If the lawn has enter dormancy from the heat, it is a good idea to water for a couple of hours a day to bring the lawn back from its slumber. The recent storms we are having will also help to accomplish this. If there are just a couple of bare areas, this can be redone with spot seeding or over seeding the entire yard. Over seeding is the process of laying new seed into the turf to improve its density and fill in the gaps. Aerating along with over seeding will help the lawn to looks its best in the spring. This will give the new seed a place to thrive.
If you yard has a barren look to it, this may be a sign that it`s time to start over from fresh. September is a great time to spray the yard to completely kill it off and be ready for fall renovation. Completely reseeding or sodding will give you the extra step to a fresh green lawn. We highly suggest a soil test to see how the ground looks before new seed is applied. The university of Missouri extension offices offer this service along with many nurseries in the area.