On Sun, 9 Sep 2012 13:54:22 -0700 (PDT), "
wrote:

As a result of the midwest drought (that may be almost over), my yard
has many areas where the grass is dead and the surface is a brown/tan
dead thatch. In those areas less than a foot in diameter I expect the
rhizomes from the surrounding grass will fill in by next Spring, and I
plan on leaving the thatch alone so as to not disturb the new
rhizomes. But, I don't know whether larger thatch areas will fill in
or not, and whether or not I should remove the thatch if do not reseed
those areas.

Anyone have first-hand experience?

Turf grasses go dormant during droughts same as they do in New England
in winter. It's still plenty early enough in the midwest to irrigate
before a hard freeze sets in. Water your entire lawn generously every
afternoon and in two weeks it'll be all green and growing. Don't mow
too short, especially just prior to winter... don't mow shorter than
three inches prior to winter or during dry spells. If you're lucky
you'll get some good rain this time of year. Midwest is a vrey broad
definition encompassing many biomes, and there are many types of
grasses, but in general every turf grass needs adequate irrigation to
green up. I mow over ten acres of turf and we had a drought here in
New England this summer, most of my lawn went brown and it's too large
an area to water, I only watered specific plants. But then the rains
came and everything is green and growing... in fact I'm hoping the
rains stop long enough so things can dry so I can mow one last time
before winter.