What did you use to kill the weeds? The label will indicate how soon you can seed.

As far as dethatching and aerating, it can be done before seeding. You likely don't need a slit seeder for overseeding, a broadcast spreader works well.

Aerating or dethatching is up to you. If there's a lot of dead material, dethatching may help.

I would begin gradually mowing the areas to seed lower, don't scalp the good grass. Over the next few mowings, reduce the height a bit. Assuming you have cool season grass.

We're few of us a fan of aeration before seeding. Seeds really don't grow well when they're deposited three inches down, so the holes are of no help. Two, you just damaged the soil biology (that the new grass requires to get a firm start in your lawn).

Dethatch if you must; again, unnecessary, but things that became a real mess may require a little help.

That having been said, there's no need to wait between any mechanical (and some chemical) processes. They can be done one right after the other.

As Philcav noted, the limiter is how soon you can seed post your chosen herbicide.

My sod was a local fescue blend called Green Alliance. It's a blend of Cayenne, Mustang 4 and Corona Tall Fescue. I plan to overseed with the same seed. I've been mowing between 3.5" and 4" for the season. I'll probably start lowering the mower by a notch a week. How low would you suggest finally mowing down to?

I spot sprayed the crabgrass with Roundup Plus. It says I can reseed after three days. I'll be well past that by the time I seed. I'm using Tenacity to knock down the nutsedge. I know it would've killed the crabgrass as well, but it takes a little longer than I have to wait and I have some big clumps/sections that I needed to get killed off quickly in order to have good and dead in time for the power rake.

I'm a big fan of the results of power seeding, but I'm sure I'll have some thin areas that I'll go over with my spreader afterwards. I swear by my drop spreader though, I'd never use a broadcast. I like to know what I'm putting down and where. I want it exactly where I put it, not just kind of thrown around all over the place. It takes a little longer but, again, I prefer the precision and the results.

We have heavy clay soil in our area and I've always heard/read that aerating is good for compacted soil lawns. Now, my timing may be off, but I'm fairly certain aerating in general is still a good idea. Maybe though, I'd be better off doing that in the spring. What's your guys opinions on that?

I politely disagree that aerating is a good idea in general or in any specific case. If you were a lawn guy selling the benefits of aerating, and collecting $250 for doing it, then I'd strongly encourage you to aerate, but other than making his boat payment, there's no reason to aerate. In fact if you want us to, we can give you a list of reasons why it's a bad idea. If you have any benefits you can think of, please, we've heard them all. Those are rumors, hearsay, old wive's tales, myths, and urban legends. There's no science to demonstrate that removing plugs of soil has any benefit.

I also politely disagree that you have heavy clay. I don't know where you live, but unless there's a brick factory within a few blocks, you have something else. How can I be so bold as to make that statement? I've been here since 2002 and after doing a jar test, almost nobody has any clay, let alone heavy clay. That doesn't mean you have heavy soil, gummy soil, or whatever. But the reason is not clay. The reason is a salt imbalance. You can fix that completely, but you have to have a great soil test first.

So even if you did have heavy clay soil, aerating is not necessary. When you get a few serious lawn nuts together on several forums for many years, you start to learn a few things. One is that surfactants work MUCH MUCH better than core aerating to soften hard soil. The professionals use very expensive surfactants. We use shampoo. Spray at a rate of 3 ounces per 1,000 square feet and I promise - you will be taking your brother-in-lawn on a tour of your soft soil within a month. The cost is about 30 cents, so what are you waiting for? You'll never even think about using an aerator again.

Here's what will soften your soil. Fungi. The beneficial fungi living in your soil will soften your soil while you sleep, but they must have nearly continual moisture and temperature. The shampoo allows that to happen by letting moisture penetrate deeper into the ground. Just try it. Again, 30 cents and it only requires you to lift a hose for about 30 minutes.

Back to your issues. In the places where you have spot sprayed the weeds, go back and water those spots to see if any new weed seeds will sprout. It might take daily watering. The idea is to sprout the weeds now, before you seed the grass, so the weeds don't come up with the new grass. It's always so disappointing to get a crop of fast growing weeds instead of grass on a project like this. Then at the last minute, spot spray any new weeds. Then seed.

