On Tue, 5 Dec 2006 21:02:12 -0500, Buck Turgidson wrote:
A few years ago (before the Internet), I heard that overseeding a lawn here
in the DC area in January was a good thing to do. The idea was that the
seed would work itself into the soil during the daily freeze/thaw cycles,
and by spring it would germinate and thicken the lawn.

Depends on the species of grasses involved (you probably don't want to do this
with warm season grasses, the ones that stay green in summer), but it's ok
for cool season species -- they germinate after cold treatment, preferably in
a warm/cool cycle (that's actually how they test the seed for germination) --
several weeks in a cool refrigerator on a germination medium, then onto a
lighted germination chamber for diurnal cycling.

January strikes me a bit early for overseeding in the DC area... you may lose
significant amounts to birds and erosion before the soil temps are up to
germination temperatures.

Best bet is to call one of the local cooperative extension service agencies in
the DC area and ask when they suggest overseeding. I usually overseed in
February in the Portland, OR, area.

Kay