On 23 Sep 2006 09:29:05 -0700, "bthiede"
wrote:

I recently killed, tilled, then reseeded my lawn (3 weeks ago). The
grass came in OK, but there are still lots of bare areas. What can I
do about this? Can you overseed new seedlings, or will that risk
overcrowding them and killing what I already have? Could I just
selectively overseed the bare areas? Or should I just wait until
spring to overseed?

Fill the in bare spots with more seed, preferably the same
brand/blend. I don't know your specific location, but it is probably
better to seed now than in spring because the ground is warmer and the
grass will have all winter to grow roots. Next spring you will have
to deal with weeds.