First, I am not one to routinely aerate but don’t hesitate
to use the practice in order to achieve a specific goal, especially that of developing as ideal of a
soil medium as possible.

Granted, homeowners rarely need the level of maintenance and
care a golf course or professional sports stadium requires but the proven,
tested, science definitely exists. It is admirable a core group of lawn enthusiasts
have formed a coalition to offer alternatives to these proven practices and
more power to you but at least be accurate and balanced in the claims that seem
to me to be incomplete, highlight only the cons, or are without merit of
significance.

I would hesitate to recommend to others anything outside of
personal experience or studies from reputable Universities or professional
organizations like the USGA or field turf organizations. My experience comes from working as a greens keeper during college summers and being around the professional turf grass industry for various reasons so I can only comment with personal experience on the Western half of the PNW, Fine
Fescue, Perennial Ryegrass, Creeping and Colonial Bentgrass. I have not worked with KBG , Tall
Fescue or any of the warm season grasses.

For others just researching the options for your lawn,
consider your goal and budget, weigh the pros and cons with an open mind, and
decide what’s best for you.

"I politely disagree that aerating is a good idea in general
or in any specific case. If you were a lawn guy selling the benefits of
aerating, and collecting $250 for doing it, then I'd strongly encourage you to
aerate, but other than making his boat payment, there's no reason to aerate."

It might be kind to be polite to lawn care
professionals as well. There are plenty with degrees, certifications and extensive
experience that take pride in their profession and make recommendations’ based
on actual knowledge of homeowners’ soil, goals and budget. I assume there are individuals
with deceptive practices in most businesses, including lawn care and your industry.

"In fact if you want us to, we can give you a list of reasons
why it's a bad idea. If you have any benefits you can think of, please, we've
heard them all. Those are rumors, hearsay, old wive's tales, myths, and urban
legends. There's no science to demonstrate that removing plugs of soil has any
benefit."

I’ll bite; please share the list of reasons why it is a bad
idea. I would also like to see links to the science that compares long term
results of spraying soap on poor soil vs amending the soil over time to the optimum
make up. There are MANY tests and studies available on aeration. Just put a few
search terms in. Try “Aeration of Turfgrass” to start but there are many more
terms that will lead you to many more studies. Where are the soap peer reviewed
studies? Your claim "Rumors, hearsay, old wive's tales, myths, and urban legends" is simply proven otherwise.

Hold on a second. You were just asked to provide a list of benefits...which you did not. Nor did you provide any science, but now you're asking for that in return without offering any?

That's called a time waster....and I, anyway, won't play that game with you. You haven't even presented an argument yet, just obstinate refusal to any alternate argument that conflicts with the argument you've not defined as yet.

That having been said, as far as the soap goes you can ruminate on why those amazing, trusty turf care professionals use surfactants on golf courses. We'll wait.

The stated offer was to list the reasons not to which I accepted. A statement was made claiming existing knowledge of any perceived benefits and a claim they were not true. I interpreted "Please, we've heard them all" as , end of debate, don't waste your time, but I apologize if I read that wrong. I did proactively offer one search term, and feel free to try others, that links to studies that dispute a claim of no science.

Also, I am not disputing the usefulness of surfactants. I simply reacted to the "never" ideology promoted. I am be open to whichever practice is best suited to the goals and budget of a homeowner whether that is aeration, surfactants, or a combination of the two.

I'd be very interested to read where major golf courses have stopped aeration in lieu of surfactants and not just as a supplement.

You are the dominant posters and I have no illusion of changing your opinions. I mistakenly thought it might be useful for less knowledgeable visitors to consider all options and make an informed decision.

I commend you for your generous time and knowledge you share by the way.

Regards,

Nice attempt at lawyer-ese, but as noted, a huge time suck for us to no avail since we have no idea of what you think these alleged benefits are.

So, a great try, but you'll move the goalposts regularly without a defined schema and homey don't got time to play dat.

