First the Cold, Now the Mold!

As winter (finally!) comes to an end, many homeowners are dealing with another kind of “white stuff” on their lawn:  mold.  There are two types of snow mold:  Grey Snow Mold (Typhula blight) and Pink Snow Mold (Fusarium patch), both of which are fungal diseases that are common in spring lawns.

Snow mold develops when there is an extended period of snow cover on ground that is not completely frozen. It can also be brought on if a lawn is not properly prepared for winter.  For example, a badly timed fertilizer application can cause a flush of growth too late in the fall.  Snow mold can also thrive under leaves that have not been cleaned up or in long grass that should have been mowed one last time before winter set in.

Seeing Spots?

Snow mold damage looks like circular patches of dead, matted grass. It is not unusual to find both gray and pink snow mold together.  While both are more or less white, grey-hued snow mold only infects the leafs of grass while pink snow mold does more damage because it attacks the entire crown of the plant.

Pink snow mold is distinguished by the pink color of the web-like mycelium growing on the grass surface. When the grass is wet, the moldy growth looks like white cobwebs, but it turns pink as it matures then disappears when the grass dries.  Gray snow mold is similar, except its mycelium stays whitish-gray and it produces tiny black mycelial masses (sclerotia) on the grass blades.

Spring Cleaning!

Fungicides are available to both prevent and treat snow mold, but because the damage is largely superficial and temporary, you’re probably better off handling it with a little spring cleaning in your yard.  Simply raking the infected area will remove thatch and debris and speed up the drying process – once the grass is dry, the mold will dry up too and your lawn will then grow out and renew itself.  Some overseeding may be necessary or, if there is a great deal of damage, topdressing can be applied and areas can be repaired like a bare patch.

Although it can look really nasty, most snow mold damage will recover with little or no work on your part.  If that’s not enough of a silver lining, just remember that it’s also a sure sign of spring and warmer days are certainly on the way!