Aerating A Lawn With A Lawn Core Aerator? Follow This

Aerating A Lawn

Just like lawn dethatching and lawn rolling, I can see why people might think aerating a lawn with a lawn core aerator is necessary on an annual basis.

Not only is it often recommended gardening advice, but most lawn care companies do this as part of their regular service, organic gardening companies included.

The thing is, it can be beneficial if done right, but it generally isn’t done right, so I’m going to give a few lawn aeration tips here.

Aerating a lawn involves cutting round holes in the soil with a lawn plug aerator and pulling the core out. It can be a good thing, but only if followed by another important practice.

As an important aside, there is another method called spiking that makes holes in your nice organic soil without pulling any soil out. You may have seen those shoes with spikes on the bottom you can wear while walking on the lawn. This method is useless because although it is creating pore spaces in the soil, it is compacting the surrounding soil. Soil must be pulled out to get any benefits.

So onto the lawn aeration tips…

Aerating A Lawn – What Is The Purpose?

The reason lawn aeration with a lawn core aerator is generally done is because it is thought to increase air and water penetration into the soil.

While these are important organic gardening goals and it works for a very short time if enough cores are pulled from the soil, the effects are short-lived.

Here are the 3 biggest downsides:

1. When the holes fill back in with the dead grass and soil that was pulled out, it can cause water issues. But more commonly the holes are backfilled with sand, which may cause major water problems, with patches of dry grass and patches of overly wet grass. This happens when sand is mixed into your soil that is a different texture.

2. The grass is physically hurt by the lawn core aerator and if done regularly, the grass health can be greatly affected. Of course, the microorganisms are effected, too, especially fungi, which are integral in organic gardening practices for the health of the lawn. Regular aeration can severely decrease their population.

3. If you are aerating a lawn during late spring or summer when the grass is directing most of its energy towards top growth, it will be forced to switch back to root growth to repair the roots that have been cut. This is very bad for the plants.

When Is A Lawn Core Aerator Necessary?

Aeration should not be necessary on an organic lawn that is healthy, but while you are in the process of transitioning your lawn to be healthy and perhaps moving to organic gardening methods, it can be very useful to create a healthier, less compacted soil environment and a denser, healthier root system.

All this will happen only if the tines are sharp, if the machine actually pulls cores out of the lawn, if it is done at the right time of year, and if it is followed by another practice.

The right time of year is generally fall, although early spring is okay, too. The other practice is discussed next and it is lawn top dressing.


  1. GreenerGreenGrass says:

    You are so right about core aeration. Have you ever thought about using a liquid aerator? It works on a microscopic level by using opposing charges to push soil colloids apart, creating space in the soil for air, water, and nutrients. It’s great for both lawns and gardens.

    1. It seems to me to be a band-aid solution rather than focusing on balancing the soil nutrients and increasing organic matter content and microbial diversity and numbers. Core aeration is also a band-aid solution when done alone, but when done as a means to reach these other ends, it is useful. Interesting idea, but I would rather add these things to my soil than ammonium laureth sulfate.

  2. As a business owner I find that most of the calls we receive are from homeowners whose lawns are in decline. Aeration has been a great tool to help us renovate lawns.

  3. I have been doing aerating for over 4 years now. However i have a problem that I think has been caused by the aerating. I have hundreds of “mounds or hills” that look like giant ant hills which have made the entire lawn very bumpy. I noticed last Fall that hundreds of mounds, that looked like big ant hills were rising on the lawn.Each mound looked hardened like as if crystalized water….Now the lawn is so bumpy its hard to walk on and even harder to mow because its so un even. I found one way to rid these mounds is to manually walk the lawn and break up each mound by hand or raking back and forth…Has anyone else had this problem…??

    1. It seems there is something about your lawn that the ants find attractive, so fixing that issue will gradually decrease the ants. It could be that the lawn is too dry, lacking humus, imbalanced in nutrients, lacking a healthy soil food web, etc. It takes some knowledge to figure that all out, but it can be done. I’m not sure if your aeration will be contributing to it…

  4. Candace Ramlall says:

    Hi I have a question, if I wanted to aerate a sunflower plant for a project how would I go about doing this?? And would the deeper the aerated holes be more beneficial for the plant? Thanks

    1. Hmm, I’m not sure exactly what you’re asking here.

  5. I can’t believe nobody mentioned Overseeding. aerating without doing the other half of the equation is pointless

    1. Especially with bunch type grasses that don’t spread laterally

      1. Definitely, if your lawn is sparse, you should overseed, but only if you also address why your lawn is sparse in the first place. Hopefully people aren’t using only bunch type grasses in the lawn.And the point of aerating is not really to prepare the lawn for overseeding. It’s to get beneficial materials down into the soil, like organic matter, minerals, and microbes. Certainly if overseeding is necessary, it should be done at this time, too.

