If it's moist, you don't have to water. My seed bed wasn't getting water for six days last week during the drizzly/cloudy period we had. Even Friday it would have held, but I wasn't playing with 95 degree temperatures!

If you're uncomfortable, water it--but don't allow water to puddle or, worse, run off! And too wet is asking for seed to rot, so there is a happy medium. If you kneel in pants and come up five seconds later with a wet knee, don't water. Damp, you should be thinking about it. Just the smallest dampish spot and that means water.

I like that kneel in pants thing, thanks. I didn't get a chance to throw down some straw. It will be ok to walk on it tomorrow evening to get straw down, correct? I won't do any damage to anything by walking on it 20 hours after seeding?

I won't do any damage to anything by walking on it 20 hours after seeding?

With the weather we're having in the Lehigh Valley today, you'll be just fine. If you're squishing around out there, step lightly. Very lightly. If possible, fly over those particular wet areas. :-)

Twenty hours in, the seed's still in pre-germination. Absolutely nothing has sprouted, or is really thinking about it yet (that starts around day 7 at the earliest). Through most of the lawn you'll just be increasing your seed/soil contact.

For the first five or so days, don't be afraid to walk it if you need to. I wouldn't traipse around inspecting things, but if an area needs something, do it.

After that, stay off it until October first, if possible. Ignore weeds.

About the keeping off the grass until October... The Purdue University turf web-site says that when overseeding, not total renovation but just overseeding, to keep the existing grass cut to 1.5 inches to prevent compitition from the established grass until the new seedlings have been cut at least two times. Kind of hard to stay off the grass and cut it at the same time.

Here is a link that might be useful: purdue turfgrass

Mark,

You make an excellent point and it is another reason I am glad I've done total renovations over the last two years to various parts of my yard.

It's just easier to make the transition by killing off the old lawn so there isn't any competition for the new elite KBGs.

Also, it's pretty nice not having to cut a big section of your yard for two months or so (Which is how long it took the new lawn to grow tall enough to warrant cutting last year).

Kind of hard to stay off the grass and cut it at the same time.

True, very true. Fortunately, with an overseeding, the old grass is cushioning the new stuff, plus providing enough root structure to hold it in place.

It's just easier to make the transition by killing off the old lawn so there isn't any competition for the new elite KBGs.

Agreed. I can stand at the driveway edge and look out to the new grass. And weeds, but that's another story.

I thought that one of the reasons for scalping the existing lawn was so that you wouldn't need to mow for a while. My understanding is that mowers create suction and can keep disturbing ungerminated seed and possibly even pull out new seedlings. I would think that mowing short would increase the suction effect of the mower blade.