Identifying Black Spots on Grass: Sooty Mold vs. Puffball Spores

Two Possibilities

1. Sooty Mold (Aphid-Related)

• Black, oily, wipes off easily.
• Caused by aphid honeydew on blades.
• Treat aphids (insecticidal soap, neem, beneficial insects) → mold disappears.
• Uncommon on turf; check nearby plants.

2. Puffball / Earthstar Spores

• Mushroom-like structure; when mashed, releases black powder (spores) with oily sheen.
• Spores are microscopic, clump like oil.
• Harmless to grass; will vanish in late summer.
• No treatment needed.

If Uncertain

Contact local ag agent for tissue/pest/soil analysis. But most likely: puffballs. They’re a sign of healthy soil fungi.