Lawn Dethatching Vs Lawn Aeration

By Allyn Paul, filed under Lawn Tips.

Spring is dropping off quickly and summer will soon be rushing in, but it is never too late to aerate! You guys know I am a huge advocate of lawn aeration, but what if you think you need to dethatch?

De-thatching the lawn means you use a machine, appropriately called a “dethatcher” that literally combs through the lawn just above the soil line with a spiked roller. These spikes rip and pull the thatch from the lawn. I rarely recommend dethaching unless it is an extreme case.

Recently in my lawn care travels (yep, I see many lawns each week here in the Midwest) I have stepped on several that desperately needed dethatching.

Thatch is the layer of mostly dead grass roots and other organic matter that reside just above the soil line. If the layer of thatch is less than a half inch thick, we’re good, but when it gets thicker, and the lawn feels “spongy” underfoot, then something must be done.

If the thatch layer is around 3/4 inch or less, you can have the lawn aerated in the spring and fall and keep it within an acceptable range. If you are at the top end of this scale, go over the lawn twice with the machine.

However, if you are over that 3/4 inch limit, you need to rent the dethacher and get to work. The good news is that most dethatching machines can be adjusted, height-wise. My advice is to test it out on a small spot first. You don’t want to scrape it down to the bare dirt. In fact, leave that 1/2 or even 1/4 inch in there.

So keep in mind, it is fine to dethatch, but only in extreme cases. If your lawn just won’t green up, even when you fertilize, check the thatch layer and see if this is the problem.


Wondering "what to" put on your lawn and "when to" put it down? Get my $7 Step By Step ebook and learn it! I am really proud of the results my readers are getting using this easy to follow lawn treatment schedule.

Lawn Care Step By Step Buy Now

Lawn Care Step

You can start at ANY time during the year... I wrote the book so it is easy to get into lawn care no matter what time it is... Just start NOW! Lawn Care, Step By Step

2 Responses to “Lawn Dethatching Vs Lawn Aeration”

  1. Lance Says:
    4Avatars v0.3.1 v0.3.1

    We just had the dethatching and aeration done at our new home (suburb of Chicago) by a landscaping company, although the home has been around since 1948. I then over-seeded and put down a starter fertilizer. The lawn looks pretty thin right now, about .25 acre lot. Our Neighbor said the front lawn was new in 2006 from seed do to an old tree falling down and no grass grew under the tree. That is where the thatch was the worst. Do you recommend aeration once or twice a year? Any other recommendations to get our lawn looking great. Should I have the ground levels tested at our local farm bureau? Thanks for the blog as I am a first time home owner. From the sound of it, this is going to a couple year process.

  2. Allyn Paul Says:
    4Avatars v0.3.1 v0.3.1

    Hi Lance, I am in NW Indiana, so I know what you got going on. You have clay soil, and that’s a good thing.
    You are right, however, it is a slow process, but it will come along.
    You need to fertilize regular, mow tall and water 2x per week in the summer.
    I def recommend aerating 2x per year if you can… spring and fall. overseed again in the fall at 3lbs per 1,000 sq feet of lawn space and keep the seed watered.

Leave a Reply