  6. How does regular aeration hurt the microbial population? I thought it would be good for microbes. From what I’ve read before, as the cores lay on the ground and decompose, it encourages microbial life and it also helps decrease thatch due to the increase in microbes.I’ve been core aerating my uncle’s lawn 2 times per year since I bought my own tow plugger last year (so I’ve actually only been doing it for 2 years). Reason is: 1. He has extremely heavy red clay soil (red shale actually) which is very compact. 2. His lawn is Zoysia grass which thatches up really quick.So I figured it would be good for his soil. Also, I only mulch his grass, including all the leaves in the fall. And it’s looking pretty good so far. It doesn’t seem like I’m hurting it (so far).

    1. Ya, 2 times per year during active root growth can be okay, especially if you add beneficial things into the holes such as fertilizers and inoculants. It may encourage some microbial life, while harming other microbial life. But the aeration itself is largely just a band-aid solution really – it doesn’t decrease compaction for very long. Compaction is a chemical and biological issue, not so much a physical issue.

      1. Thanks for the advice. Great site by the way, just signed up my e-mail.What kind of inoculants would you recommend? I’ve heard raw milk, molasses, and other weird things like that are good for microbial life.

        1. Milk can bring some benefits, but is also antimicrobial (it’s used as a natural pesticide). Molasses can be very beneficial. But those aren’t actually inoculants. My favorite inoculants are mycorrhizal fungi and ‘effective microorganisms’.

          1. Oh I see, I wasn’t quite sure what inoculants were. I’m going to have to read your website more. Thanks for the tips.

  7. When aerating a yard, what is the desired, optimum speed of the core aerator?

    1. I’ve never seen any research on that. I’m not sure how much it matters as long as the machine is performing well.

    2. When I’m aerating, I usually try to run the tractor as fast as possible because it seems to eject the cores better. Just experiment as you’re doing it. The objective is to get good 3″ cores, the speed at which you do it doesn’t matter so long as the cores are coming out good.

  8. Gerald Penney says:

    I had turf laid onto a gravelly piece of ground and while the grass seems to grow well, there are patches of brown and it’s very fine. I cut it “long” to avoid damage. If the ground underneath the grass is too compacted, would aeration help?

    1. Core aeration on its own doesn’t help much with compaction in the long run, but if you can backfill the holes with good compost, perhaps mycorrhizal fungi and perhaps appropriate fertilizers like calcium carbonate or rock dust, that could be very helpful.

  9. Philip Sherwin says:

    I am creating a lawn after building a retaining wall, backfilling with fill dirt and topping with topsoil. First I seeded it with ryegrass, but now I’m ready to overseer with tall fesque. Should I core aerate before overseeding? It’s June here in North Eastern OK. What do you think?

    1. I wouldn’t, especially this time of year. The only reason I would is if there was something I really wanted to get down into the root zone, like a mycorrhizal inoculant or a fertilizer of some kind, but that would be more appropriate in the fall or earlier in the spring.

  10. My yard is brown and looks horrible. What I am going to do in the spring is this: Thatch the yard, give it a week or 2 then use the core aerator to pull the plugs out. Once the plugs are out i will then rake the plugs and put them in my compost pile. The yard now will get a good dose of fertilizer that is high in nitrogen with a crab grass inhibitor and then I will seed, then throw a good top soil (very thin layer) on top of that and lightly rake that in. That should give me a great start to a nice lawn. What I have been researching is “lawn tea” Harvard University uses it, it is an all natural fertilizer.

  11. Mike Alcorn says:

    I live in central Florida. We have sand for soil and zoysia grass. Is aeration beneficial or not. Of course the grass is rather brown after winter and now it is March we need to make a decision on aeration, fertilization (preferably organic), etc. What are your recommendations. Thank you.

  12. I have a manual hand core Aerator however the soil under the sod we layed is sand. When I use the aerator it creates the holes however the cores donot come out. All the soil gets compacted in the aerator tubes. Is this common I. A sandy soil? I have tried a few different core Aerators and still can’t get the cores to pop out. Am I just compacting the soil when the cores don’t come out? Like I said the aerator is making 1/2” by 3” holes it just don’t pull the core. Please help me out….

    1. Ya, it’s probably not doing much good. If you topdress with an inch of good compost this year and try again next year, perhaps you’ll have better luck, as the compost will have partially worked down in with the sand.

  13. What should you do about the little plugs that are removed? Rake them up and get rid of them before applying the top dressing?

    1. Leave them there. The grass and roots will break down and provide nutrients. It looks weird at worst but goes away fairly quickly.

  14. Todd Foley says:

    What if your lawn is clay based ive heard that dethatching , airating ferltising seeding then topcover of soil whould be the way to go

  15. I live in Florida and have St Augustine grass. I have a lawn service that sprays every 6 weeks . It’s supposed to be organic. My lawn looks fine but now he keeps recommending aeration. I’ve said no before and I’m saying no now. If my lawn looks fine why do I need this? The $$$ to treat it and $$$ to treat for ants and now aeration, I just can’t.

    1. You’re probably right, especially this time of year.

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