You don't need to, but you will have better results if you do. Contrary to what people say, birds won't flock to your yard and eat all the seed, but besides that the topdress has a few important functions. It prevents the seeds from drying out as fast as they would without a topdress. It can prevent some erosion and seed washout in the event of a quick thunderstorm. It provides more seed to soil contact if they are covered with peatmoss. Shredded straw is good too, it's cheaper and easier to apply, and one bale goes a long way. The straw prevents puddling to an extent, and also keeps the seedbed moist.

Top dressing with soil first is a huge mistake in my opinion. Unless you have poorly graded property now, leave the grading alone. And if you have poorly graded property now, please leave the regrading to professionals with real tractors. They also have an "eye" for knowing how much soil is to be added or removed. Adding an inch of soil is 100% guaranteed to screw up an otherwise good situation. At worst you could flood your home. At best you will create a new profile that may make it harder to mow. Taking pictures of screwed up turf surfaces has become a hobby of mine (in addition to writing about lawn care). The worst pic I have shows a hellstrip surface that is 8 full inches above the surrounding concrete sidewalk and curb. Please don't get started down that path.

I think you do not need to cover the seed as long as you have rolled it. And roll heavy. The roller is the right weight when you cannot see your foot prints in the soil behind the roller.

Well I certainly disagree with San Antonia, putting a thin layer of compost over ANY lawn, at any time, can only help the soil conserve moisture.
If the 1/2" layer of soil that is added is of organic nature, i.e. compost, it adds organic material and thereby increases the soil's ability to conserve.

Such thin layer to aid the seed to make better contact can hardly cause increased chances of raising the level or causing untold harm in any fashion.

The overseeding done now ..in the fall, is the correct and wisest time to accomplish the start of a good lawn.
Repeating the layer of compost, and overseeding--especially in hard to grow or bare spots, in the spring and in the fall...routinely given every year, will increase the chance the lawn will not give problems down the road.

If you reread what David posted, he never said that compost would raise the level. He was addressing what happens when soil is added.

I pretty much always topdress with a thin layer of Black Kow compost. I have a small yard, so it's relatively easy for me to apply by hand.

Can I cover a smallish area with light remay (floating row cover) since I have lots of it? I will, of course, water 2-3 times a day. I put a fine layer of screened compost on it before seeding. The area is dreadfully weed=filled and I mowed it low and raked it vigorously.

this is a test area and I will then do more if I seem to be having success - I got seed recommended from my local Agway and in another spot where there was new soil it did very well - combination sun/shade - so now I want to use same seed for overseeding.

thanks for advice

My first post. :) This website is great. I have learned a lot by reading these posts. Especially dchall and tiemco.

Anyway, I'm in Columbus and recently started my lawn reno. Its been 2 weeks and I have pretty good growth (in my amateur opinion). I dropped tttf seed and covered it with compost. Near the end of my lawn I ran out of compost and the seed was simply dropped onto dead grass mowed to 1.5". The germination appears exactly the same between naked seed and the seed covered with compost top dressing.

This may be anecdotal evidence but it has been my experience. That being said, I would still topdress with compost for piece of mind.

Has no one heard of top dressing with Turface? used in ball field restoration. it's the consistency of kitty litter, small clay particles that hold moisture against the seed when wetted.

Turface sounds interesting. Where do you get it?

I put bedsheets over mine and it done well