Did you know that the average rainfall for September in Johnson County is almost 5 inches?  Guess how much we've gotten so far this month?  1.02 inches!!!!  Don't let the cooler temperatures fool you, plants can die from drought stress in cool weather too.  New seed also needs the extra water that mother nature isn't providing, at least twice per day for a period of 2-3 weeks.  In addition, do not cease watering once the seed germinates, you'll need to keep giving the plant substantial water until it goes dormant.