The summer of 2011 was a very wet summer in Minneapolis, MN. The rain and damp soil helped the grass and the flowers stay beautiful all summer. The wet summer allowed many other things around your yard to flourish such as weeds, mold, and crab grass.
Mold can also be encouraged by wet and humid conditions. Slime molds for instance survive winters as spores in the soil or deep in thatch layers or mulch. When cool and wet they germinate and form mobile spores that feed on organic matter and microorganisms. At some point these spores may then gather together and move up out of the soil onto grass blades, mulch, plant stems, and even trees and shrubs. At this point they appear as blobby jelly-like masses.
Parkway Lawn can help you with infestations such as these.
Learn more about crab grass control: