On Fri, 02 Sep 2011 09:49:33 -0400, Rebel1
wrote:

Those are my two choices before overseeding my 12,000 sq ft lawn in
central NJ. Few companies offer dethatching, but I'm not sure if that's
for their convenience or because aerating is really the best way to go.
I would describe the lawn as good; not the best or the worst in the
neighborhood. Soil is loam. Problems are bare spots, clover, crabgrass
and a few misc weeks. I keep after the dandelions, so they are under
control.

Regarding aerating: The seeds that fall into the holes are about 1.5
inches below the soil surface, far below the fraction of an inch seed
companies recommend. While these seeds won't have any soil covering
them, will they still germinate properly? And if they do, when fully
established will the grass from the seeds in the holes look different
from the surrounding grass?

TIA for your responses.

R1
2 totally different procedures - with 2 totally different purposes.
Personally I'd do both. Core aerate first - then dethatch. The core
holes will fill with loose material and the seeds will be able to
contact actual soil instead of thatch.