I live in Central Kentucky. In late September, I killed off my 14,000
square foot back lawn with Roundup (65% weeds courtesy of my
homebuilder).

On October 2, I reseeded with a turf type tall fescue blend (Crossfire
II, Avenger and Cochise III) using a slit seeder. I applied the seed
at 10 lb.+/1K sq. ft. in a criss-cross pattern and I applied Scott's
Starter fertilizer at the recommended rate at the same time. I have
watered and continue to water with an automatic underground irrigation
system 3 times per day (about 8 minutes each watering). I first saw
evidence of germination on October 8. There has been 1 1/2 days of
rain so far and the temperature has been varied -- high 50's to mid
70's daytime and mid 40's to low 60's nights.

Now, germination appears to have started to take off to some extent as
there are seedlings up to 1" tall growing fairly uniformly over most of
the yard, but I have 3 or 4 fairly large areas and several smaller
patches that show no evidence of germination. One area is a rather
large (about 10' X 70')strip in the very back of my lawn. I can discern
no real difference in the amount of water, soil conditions, etc.
between the areas showing germination and those where there is no
germination -- the "bare" areas are directly adjacent to those showing
germination.

My questions are these:

What could have caused this patchy germination?

Should I reseed the bare areas now?

Should I give the bare areas more time to germinate? If so, how long?
Should I then reseed after waiting?

Any help is much appreciated!