Where do you live? I'm sensing the Chicago area.

What kind of grass do you have (assuming fescue, Kentucky bluegrass, and/or rye)?

Now is the time to fix it. Early spring (January to March) can work, but any later and you're back to having a crabgrass lawn again. NOW is the time.

Most problems in lawns come from watering wrong? If you were not watering at all, that's often much better than watering too frequently. Did you water at all?

Chicago Area

KBG

Definitely wasn't watering enough. I can tell because the areas that are partially shaded or low areas where water would collect are still very healthy and weed free. My plan for the rest of the growing season is to water heavily once a week and hit it with Milorganite every 3 weeks. Thoughts?

Should I address the weeds at this time or let the KBG do the work?

Thanks