Search for 'surfactant golf course' in the journals. Every land grant university in the country has been doing those for decades. The reason golf courses need all the tools is because they absolutely have to have green grass every day of the year. They force feed and force water it. What happens is they develop a hydrophobic fungus growing on the surface of the grass and soil. When that happens they can water all day long and it just sits on top and evaporates. This is what I get from reading the journals I alluded to above. That sitting water promotes the hydrophobic fungus. In an attempt to break through that surface they tried spine aeration. The spines poke through the surface layer of fungus and allow moisture to penetrate. That works to the extent that the spines have a certain spacing. So the water enters the soil separated by the spine to spine distance. Another attempt to solve the hydrophobicity problem was to use a surfactant like Cascade Plus. That product seems to work in every study. The surfactant has the distinct advantage of breaking through the fungus everywhere so spine to spine distance means nothing. The surfactant has a side effect of softening the soil. We use it simply for the side effect.

But if you would rather break your back bouncing around behind a $250, 500 pound, rental core aerator instead of spending 30 cents and getting a little wet, you go ahead. I'm not coming through the screen to grab you by the throat.

I would hesitate to recommend to others anything outside of
personal experience or studies from reputable Universities or professional
organizations like the USGA or field turf organizations.

That's great for you. We're not hamstrung by that self imposed restriction. Although I did believe the shampoo method of soil softening was bunk until I tried it. Now look at me shouting about it. I also advocate mowing most grasses at "the highest setting," rather than the university recommendation of mowing Midnight Kentucky Bluegrass at 2.65498256 inches and Chocolate Kentucky Blue at 2.65829683 inches. The point is not to mow it at 1 inch. It needs to be tall so just friggin' keep it simple for the homeowner who doesn't have a $5,000 lawn mower to adjust it to fractional inches.

I also advocate watering deeply and infrequently. My land grant university in California taught us to water daily. But here in these forums there was a discussion (kind of a rugged discussion) about the benefits of watering daily versus deep and infrequent. I lost that one. The winner was a lawn care professional from Phoenix who convinced me that if he could water his clients' lawns once a week, that I should be able to do the same. Well whaddaya know, I tried it and he was right.

It might be interesting to know that there is no university research to prove that plowing the ground has any benefits to farmers. People have been doing it for 10,000 years with no research. But there are those no-plow converts who swear up and down that they get better results than when they were plowing. Do you need the science when your pappy tells you it's true? Sometimes you do.

Why not core aerate? Because the cores bring old weed seeds to the surface and sunlight giving them a new chance to germinate. Because removing the cores destroys the soil structure adjacent to the holes as that soil must melt away to fill the holes. Similarly the cores on the surface melt coating the surface with un structured soil. Because the soil microbes at 3 inches deep, now exposed directly to the air, will be destroyed simply because they bury themselves to get away from the air. Because if you're removing cores containing rye or fescue plants, those will not regrow to fill in where you removed them. For me the number 1 reason not to core aerate is because Mother Nature does not core aerate. If it was an important thing to do She would have created some creature somewhere that had hooves hardened in just the right shape to penetrate the soil and remove cores.

>>For me the number 1 reason not to core aerate is because Mother Nature does not core aerate.

Earthworms. Not native to the North American continent, by the way, they were brought over from Europe. Although America had its own worms, they were restricted to areas that the Ice Age didn't cover with ice, and were very slowly moving back northward again. The European Earthworm, Lumbricus terrestris, is now dominant in many soils across the country.

However, earthworm tunnels tend to be incredibly deep, quite trim in width and breadth, very irregular, multiply branched, and semi-permanent. Biology has time to adjust and, once adjusted, happily stays that way for pretty long periods. The worm doesn't tear out grass plants, it moves around roots it can't shift and chooses a different path.

Still, northern forests have had and continue to have problems with earthworms due to the fact that they're invaders, deep drillers, and incredibly efficient organic matter consumers. Since many of our grasses are European, that's not an issue for us.

Thank you for the link and while you make some valid points,
there are many I disagree with but knew before I posted what the responses
would be and morpheuspa says, it is a huge time suck and the deck is stacked on
GardenWeb.

I am and have never been adverse to using or recommending
surfactants. I have only read a few of the articles suggested by your search
term suggestion; This was the first I read and there isn’t anything I disagree
with. The others have also been consistent with my previous understanding of
where, why and when.

https://www.golfcourseindustry.com/gci0414-wetting-agents.aspx

I should have known better than to attempt an open
discussion on this forum and don’t wish to hijack the OP’s thread any more than
it has been.

