Pythium Blight

What it looks like

Small sunken circular patches up to about a foot wide, with matted, greasy-looking orange or dark gray grass. In wet, humid conditions you may see gray fuzzy growth on the blades. On warm-season grass it starts as small black or purple spots that spread out irregularly.

When it shows up in the Triangle

Shows up in the heart of summer, June through August, usually after a spell of hot days and warm, humid nights — classic setup is a late-day thunderstorm followed by a sticky night.

Where you’ll see it

Can hit any home lawn, but it's worst on turf that stays wet too long or drains poorly.

What you can do

• Water in the early morning so grass isn't wet overnight
• Go light on fertilizer during hot, humid stretches
• Fix drainage issues — downspouts, low spots, shady wet areas
• Avoid mowing over infected patches to keep from spreading it
• Improve airflow around dense or shaded areas if possible