Mysterious Colored Powder on Garden Soil: Slime Molds Are Harmless

A gardener found turquoise and orange powdery/mossy substances on the vegetable bed soil. Previous owner used pesticides; they've been there 10+ years. Husband turned it under.

Diagnosis

Almost certainly slime molds (myxomycetes)—common on decomposing organic matter, especially new mulch. Harmless to plants.

Husband Did the Right Thing

Turning them under incorporates the organic matter and disrupts the fruiting bodies. No further action needed.