I have a lawn which I inherited 15 years ago, on purchasing my home. It
appears to be a mixture of several kinds of lawn grasses, plus clover,
crab grass, and weeds(which I continually pull out). My thought was to
spread grass seed over it and try to get it to look more uniform. My
grass also shows no tolerance to dry spells, although I have been giving
it plenty of 10-10-10 fertilizer. What preparations
should I do for overseeding, and what is the best time to do it? Can I
simply drop the seeds onto the lawn, or should I first add some top soil
for the seeds to take hold? What kind of grass seed will be drought
resistant here in the Midwest?

Sherwin D.