My lawn which is a combination of clover, moss, crabgrass, dandelions and occasionally some grass is going to be aerated in two weeks. I want to know the immediate steps to take after the cores are pulled.

I have read the two best things to do are to leave the cores and to water the lawn because this will help the roots. I have also read NOT to water because it will just re-encouraged the ground to become compacted.

Anyone have insights?

Edit: My goal is to eventually get the soil prepped and ready for growing a healthier thicker lawn.

  • Are you trying to get more grass to grow?
    – J. Musser
    Commented Sep 10, 2014 at 19:01
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    I'd collect some plugs, and get them tested. Those weeds, plus the fact that your soil is compacted, makes me think the pH is a little low, and the organic matter content could be greatly improved. I would also take this opportunity (and time of year) to overseed your lawn. This is a very broad question.
    – J. Musser
    Commented Sep 10, 2014 at 19:17
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    Usually a plugger leaves holes all through the lawn, which grass seed will germinate in. I often overseed weedy lawns for folks once I run through with the plugger.
    – J. Musser
    Commented Sep 10, 2014 at 19:50
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    If you're looking to replace the lawn in the near future, raking out a 1" layer of compost in your lawn will improve conditions while not killing what you already have. fter the grass is used to it, and moved up, you can repeat. This really improves soil texture, and promotes a very healthy lawn.
    – J. Musser
    Commented Sep 10, 2014 at 19:54
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    I've talked to people at a local store here in Columbus, OH who have taken classes at Scotts. They recommend overseeding before, not after, aerating. They claim the seed that falls into the plug holes will never germinate due to lack of light. The holes are simply too deep. Plugs breaking apart and covering the seed is better.
    – Evil Elf
    Commented Sep 11, 2014 at 13:35

4 Answers 4


Leave the cores on the grass! Water deeply only when you are able to see your footprints left on your lawn/grass. Great indicator. Use a spade to see how deep the water reached into the soil profile after 15 minutes. It should be a minimum of 4". 6" is better depending on the porosity of the soil.

Allow the lawn to dry out and don't water again until you leave footprints on your grass! Watering a few minutes once every day is promoting shallow roots and the first time you forget to water might stress your grass to the point it will go dormant. Stressed grass can not compete with highly competitive weeds!

Another common mistake is to cut your lawn too short. 2 1/2" is too short for the grasses I am familiar with, here in the Pacific Northwest. I'll go look up your profile to see what types of grass with which you might be dealing. Raise your deck up as high as you can to see if you can cut your lawn no lower than 3". The soil stays shaded preserving moisture and weed seeds don't get enough light to germinate.

If you have the same types of lawn grasses (bluegrass, fescue...) these species genetically have huge root systems. If there is not at least 3" of photosynthetic top growth the plant can't make enough food to feed the roots and you have stressed, whimpy grass allowing weeds to get started in the sparse lawn.

Here is a tip that will make a humongous difference: Fertilize at least twice a year with a slow release organic fertilizer. I used Dr. Earth Lawn Fertilizer and was blown away with the difference in my lawns! A bit more expensive but it lasts longer, adds bacteria that aid thatch-breakdown, and beneficial fungi that help the plant uptake nutrients, water.

Don't mess with moss-killer, that will lower your pH and lawns love a bit higher pH (6.5-6.8). If you want a beautiful lawn you should definitely get your soil tested. Only add lime if the pH is below 6.5 and follow the instructions! Moss is an opportunist...if you water everyday, if you have any bare spots, shade with sparse grass, moss will grow! If you get your grass healthy, mow high and allow to dry out in between watering (about 1" per week...you'll have to train your grass in steps to get deep roots to last a whole week)! I only watered my 'trained' lawns, once per week and they were thick, cool, soft and no weeds. Aerate once per year minimum. You might want to up it to a second aeration for a few years. If you have more than 1" thatch you will need to do it and then reseed, mulch, roll...etc. Lot of work but really is for drastic measures as it ruins your lawn thus having to start over.

