molds are not parasitic in nature and do not directly disturb the plants they cover through a feeding process, according to the Clemson University Extension. Though damage can occur, slime molds are not invasive spreaders.
Like true fungi, slime molds spread sporadically on wind and pop up in wet conditions, particularly during a warm spring season, according to the Clemson University Extension. Slime molds are often found in shaded areas that remain moist --like lawn surfaces or at the base of a tree or shrub--where ideal culture promotes the proliferation of spores into a large colony, according to the Cornell University Plant Disease Diagnostic Clinic.
Yellow plant fungus slime molds cover grasses and mulches because they feed on bacteria and fungi and dead organic matter as it decays. Though slime molds do not feed on green plants, they can harm the plants they cover by blocking sunlight and oxygen flow. Fortunately, however, no major damage will occur past the particular spot the slime mold encompasses, according to the University of Arkansas Cooperative Extension Service.
Since the yellow plant fungus slime molds do not threaten your landscape, control is not imperative. However, if the sight of these molds is problematic, you have a few options. If dry weather is fast approaching, leave the slime mold as it will dry up when in the absence of moisture. For immediate removal in dry conditions, remove the mold with water from a garden hose, according to the Clemson University Extension. However, if you live in a humid climate, do not use water as a means of removal as it will spread the problem. Use a rake in any climate to manually rid your landscape of the mold.