It is still too hot to be reseeding your lawn says University of Illinois Extension Horticulture Educator Chris Enroth:
“Between August 15th and September 15th, that is a great time of the year for us to do some lawn care. Just wait a little bit longer and we can go out there and start reseeding and doing a little bit of rehab and revitalization of some of our lawns.”
To best care for your lawn, Enroth advises mowing high, mowing often, and keeping the mower blades sharp.