I will never mechanically aerate again after it brought up all the dormant poa triv and poa annua seeds!!!! I just use baby shampoo every couple of months

It punches holes in the yard and pulls up plugs that used to be in the holes. The idea is to open up the soil so air can get in. The soil surrounding the hole eventually melts and fills the hole as does the soil pulled out in the core. That newly melted soil must then develop a new structure where the roots and soil microbes live. Those new plugs sitting there on the surface may also contain old weed seeds which now see the sun and germinate.

Usually people core aerate to solve a hard soil issue. I don't think it works for that, because it does not address the issue causing the soil to become hard. There are two reasons why soil might become hard. One is compaction. Compaction results from repeated plunging of a tool into soil that is saturated with water. The tool plunging effect eliminates all the space between the soil particles. That space that used to hold air is now gone leaving a more brick like soil once it dries. This is how bricks are made. Even pretty good clay gets worked by hammering it and kneading it to remove the air that's "contaminating" it. You can see by the definition of how compacted soil is made that hardly anyone has compacted soil. If you park your car on the grass every day, even the days when it rains and the soil is saturated, then you could compact the soil. Core aeration may address a true compaction problem. The second reason why soil gets hard is the beneficial fungi that live in the soil become depleted from lack of food, water, or environmental stress (fungicides, extreme heat, flooding, or other chemical exposure). This happens a lot. About all you have to do is abandon the yard for several months so that it dries out and that will do it. These fungi like it when the soil is relatively consistently cool and moist. You can cause that to happen, and the fungi will return to soften your soil. Core aeration does not address this.

If you are familiar with the green fungus that gets on bread, you might be able to relate to the fungal effect in the soil. If you have bread in a bag, or even just in a moist spot, it will develop green spots. Let those go a few days and the spots become hairy with fungal hyphae. If the bread is in a bag, the hyphae will fill the bag in a few days. The same thing happens in the soil when it is the right temp and moisture. That's what the shampoo helps with. It allows the water to penetrate very deeply into the soil. That moisture helps keep the soil temp consistent for longer and through the various depths. The fungal hyphae fill the soil with invisible strands of fungal material. When the soil becomes moist, the hyphae expand and push the soil particles apart. When the soil dries out the hyphae shrink back away from the particles leaving a capillary channel for air to penetrate the soil. Those channels also allow moisture back down into the soil when it gets wet. And when it's wet the soil pushes around when you walk on it.

Many years ago some surfactant products came on the market to soften hard soils. At $70 per gallon they were beyond the budget of most hobby gardeners. But they do work. Since then it has been discovered that just about any surfactant will do the same thing. At first I think they used liquid dish washing soap but nowadays those have bacteriacides in them. We don't want that. Instead we have taken to using shampoo. The application rate is 3 ounces per 1,000 square feet. You cannot go wrong by doubling, tripling, or even using 10x too much. Spray it on and follow up with 1/2 to 1 inch of irrigation or rainfall. In 3 weeks the soil should be noticeably softer. You can test it with a screwdriver. Push a screwdriver into it now, when moist, and 3 weeks after the shampoo. It should be much softer. Mine was sprayed in 2012 and it still is almost too soft to walk on...when wet. This works and is noticeable when it's wet. When the soil dries out between watering, it should become hard again. It's just like a sponge is hard when dry and soft when wet.

That's as much as I remember right now. I'll never core aerate my yard.

Golf courses would not do it all the time if it did not do anything. They have carts driving on them and constant foot traffic, so they are more prone to compaction and need it. The bigger question is do you NEED it? That's up to you. It won't hurt at all if you do.

Golf course have golf carts driving on them all the time. Tires create massive compaction on 4 very small points (tires). All of the weight is compressed onto 4 small points. Very effective for when you want brick solid dirt in certain locations (new roads etc). I believe that is called mechanical compaction. I would aerate for that, if you don't want it.

Does your yard have mechanical compaction?

Most of those who irrationally disclaim aeration neither understand it nor know how to properly employ it. Use of a surfactant (shampoo) has limited benefit/use (counteracting hydrophobic soil surfaces, and reduce water pooling/puddles) and will do nothing to aerify detrimentally compacted soils. Surfactants adversely impact capillary function. How is that good for grass plants? The lubricating effect will improve your ability to stick a screwdriver into your soil with ease. A parlor trick. There is no evidence (study) that shows an increase in weed proliferation due to aerification. Are the lawns of your neighbors who aerify full of weeds? If so, they were full of weeds long before aerifying. There will always be those who prefer to eat their broth with a fork and reject the spoon. That is their right and fine by me.

For warm season grass yes Bermuda and zoysia etc. It turned out to be terrible for me on fescue. Reviving a rough lawn it produced a bad clumpy mess where seeds fell.

I did an experiment this year. In a bare area of soil --- where NOTHING was growing --- I did a core aeration in one small area and i left the rest as it was. I broadcasted some grass seed.

