Identifying Strange Lawn Growth: Fungus, Worm Castings, or Dog Waste?

A Los Angeles homeowner finds ¼–½ inch brownish-pink bulb-like growths in the lawn, soft like mushrooms, smelling fungal when broken. Photos show clusters along a sidewalk.

Possible Causes

• Decomposing dog feces – Anaerobic breakdown creates smelly, fused balls along walkways. Most likely given location.
• Worm castings – Usually smaller, odorless, granular.
• Anaerobic organic matter – Wet grass clippings in clumps can ferment, but woody texture is odd.
• True fungus/mushroom – Unlikely at this size/shape without visible caps.

Action Plan

1. Remove growths manually; wear gloves, wash hands.
2. Monitor for recurrence.
3. If persists 2–3 months, submit sample to county extension office.

Risk Level

Not likely dangerous to humans or dogs, but unpleasant. Probably not a pathogenic lawn disease.

Keep cleaning up; if it's dog waste, the problem solves itself with source removal.