we have a fairly large corner lot, the lawn grass on half of this lot is fine, the other half suddenly sprouted what looks like black mold on numerous small patches of the lawn on the other half of our yard. we have not done anything unique to this one affected side. we have watered, fertilized and put out a broadleaf weed killer to the entire lawn but only half of it has this mold looking substance on it?
Submitted by BHGPhotoContest

This sounds like slime mold. It's not uncommon on lawns, particularly in wet conditions. It does not actually harm the lawn, and will disappear if conditions dry out. Slime is kind of neat -- it actually moves around at night and in early, damp  mornings. Then when it gets hot, it stops and just looks like this dark patch on your lawn.

You didn't specify if the lawn is dying out underneath these patches. If it is, then it's NOT slime mold and you should take a sample into a garden center or extension office for an ID.

Answered by BHGgardenEditors