Hope this helps, there are more things one needs to learn in order to have a beautiful and healthy lawn! Stay away from herbicides, pesticides and quick fix instant fertilizers that call themselves 'plant food.' Plants make their own food only needing us to add certain nutrients because we start with poor soil, compacted during construction, poor mowing practices.

There are a bunch of great question/answers concerning lawns on this site that will give you even more knowledge and tools that will help you achieve mastery over this 'beast', the lawn.

  • Agreed, treeNinja you should read all the questions in the lawn and lawn-repair tags.
    – Philip
    Commented Sep 12, 2014 at 23:10
  • Thanks Stormy for all extra information. I was interested in what actions to take immediately take after aeration. I will update my original question.
    – treeNinja
    Commented Sep 15, 2014 at 16:07
  • Nice to 'do nothing' huh! Once one learns how nature works at least the basic patterns, things get much easier. The more work we have to do means we aren't working within 'the pattern'...does that make sense?
    – stormy
    Commented Sep 15, 2014 at 19:28

As stated above, any lawn renovation should start with a comprehensive soil test (available here) for $30 or so. For that money they'll even tell you how much of what soil ammendments you deed to apply.

But IF you are going in blind, it seems almost a wast to aerate and stop at that. When we do lawn rejuvenations, we start with good core aeration (covering areas in two directions), leave the plugs in place, and then seed and topdress with 1/4" - 1/2" of screened, finished compost. The seed needs to be appropriate to your conditions. But again, if you are going in blind, go with a sun/shade mix of bluegrasses and fescues to hedge your bets. Then provide enough irrigation to keep the soil, compost, and seed from drying out until the grass has sprouted and a more standard irrigation regime can help it get established.


Purists I once knew would rake up all the cores and then fill the holes with sand; but that was starting with a pristine lawn. I wouldn't even bother to spend the time and money aerating a grungy lawn until you get the grass to grow. I just bought a pull behind aerator for my new lawn tractor; both of which I had owned before at a previous house. I always just let the cores melt back into the soil naturally: no special watering, seeding, or fertilizing. And to keep the need for aerating to a minimum make sure there are plenty of worms in the lawn.

  • Why would you fill the holes with sand? That's really not a great idea. It's best to keep the soil native, if something is to be added, compost will be better than sand.
    – J. Musser
    Commented Sep 15, 2014 at 23:29
  • I have never heard of adding sand, the ground is so hard I doubt grass roots will be able to get into the ground.
    – treeNinja
    Commented Sep 16, 2014 at 13:20
  • The primary function of aeration by pulling plugs of soil out of the lawn is AERATION. To get air to the decomposers to decompose the not decomposed organic matter, clippings and to get air into the soil for the roots of the grass and other critical biologicals. Sand does NOTHING. Micro organisms come up to eat decomposed organic matter not sand, they take their dinner back down into the soil profile and POOP it out mixing organic matter into the soil the good old fashioned way not needing any energy from the human. The ONLY WAY to improve ANY soil is adding decomposed organic matter.
    – stormy
    Commented Nov 30, 2016 at 21:24
  • grass is far more hardy than that TreeNinja, grass can survive on hard packed soil as well as pure gravel. This dude about the golf course sand stuff has just been put in his place by my golfer (very proficient) husband. He just said THEY LEAVE THE CORES ON THE SURFACE THEY DON'T ADD SAND. Golf course maintenance depends on who is in charge. Cutting cool season grasses down below 3" is stupid. Some golf courses hire people that know what they are doing others not so much!! They usually use Poa annua a weed grass that has shallow roots and does fine mowed short.
    – stormy
    Commented Nov 30, 2016 at 21:30
  • Those birds eat the seeds of this anemic green grass and poop them out on all of the beautiful, dark green grasses of the lawns all around the golf course. Ruining the crops of the rich people who don't know a thing about grasses and lawns. If they fill those holes with sand they need to go get educated again about perpetuating a healthy soil bed for their grasses. J. Musser is correct!! The only thing to 'fill' these holes with or top dress the crop of grass is decomposed organic matter.
    – stormy
    Commented Nov 30, 2016 at 21:36

Seed does not require light to germinate,it only needs light when it is started to sprout. So even seed which is in the hole left by your pluger,may show growth.

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