You should be fine. In nature, the grass seed has to make it down through all the dead vegetable mass from the year before. It has no problems doing so. That's why they're spiky things, so they can shift and tumble through very small holes.

Some will sprout IN the mass. That's also fine, it holds air and water, and forms a good initial sprouting humus. The roots will continue to grow down and the crown will shift downwards as the leaves rot off.

Sorry, I was in a rush earlier.

The leaves, if anything, are strengthening the lawn. They don't choke it out (they're quite light), but they do mulch it to moderate temperatures and moisture levels. As they decay, they feed the resources the tree took from the four to eight inch level and drop them up top, where they slowly work down again. Except some of that carbon will hang around for centuries...

thanks for the reassurance. the mulched leaves on top of the fungus thinned grass looks comically bad. my wife has given me an earful about how nobody else mowed their leaves and how terrible it looks. but no lawns around here look good right now, none are green. hopefully next year at this time I will get this grass thick again and greenest on the block

Mulched leaves will eventually glue flat to the surface of the soil and stay frozen there for the rest of the winter. For that reason I would seed now and let the seed make the soil contact first.

There is no reason to not seed now but getting the seed under the leaf cover will be more difficult as time goes by.
In nature June grasses drop there seed in June.

is there a downside to putting seed down more than once? besides wasting seed? thinking i could put some on now and then later closer to spring.

No absolutely no problem - on top of that seed is relatively cheap considering all other home repair type costs.

Different parts of the year have its pros/cons for seeding. By doing a split app - the risks are at least divided.

If you put to much down...and somehow it all does really well....you can have an overly thick seedling issue - but not sure i have ever seen/heard this discussed with dormant seeding.

I agree that seeding both times is a good idea and I would apply in fractions for each seeding rather than waste seed on full amounts according to package instructions.

Chris, how did the mulched leaves and the dormant seeding go? I plan on dormant seeding myself but I have fair amount leaves as well. I normally just mow leaves into the lawn but if it effects the seed germination next spring then I will remove the leaves. thanks

Actually, any type of organic matter to cover the seed is a good thing, as long as it doesn't suffocate the germination. Mulched leaves should be mulched well and the grass left long. Sometimes a double-mow is necessary in certain areas.

Do you apply any herbicides this time of year? Those effect germination even as weed'n feed products.

Here is a couple of pics to compare, taken about a year apart

Wow Chris, that is an amazing improvement. I am using native plants(grasses and sedges) to overseed and they are not cheap. I guess I will continue collect the leaves until I dormant seed, most likely in December (I am in Michigan 5b). I will then mulch the leaves over the seed. Its a lot of work with my push mower but hopefully worth it.

Maplerbirch, I don't apply herbicide at all (which is why probably have such a diverse lawn).

I didn't pick up the leaves, I just mowed them and over seeded on top. If you pick them up and then seed then I don't see any question at all about putting the mulched leaves on top.

Excellent. Many thanks for the help.