The areas that I aerated, the grass is lush and beautiful. The other areas, literally inches away, are pathetic.

All things were equal; water, sunlight, Milorganite, etc. This area has zero foot traffic.

Core aeration works, at least for establishing a lawn. But you don't have to take my word for it.

Here is another shot of the area taken about 1 month before the other two. You can see that the plugged area is performing well in comparison to the adjacent areas.

Here is the same area again before any grass seed was broadcast.

Are those grass plugs or grass seed growing out of the aerate holes?

Seeds growing out of the holes. That's why I never aerate before seeding, I use a verticutter.

I love these aeration argument threads!

The working hypothesis I am operating under goes like this: Soils that are biologically healthy do not need aeration. In fact, aeration would be a negative thing for such a soil. On the other hand, if the soil is under distress from less-than-ideal chemistry and nutrition then aeration appears to help temporarily.

To put it another, slightly more blunt way -- if you have to aerate then you're doing something wrong.

Also, BTW there is photographic and anecdotal evidence that core aeration can cause germination of weed seeds if you look around the internet long enough.

I forgot about anecdotal evidence:

Here

Keep that strap on your tin hat snug.

Grass seed, not grass plugs.

Re: you don't need aeration if you have healthy soil

In my experiment, the soil was identical. Literally, the only thing that was different was the plugs made by the aerator.

Look at the second photo I posted. You can already see where the plants that developed in the holes are filling out and coming together.

Had I aerated the entire strip where I seeded, the entire area would be extremely nice stand. Especially if I had use a power aerator rather than the manual aerator, which would have produced more uniform plugs in the soil than I did with the manual tool.

Re: aeration exposed weeds.

The areas in my experiment that did NOT receive aeration have plenty of weeds coming in.

(Those areas will look like lespedeza city come summer, believe me)

The areas where I did aerate, however, have zero weeds coming out of the holes and hardly any in between the holes by comparison.

(Probably because the turf that is growing from the holes is tall and able to shade out the weeds...)

My conclusions from this experiment:

Core aeration is a great way to START growing grass from seed in a barren area.

My hypotheses from the experiment:

The plugged holes provide optimal seed to soil contact, resulting in improved germination. These plants established faster because the holes protected the seeds from drying winds and/or temperature.

Water (rain, sprinklers, hose, rtf.), organic matter (e.g. Grass clippings, shredded leaves), food (e.g. Milorganite, Starter Fertilizer) and amendments (e.g. Lime/Mag-I-Cal) will find their way into the holes, helping to nourish the plants and keeping the root zone moist.

By starting life in the holes, the plants have a head start on digging deeper roots. The plants thst started in the surface/not in holes gave a harder time finding moisture and nourishment.

I will continue to monitor this area to see how the plants survive this summer. If the plants that started in the aerated holes survive and the other plants continue to struggle, I will do the experiment again but with a larger aerated area.

Yard quips: Keep that strap on your tin hat snug.

Who's the troll now? :P

Call me part of the tin hat brigade, but what's wrong with making sure your soil quality is up to speed before doing extra work like aerating? For that matter, why didn't you ask the OP if he had a soil test? Why didn't you ask him what his Mg levels were? I know you know what high levels of Mg and/or Na will do, so why not start with that instead of a band aid cure like aeration?

The other perplexing thing is that none of the "pro aeration" people answer this question: If there is one person, just one, who has a fantastic lawn and never aerates, don't you wonder why they don't have to?

Yard, I know you are a dead-ender, but I think maybe j4c11 might have learned some things he didn't know before... maybe, but it's a start.

owl said: The areas that I aerated, the grass is lush and beautiful. The other areas, literally inches away, are pathetic.

I applaud you for actually doing some experimenting to gain better understanding. I wish there more of that and less pontificating.

Having said that, I believe there is something wrong with your methods. The main thing that glares out at me is the fact that you were not able to germinate seeds in the areas not plugged. This says that you did not provide something needed for germination, be that enough water, good soil contact, protection from birds, and so on. It could simply be that water migrated to the holes and provided the moisture that the rest of the ground wasn't getting, or maybe birds ate a lot of the seeds on the surface and not in the holes. My point is that the results would have been more interesting if you were able to germinate and grow the grass everywhere the way we know it can easily be done. Also, what happens when the hole closes up? How much of that grass is growing out of the hole, and how much is just near it?

Yes, aeration works to relieve surface compaction. Surface compaction occurs during the course of the year due to rain, gravity and foot/mower traffic. It also gives you a way to incorporate soil amendments rather than just laying them on the surface.

There's one study that claims organic matter acts to reduce compaction, but there's no evidence that the 4-5% organic matter content found in the average lawn makes any kind of significant difference.

The quip was a reference to the general value of anecdotal evidence, not necessarily an attack on you specifically. However, I kinda like the idea of the tin hat brigade. Maybe I'll start giving the "tin hat" award for the most poorly supported/irrational statement of the day. :-/

Most of those who irrationally disclaim aeration neither understand it nor know how to properly employ it.

I realize that you're just repeating what you read here or possibly a couple of other lawn sites (like playing telephone). That you likely have no actual experience with aeration and haven't bothered to analyze the process. I do acknowledge that you have expanded your knowledge in a number of areas regarding turf and soil- you just summarily dismiss aerification by word of mouth of other inexperienced individuals.

Before proceeding, as you appear intent to have this discussion, let's address some inaccurate assumptions:

First, that aeration is recommended as a continuing maintenance task like mowing. Something to be done on a schedule for as long as you own a lawn. Unless, of course, you are hosting weekly athletic events, It is not, despite what people with a magnetic sign on their pick-up truck might say. It is employed by people who understand aerification and its proper implementation as a tool uniquely adept at assisting in achieving specific outcomes.

Secondly, that compaction occurs only when soil has been subjected to exceptional circumstances to which homeowner lawns are not commonly subjected. e.g. golf carts, heavy equipment, animal or people herds, etc.

This is not accurate. Compaction is simply the reduction of space between solids. All soils compact due to the forces of nature (gravity and the percolation of water). In addition, the first time that as little as four pounds per sq inch of pressure is applied, it can result in 70% of maximum soil compaction. Some state of compaction is natural for soil. It becomes a problem when it is detrimental to turf health or soil structure. Compaction in silty or clay soils is much more likely to have a detrimental effect than sandy or well aggregated (floculated) soils.

Third, that aerification causes weed seed to germinate. Is that possible? Anything is possible but possible does not mean probable. There is no evidence that this is a problem. If it was, I would expect it to be noted by university turf researchers or turf specialists, both of whom freely advise the use of aerification. Considering the number of people that aerify, wouldn't you expect to see a lot of negative comments in the forums if aerifying resulted in any significant increase in weeds? Consequently, in my opinion and one evidently shared by many turf specialists, the benefits derived from properly employed aeration outweigh the chance that some long dormant seed may be germinated.

Fourth, that aerification is not beneficial for seeding. This is one where I have allowed my common sense to control. How could seed that falls into a hole possibly germinated? Although I've seen pictures of germination on the edge of the hole, I've always advised against it. Owlnsr's pictures are... stunning. I'd want to see those results repeated in other lawns and although not a particularly desirable outcome for a non spreading grass like fescue, it would be a perfectly successful outcome for establshing a stolon or rhizome spreading turf. Now I see why turf specialist commonly recommend aerification and seeding into a poa a or poa T stand to slowly eradicate them. Regardless, I think slit seeding gives more consistent, uniform results. Kudos owlnsr and thank you for doing that test and posting pictures.

Lastly, that aerification is nothing more than making holes in the soil. The action of the fixed tine as it revolves around the axle fractures the soil for a considerable distance behind the hole. The fracturing is what gives newly aerified soil that spongy feel. Same affect as when using a fork spade.

j4c11 wrote:

Yes, aeration works to relieve surface
compaction. Surface compaction occurs during the course of the year due
to rain, gravity and foot/mower traffic...

Can you look down at your lawn and actually see soil for rain drops to hit? If so you've got bigger problems than whether to aerate.

There's one study that claims organic matter acts to reduce
compaction, but there's no evidence that the 4-5% organic matter content
found in the average lawn makes any kind of significant difference.

Funny how you make reference to the article I provided to you, agreeing with the parts you like, and disagreeing with the parts that contradict your previously held beliefs... not only that, but taking statements way out of context.

I have to take back what I said earlier about some people learning new things. :o(

yard said: Maybe I'll start giving the "tin hat" award for the most poorly supported/irrational statement of the day.

Maybe you should get some of j4c11's big tuna cans and make it a tuna hat award. I figured somebody was going to misunderstand the value of anecdotal evidence. Congratulations on being first! I'm not going to 'splain it.

Regarding your post above, you need to start by convincing j4 of these things. I don't think you guys are on the same page. Also, I started replying to some of your statements and stopped myself. I'd be more interested in answers to these questions from you:

1. What is your background in lawn care?

2. Do worms aerate soil?

3. Why do some people have incredible lawns yet never aerate?

4. What evidence is there that fork tines "fracture" the soil and make it feel spongy?

5. If sandy soils are far less likely to require aeration than clay soils (according to you) why do you never inquire about someone's soil when they want to know whether to aerate in the spring or the fall?

6. Show me something I've written that is irrational, please.

Thank you for your indulgence. Answers are due by Sunday morning for full credit.

No, I agree with all of it, I'm repeating what it said word by word. You provided it, you said it's from reputable agronomists and applies to lawn care. Your article said that rain, gravity and traffic cause compaction. Your article said that organic matter prevents compaction if one particle of organic matter is attached to a particle of soil. Nowhere does it say that 5% organic matter is sufficient to prevent compaction in any significant amount. If you have any additional data to add that would lead to that conclusion feel free to provide it.

3. Why do some people have incredible lawns yet never aerate?

• Why do some people have incredible lawns yet never water deeply and infrequently?
• Why do some people have incredible lawns yet never use organics?
• Why do some people have no tooth problems but never brush their teeth?
• Why do some people have great health but never go to the doctor?

Hopefully you now understand why that question you keep asking is meaningless.

Regarding your post above, you need to start by convincing j4 of these things.

I already agree with all the statements he made.

j4, with all due respect, there is a saying that applies here: you are "not even wrong."

j4, with all due respect, there is a saying that applies here: you are "not even wrong."

Or in other words:

1. What is your background in lawn care?

Smart question. Always familiarize yourself with your opponent. I have no formal education in agronomy, turf or soil science or microbiology. Just a lot of decades mowing the lawn.

2. Do worms aerate soil?

The big invasive European night crawlers or the skinny short grey ones that get on the sidewalk after it rains?

3. Why do some people have incredible lawns yet never aerate?

They have, at worst, silty sand, they sodded, and their lawns are only 2 years old?

4. What evidence is there that fork tines "fracture" the soil and make it feel spongy?

That's akin to explaining an orgasm and how it feels to a person who has never had sex. Spade forks were the original aeration tool. Aerating machines were designed to simulate the same action and results. Do your own experiment. Borrow a spade fork and find a piece of earth that you don't care about (like a neighbor's yard) Using it like a shovel, insert it vertically/perpendicular into the soil 6" deep, pull the handle towards you so that it is 30 degrees from vertical. Pull it out of the ground and repeat the process every 4-8". Walk on the soil. That's what spongy is due to the forks fracturing the soil, if you have another reaction, that does not mean aeration is sex.

5. If sandy soils are far less likely to require aeration than clay
soils (according to you) why do you never inquire about someone's soil
when they want to know whether to aerate in the spring of the fall?

Don't misquote: "Compaction in silty or clay soils is much more likely to have a
detrimental effect than sandy or well aggregated (floculated) soils." That's another inaccurate assumption I forgot to address. That the sole purpose of aeration is to relieve compaction. There are other, equally, important purposes.

6. Show me something I've written that is irrational, please.

Everything is about you? Careful or there won't be a tin can big enough to fit that ego. Be assured, you'll be in the running for the tin hat award the next time you say something inaccurate, foolish, unsupportable, irrational or just plain stupid.

Do you have an inquiring enough mind to meaningfully contribute to a discussion? You can do better.

Edit: On anecdotal evidence. I've presented you a plethora of anecdotal evidence on alien abduction. Based on the value you place on anecdotal evidence, I suspect you are now a firm believer? or maybe you always were.

I expect at least partial credit.

j4: Hopefully you now understand why that question you keep asking is meaningless.

You're not even curious. Why are you afraid to consider alternatives to the aeration dogma (fluff pieces with no scientific backing, not even a study like what owl did above, do not suffice as evidence)? I'm not 100% sure either way, and I've stated my position on the subject plenty of times before, but the evidence I see says there is no need to aerate unless for some extreme circumstance. I have no dog in this fight.

Well, there's people that, based on the evidence they see, think the Earth is flat and stationary. Everyone else that thinks the earth is round is just afraid to consider the alternative. All evidence to the contrary of their firmly held beliefs is insufficient or fabricated or a government conspiracy. Sound familiar?

Bottom line, all you have to do is look at what the people with experience and education in the field are saying. While I understand that you probably demand a complete molecular biology study from your doctor before you take any pill prescribed, just to make the evidence is there, here's some fluff pieces from every state university in the country on the matter:

http://www.ext.colostate.edu/ptlk/1505.html

http://www.ipm.iastate.edu/ipm/hortnews/2005/6-22/lawnaeration.html

http://www2.ca.uky.edu/agcomm/pubs/agr/agr54/agr54.pdf

http://www.ext.nodak.edu/extnews/askext/lawns/1522.htm

http://plantscience.psu.edu/research/centers/turf/extension/factsheets/aeration

http://www.clemson.edu/extension/hgic/plants/landscape/lawns/hgic1200.html

http://learningstore.uwex.edu/Assets/pdfs/A3710.pdf

... you can google the rest to 50.

Now, which is more likely, that hundreds of trained and experienced agronomists from every state in the country are wrong, or that the guy with no training or experience in the matter is wrong? My money is on the latter.

j4: I think we've lost track of what I am saying here. All of your links say that lawns compact and aeration is needed to correct the compaction. At least one of your links, the one from Clemson, says that if you can plunge a screwdriver down into wet soil without difficulty, then you don't need to aerate. All I'm saying is that from what I have researched and learned over the last 3 years, it appears to me that there are better ways of maintaining a lawn than merely by applying WW2 era inorganic fertilizers and calling it a day. People are continually learning better methods. If my lawn magically compacts itself to the point that I can't put a screwdriver into it when wet, then I'll try to figure out what went wrong. I know you can put a screwdriver down 6" into your lawn because that is how you figure out when to water. So why are you aerating? Is Clemson wrong?

I'm not sure what your point is with the "WW2 era inorganic fertilizers". We still eat the same food and drink the same water from 100,000 years ago, so what? Nutrients are nutrients. By the way, your organic fertilizers still have to be converted to an inorganic form before a plant can take the nutrients in.

Now you're being disingenuous. The word used in the article is moist ,not wet. Hopefully you understand the difference between moist and wet, if not I'll be happy to explain. Testing the soil immediately after irrigation would be pointless, it's full of water and the screwdriver will penetrate any soil that's waterlogged. A moist soil to me is 24 hours or more after irrigation. 95% of people are not going to be able to easily get a 6 inch screwdriver into the soil 24 hours after irrigating.

j4: A moist soil to me is 24 hours or more after irrigation. 95% of people
are not going to be able to easily get a 6 inch screwdriver into the
soil 24 hours after irrigating.

OK, fine. Let's go with "moist." So, just to be clear, are you saying you can't poke a screwdriver into your soil when it is moist? Also, I'd bet almost any amount of money that somebody who can't pass the screwdriver test before aeration still won't be able to do it after aeration.

Actually the food and water we drink is vastly different from what was consumed 100,000 years ago. The point is that people learn to improve on methods, including lawn care, over time. A car in 1916 isn't quite as good as one in 2016.

Last point. Be careful about listening to "experts" who parrot conventional wisdom. Yes, if your lawn isn't cared for correctly maybe aeration does something, maybe not. I called a seed guy last year for some extra low weed content seed. This guy grows sod on his own property and has forgotten far more about growing sod than I'll ever know. He's around retirement age. We got to talking and I told him that I have a large hickory tree and I mulch the leaves in. He nearly jumped through the phone and strongly recommended that I not do that. He said hickory leaves were far too fibrous for the lawn to break down and the leaves would choke out the grass. Well three years on, and the grass is growing beautifully near this tree with no sign of mulched leaves anywhere. I think we are learning better ways to create healthy lawns, more biologically active lawns, that can handle lots of things thrown at it.

I started aerating 2 years ago twice a season in spring and fall. I also start using a local biosolid/sewage sludge. I just aerated yesterday making it the fith season I did so. Each time I also walk around and throw seed by the handful to help get it into the little holes. I can say this. My lawn has looked the best it ever has and I can see lots of new grass coming in each year. I can't say for sure if it's the aerating or the sewage sludge. I also mulch mow except for fall when too many leaves and I can't mulch them fast enough. In my opinion aerating cannot hurt.

Also, I'd bet almost any amount of money that somebody who can't pass the screwdriver test before aeration still won't be able to do it after aeration.

So what? Aeration is not about poking a screwdriver in the soil or passing a screwdriver test, it's about relieving compaction. You can dump a bunch of baby shampoo in the soil and stick the well lubricated screwdriver as deep as you want. Doesn't mean there's no compaction anymore. The reverse is also true, if you aerate and still can't stick the screwdriver in, doesn't mean a good amount of compaction hasn't been relieved. It means you could probably benefit from doing it again the following year. The author of the article used the screwdriver test as a rule of thumb not as a goal to achieve in itself.

So, just to be clear, are you saying you can't poke a screwdriver into your soil when it is moist?

No, not at all. I tested yesterday and I am able to go 6 inches into moist soil. 3 years ago I'd get stuck around 2 inches . Aerating every year for 3 years obviously helped. I will probably skip this year.

The point is that people learn to improve on methods, including lawn care, over time. A car in 1916 isn't quite as good as one in 2016.

People also come up with bogus claims and quackery. I'll take a 1916 aspirin over a 2016 homeopathic "remedy" any day. New doesn't necessarily mean improved.

Actually the food and water we drink is vastly different from what was consumed 100,000 years ago.

Water is not H20 anymore?

Be careful about listening to "experts" who parrot conventional wisdom.

Cool story, but following best practices agreed upon through scientific consensus among a community of hundreds of experts is not the same as listening to what some guy told you on the phone.

So there you go, Kevin. Some people think it works, some don't. Both sides agree that the other side doesn't know what they're talking about. Give it a whirl and if it works or doesn't work for you, please let us know.

If you search the real scientific literature you'll find the same arguments for and against.

In response to danielj_2009:

I applaud you for actually doing some experimenting to gain better understanding. I wish there more of that and less pontificating.

Thanks. I typically like to see how things work for myself, and this is what I was doing. Just wanted to offer the results I had.

Having said that, I believe there is something wrong with your methods. The main thing that glares out at me is the fact that you were not able to germinate seeds in the areas not plugged.

Well, I was able to get grass to germinate in the areas that were not aerated. They are still living, but they are quite thin and frail.

This says that you did not provide something needed for germination, be that enough water, good soil contact, protection from birds, and so on.

I had germination everywhere. However, the seed thst germinated in the holes established quicker and stronger. Meanwhile, the seeds that did not germinate in the holes are struggling. I do not expect them to last through the summer, but I am not particularly worried as this was an experiment.

It could simply be that water migrated to the holes and provided the moisture that the rest of the ground wasn't getting, or maybe birds ate a lot of the seeds on the surface and not in the holes.

Yes, this is one of my observations: the holes provided a better environment and conditions for the newly germinated seeds. This is the main reason that I believe the plants that the germinated in holes are thriving.

My point is that the results would have been more interesting if you were able to germinate and grow the grass everywhere the way we know it can easily be done.

Again, I was able to get turf to germinate and grow. But it's not growing very well. I believe the reason is the holes provided a better environment for the germinated seeds.

Also, what happens when the hole closes up?

The holes have been closed up for quite some time. It seems they have filled in with organic matter (shredded leaves from the fall, most likely) and probably some of the soil thst was on the edge of the holes. The plants are thriving.

How much of that grass is growing out of the hole, and how much is just near it?

The turf thst you see thriving is what grew from inside the holes. It was Jonathan Green Black Beauty Ultra, so it's predominantly TTTF with some KBG and PRG. I believe I have already seen some of the KBG starting to spread.

The purpose of my experiment was to see the differences between growing grass from seed in aerated holes vs. broadcasting. No other prep work was done other than core aerating a small area, and all other things (watering, foot traffic, sunlight, feeding, etc.) were equal. With all things being equal, I found that the aerated holes provided a superior environment for germinating, supporting and establishing grass from seed.

I'm going to follow dchall's lead and just say, "aerate your heart away if it makes you feel good." That's pretty much what everybody else says. "Do it if it works for you" I think is the usual reply.

I do have to address something j4 said above: Cool story, but following best practices agreed upon through scientific
consensus among a community of hundreds of experts is not the same as
listening to what some guy told you on the phone.

You have to be very careful when talking about "scientific consensus." Do you believe the 100 experts did their own independent aeration studies, or do you think it more likely that they do it because it seems to help and that's what everybody else does? What if my "hickory leaf expert" told 20 interns the same thing, who then went on to open their own businesses? If 10 of them said that hickory leaves are bad for your soil are you going to call me a dingbat for contradicting 10 experts?

In a nutshell, "consensus" should have limited power to convince anybody. The more important question is what REAL studies have been done, do they follow good scientific practices, have they been peer-reviewed and/or duplicated, and what do those studies say? Here's an interesting example. I haven't read the full paper, but the jist of it is that humus does not exist as previously thought for the last 200 years... that's a lot of experts, j4!

http://www.nature.com/nature/journal/v528/n7580/abs/nature16069.html

It is a mistake to believe that scientists are somehow morally superior and are immune to bias any more than the average guy on the street. Many times all you have to do is follow the money when it comes to research funding.

I haven't seen many/any real aeration studies for a lawn at home, not a golf course. Maybe dchall has. I'd be interested to see them.

The other day I was in the yard and a nice older lady came walking by. We talk about lawns whenever I see her and we strike up a conversation. I said I had some small bare spots, possibly from dumping too many leaves on the lawn last fall, or maybe from a bit of a drought we had. I didn't mind because I wanted to improve soil structure and it'll fill back in anyway. So she says, "Oh take a pitch fork and stick it in the ground where the bare spots are. The roots will be attracted to the oxygen and it will grow in better that way." I had a good laugh that I'm getting grief not only from anonymous nuts on the internet, but from nice old ladies, too! BTW, the bare spots are filling in quickly it seems, even without the pitch fork. lol.

I hesitate to bring the following up because I don't want to alienate anybody in this forum, but I believe the mother of all examples of this sloppiness about science through consensus is global warming aka climate change. I know far more about the subject than anything to do with lawns, but this isn't the place for it. PM me if you dare! lol

owl: regarding the following and your other comments above: I had germination everywhere. However, the seed thst germinated in
the holes established quicker and stronger. Meanwhile, the seeds that
did not germinate in the holes are struggling. I do not expect them to
last through the summer, but I am not particularly worried as this was
an experiment.

I'm at a disadvantage because your description of the seeding was a bit vague. Did you seed in the fall and over-winter, or did you do it just recently. Do you live in a warm region or cold? I'm just asking because you say you got germination everywhere, yet in the photos it looks like you have nice plugs surrounded by bare earth and weeds. Not knowing any better, it really looks like you put down premerg, then poked through that with holes! I know you didn't do that, though.

There are still two things that bother me. One is that although you say you got germination everywhere, I really only see weeds. It looks like you haven't given the non plugged areas a fair chance. It's like you deprived the ground of sufficient water so that only the grass near holes could survive, like an oasis. To me, this doesn't necessarily say plugging helps, it just says that you need more water and then the entire area will look like the plugged holes. The other potential issue is whether you have too much seed in the plugged holes. I'm not trying to act like an expert on the subject (I'm not) but I do know it is important not to put down too much seed as most people tend to do. Have you given any thought to this?

I'm not sure if I am making my point or not. I'm not trying to be over critical. I like what you did and wanted to understand more. Think of it this way: Let's say you provided warmth, light, moisture and nutrients ideal for growing new grass. You should have had a nice thick carpet of new grass in the entire area. In such an example you may have found no grass at all growing from the holes because, maybe, the holes would have been water logged and not a good place for germination. You conclusion in that situation would be that aerating is bad for new lawns. This is why the apparently poor germination outside the holes bothers me.

I appreciate your curiosity but I truly think you are overthinking this.

All things were equal except for the holes.. I have done nothing except broadcast the seed (and some Milorganite at the time of seeding) in early spring. No preemergent or anything was applied.

No human intervention after seeding. No watering, babying, spoon feeding, singing to it at night, etc.

Nature decided that grass that did not germinate in the holes is weak, thin and stunted. Some of the areas are doing "ok" but overall It is started to get crowded out by weeds.

Nature decided that the seed that developed in the holes is thick, strong, and is starting to spread,

I have no doubt that if I had babied the grass that didn't germinate in the holes, I could have had better results. However, I wasn't trying to establish a lawn I was performing an experiment.

It seems that just broadcasting the seed doesn't work very well unless there are some holes for it do fall into.

It also seems that seed that falls into aerated holes needs substantially fewer care to develop - no mulching the top layer with peat or straw; no light watering every day; etc. etc.

Owl,

whats the green mossy looking stuff in the first 2 pics? It looks like that hydroseed mulching stuff? In the area that is not areated did you do proper seed germination prep? Or just toss?

owl: I have no idea what you are talking about! I'm thoroughly confused. I said earlier it would have been more interesting if you were able to get grass to germinate everywhere. You replied more than once that you were able to "get" grass to germinate everywhere, just not as strong. This implies you were watering and trying to get the whole area to grow. Then you say you just threw seed out there and let nature take its course. I asked about the aeration holes closing up and you said they already closed up from leaves and whatnot last fall. But you said you seeded this spring. Which is it? Did you aerate and seed in the fall, aerate and seed in the spring, or aerate in the fall, let the holes fill in with leaves and then seed in the spring? I think it make a difference which one you did to really understand what is going on.

Sorry if I am over thinking... :op

I don't think that picture proves that "aerating works by relieving compacted soil." all it proves is that if you poke holes in your lawn and drop seeds in there it will more likely germinate.

if that soil was relieved of compaction through the aerating process, then that general area should have good germination, not just the holes.

hell, ill even go as far as its a picture rigged to sell aerating services to the unknowing.

Kbinmd:

- Are you talking about the last photo? There is moss in the far right background near the road. That is on the neighbors property line with mine. In the foreground if that same photo, there are some grass clippings carrying the mower bag over to a compost pile. In all the other photos, I believe you would be seeing the grass that germinated on the soil (not in the holes). There is also lespedeza sprouting in the photos.

- Nothing It was done to prep the seed bed. This was an experiment to see what happens when broadcasted seed lands on the soil vs lands in aerated holes.

Daniellj_2009:

- Yes, germination did occur everywhere. No human intervention. But the germination rates were not as high and the plants are extremely weak (Not as strong/not well established). Most of that is being crowded out by lespedeza; however, the plants that grew in the holes are not getting any pressure.

- The holes closed naturally. organic matter such as mulched leaf clippings from the fall seem to have filled in the holes. I'm sure some that some of the soil slid into there as well after a rain. This is all speculation; I don't know for certain because there was no human intervention (other than milorganite applied at seeding). All of this was done in early spring.

again, it's quite simple: with all things being equal, the seed that grew in the holes produced superior plants than seed that didn't fall into the holes.

I am just presenting the results of my experiment. By accusing me of doctoring up a photo to sell aeration services, you come across as some kind of crusading anti-aeration ideologue. Good day.

-Green Machine:. Compaction was not within the scope of my experiment. That entire area (aerated and not aerated) doesn't seem compact to me at all, actually. It doesn't get any foot or machine traffic.

The photo does provide anecdotal evidence that aeration holes provide a better environment for growing grass from seed in an otherwise plantless area on my property. I don't know if the same results should be expected on someone else's property. More experiments like this would be needed. Would be interesting to see if we could get a few different folks to do this as part of a long term study.

There's no doubt in my mind that aeration holes are the perfect germination environment for grass seed. Perfect seed to soil contact and constant moisture make them perfectly suited for the task, has nothing to do with compaction. The reason I don't use core aeration for seeding purposes is that many seeds can drop or wash into one hole which would end up in a very clumpy look, as pictured. What's best for the grass seed is not necessarily what's best for obtaining a uniform lawn.

owl huffed: I am just presenting the results of my experiment. By accusing me of
doctoring up a photo to sell aeration services, you come across as some
kind of crusading anti-aeration ideologue. Good day.

I'm on your side. I'm the guy who congratulated you for doing an experiment. Green Machine is the one who said that, so you might take issue with him instead.

I know you didn't intend to write a doctoral thesis about what you did, but the way you presented it left a lot of questions that needed to be answered in order for your experiment to be of any use to anybody other than you. I'm with j4 in that I'm curious whether you've got too much growth at the holes. How does the grass even grow at the hole anyway? If seed is too deep the closed hole will cover the crown and the grass will die. So how many plants are growing off the edge of the hole? You could probably even count them. These are all rhetorical questions. If you are so inclined, you could consider starting a new thread describing your experiment a little more formally and with the photos. State the kind/blend of grass, etc. You could add additional photos as things develop. Does the plug thin out and die over time? etc. etc.

Nice to see this discussion instead of back and forth rants. Nice change!

I get the impression that the seed was not rolled down or walked on like I always suggest. That suggestion comes from the grass farming industry (ranchers). Some observant ranchers have noticed that when they scatter seed after animals have left a pasture, they will find improved germination in areas where wild animals have come in and stepped in the pasture. They saw footprints with growing grass in them and stunted or no grass adjacent to the footprints. In order to improve their process they started scattering their seed before moving the livestock out of the pasture, so the livestock will trample it all down onto/into the soil surface.

Right? They were just using up the internet & wasting keystrokes for a few days there...

I had my lawn core aerated a good 20+ years ago and the plugs left over are not easy to deal with. What is the best way to break them up? Do the spike aerators you pull behind a lawn tractor work well enough that I don't need the dog turds? Is compacted soil a cause of my constant fungus problem? It shows itself in July when it get s very hot here.

Danielj_2009:

My bad. That's what I get haha. Next time, I need to double check before huffing lol.

We have been getting a fair amount of rain here over the past week or two. I think I'm started to see some of the weaker looking turf perk up.

I will snap some more photos in a few days. I will try to get angles thst match the pre-seeding photo that I posted.

niziurski53, please open a new topic for your issues. Yours is not likely an aeration issue, so if you ask it here, first you are hijacking this topic, and second, nobody will look here for your question and resolution. When you do post, please tell us where you live and what kind of grass you have. We may have more questions, but that will get you started.

owl: I will snap some more photos in a few days. I will try to get angles thst match the pre-seeding photo that I posted.

Let me make a suggestion. Start a new thread and paste what you've already written in the new thread and then add more to it as time goes on. You can save the thread in your "favorite places" so when you want to add to it in 6 months it will be easy to find. That's what I do with my soil results threads so I can refer to them the next year.

adam said: Golf courses would not do it all the time if it did not do anything.
They have carts driving on them and constant foot traffic, so they are
more prone to compaction and need it. The bigger question is do you NEED
it? That's up to you. It won't hurt at all if you do.

and newtolawncare said: Golf course have golf carts driving on them all the time. Tires create
massive compaction on 4 very small points (tires). All of the weight is
compressed onto 4 small points. Very effective for when you want brick
solid dirt in certain locations (new roads etc). I believe that is
called mechanical compaction. I would aerate for that, if you don't want
it.

Golf courses are very different from home lawns and you can't say that since a golf course superintendent does it, that you should also do it at home. They aerate not just for compaction, but for organic build up over their sand base. Here's an interesting short article on a guy backing away from aeration at golf courses:

http://www.turfhacker.com/2015/04/core-aeration-thing-of-past.html

I found this passage from the article particularly interesting given our discussion here:

I have never core aerated our fairways, they are on native soil/rock
and see a lot of cart traffic. I just let the worms do the work for me.

A fairway is a heck of a lot closer to a home lawn than a green is.

"Some people" in this forum look down their noses at worms as little aerators. I don't know why but would love to learn how it is that worms are not effective. I actually mean that sincerely. I'm not a worm expert but I think they do travel through soil and roots and poke up through the surface. How is that not aerating? A little googling shows an amazing number of benefits to having lots of worms (ie, feed organically). I trimmed the edge of my lawn today and probably saw one worm every couple of square inches, and that's at the edge up against the curb. If one square foot equals 144 inches, I could have conservatively 25 to 50 per square foot, or 25,000 to 50,000 worms in 1000 sf!