Yellow Slime Mold in Mulch: Organic Treatment

Identifying the Fungus

A yellow slimy substance in mulched flower beds dries to brown/tan clumps. It appears in sun and shade. The respondent identifies it as a fungus (likely slime mold) and recommends horticultural corn meal at 10–15 lbs per 1,000 sq ft, watered in. Raking out dried clumps helps.

Source and Prevention

Many such fungi originate from dead, rotting roots underground. Digging out the source is ideal. The respondent notes that agricultural extension agencies favor chemicals and may not endorse organics, but corn meal is highly effective—even for toenail fungus (soak feet in corn meal tea). Periodic raking to aerate mulch and keep it dry also helps.