How do you remove mold from cement and dirt areas in a backyard
Placer County California
Since mold spores and their food sources are everywhere, the only real control we have is moisture management. The Master Gardener guide has some tips for snow mold.
In it, it talks about soil alkalinity and, poor drainage, and poor air movement being key factors to growing mold, algae, moss, and lichens on the ground, grass and landscape components. For the stones and cement, scrape off what you can and then wash with a good cleaner, like those recommended for cleaning the home exterior. A good push broom may help provide the scrubbing action needed.
A more permanent solution would include actions that open up the landscape to allow more air movement. Like trimming trees and bushes or removing some to let more sunlight in.