As two of you have claimed, you are aware of all the perceived
advantages; I feel I am well aware of the perceived disadvantages championed by
the anti-Tilling, aeration, topdressing, de-thatching proponents.

I may share a current project I am experimenting with in
another thread but will need to weigh whether this is the right place or not
first.

Here is an example of phase 1 of my test taken on AUG 7, 2015.

"I should have known better than to attempt an open
discussion on this forum and don’t wish to hijack the OP’s thread any more than
it has been."

Thanks for the thought, but that sentiment would've been better had before you and dchall_san_antonio actually hijacked my thread. It was intended just to get a few simple answers. It was never meant to be an open discussion. Those are best had in your own thread started for your own purposes.

Byron,

The timing of aeration relative to the other processes is inconsequential. It has little to no impact on seed germination or turf establishment. If you decide to aerate in the Spring, it is best to do so before applying a pre-emergent. Otherwise you risk breaking the pre-m barrier.

dchall_san_antonio, thanks for the advice. I'd never really heard of the jar test. I'll have to see if I can dig up an old jar and give it a try. It sounds interesting. I say we have clay, one, because that's what the Ohio River Valley is known for; two, that's what I've always heard everyone, and I do mean everyone, refer to the soil as around my area; and three, from my experiences digging in it for one reason or another. Like you said originally though, it could just be really heavy, gummy soil and everyone calls it clay. I really do need to have a soil test done eventually, just so I know what I'm working with and what it needs. Until then though, the jar test sounds interesting. I'll try do do that before too long and post my results.

As far as aerating goes, I'm not definitely set on it or anything. I've done it a couple of times at another house I lived at in the past. It's just that everything I've ever read, before coming here of course, has just mentioned aerating like its a normal process everyone should perform on their lawn every year or two, especially in heavily compacted soil areas like mine.

As far as the dethatching goes, I've never done it before. I've never needed to. Chances are, I'll never do it again unless absolutely necessary. I know it tears up a lot of the turf in the process. The only reason I'm doing it now is because of the dense, heavy concentrations of mature crab grass I'm currently killing off. Just because it's dead doesn't mean it's going to just magically disappear. I seriously doubt that my grass seed is going to germinate through these heavy mounds of dead crab grass and we'll be way past fall overseeding time before this stuff rots away. I'm dethatching maily, hell, only to help get rid of that stuff to clear ground for the new seed I'm preparing to sow. After this year, hopefully, I'll never have to dethatch again. If I read up some more on the benefits of aerating and not aerating and take your guys' advice, I may not aerate either. That'll just leave overseeding every fall and I'm all for doing less work when I can.

>>>If I read up some more on the benefits of aerating and not aerating and take your guys' advice, I may not aerate either.

That's the best. Educate yourself and make your own decision. Lot's of unsupported statements or false conclusions get thrown around here from both perspectives and , as you've seen, it always devolves into a grade school grudge match.

As far as how low to mow, ideally, you want to mow low enough to ensure the seed gets to the soil and not hung up on existing turf and you want the existing turf low enough to allow the sun to shine on the emerging seedlings. About 1 1/2 innches should suffice and not create a lot of existing turf kill. You're going to need to maintain that height for a while. Hopefully, you can mow during germination without disturbing the seed bed or seedlings with selective mowing and/or delicate footwork.

Thanks yardtractor1. I'll be power seeding, so getting to the soil won't be an issue for the most part. I'm sure there will be a few areas, like around sprinkler heads and such, that I can't get too close to, and I'll need to hand seed but, for the most part, most of the seed should be in the ground. Also, according to the documentation, with optimum temperatures, which we should have at the time I sow, and constant watering, which it will have since I have in-ground irrigation, I should see germination in 5 to 7 days. Even if it's closer to two weeks, I should be able to make it that long without mowing if I mow down that low to begin with. Also, I mow with a walk-behind, not some big rider or ZTR mower, so it would probably be a lot easier on the seedlings.

Definitely the first and maybe the second time I mow after germination though, I may bag the clippings; something I never do. I've read that the clippings may drown out or cover the seedlings and keep them from getting the proper light, etc.