Black Honeycomb Fungus in Flower Bed: Slime Mold or Something Worse?

Question: Soil covered with black honeycomb fungus with seed pods in each cell. Comes up in sheets. Killing plants. Sprayed fungicide—enough?

Diagnosis

It's a fungus (slime mold). Most don't hurt plants unless they shade them. But they often indicate excessive moisture, poor aeration from too much mulch—conditions that also favor Phytophthora, Pythium, and other deadly soil fungi.

Treatment

Blast surface fungus apart with water hose to prevent reproductive stage. Use proper fungicide every 2-3 weeks to eliminate problem.