Aerating Your Lawn: Why, When, and How to Start

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close-up of an aerating machine on a lawn

Sometimes we all need to take a breather, and grass is no exception. Aeration gives your grass the oxygen, water, and nutrient boost that it needs, while also improving soil drainage. 

It may sound like you’re looping figure eights in the sky, but aeration is actually an easy DIY project that’ll have your grass flying high. We’ll dive into what aeration means, why it’s necessary, and how to begin aerating for a healthier lawn.

What is aeration? 

Aeration is the method of creating holes in a lawn to alleviate soil compaction and increase the flow of oxygen, water, and nutrients to roots. Aerated grass roots can dig deep into the soil, growing strong and resilient. 

illustration showing how aeration works and the benefits of aerating soil

Consistent aeration keeps your lawn healthy and green, saving you from dry grass, unsightly brown patches, and lawn problems down the road. 

Though other aeration methods exist (such as spike, blade, and liquid aeration), core aeration is considered the most legitimate and popular method of aeration among homeowners and lawn care professionals. 

Core aeration 

Core aeration, also known as plug aeration, is what most homeowners think of when they hear the term “lawn aeration.” 

  • Core aeration entails poking hollow tines into the ground using a manual aerator or an aeration machine to remove small plugs of soil.
  • The soil plugs are long and narrow, about 2 to 4 inches deep and 0.5 to 0.75 inches in diameter.
  • Plugs are removed 2 to 3 inches apart from each other.

Core aeration gives your lawn space to breathe. In the holes where soil used to be, water, oxygen, and nutrients can make their way to deprived roots. 

Why should I aerate my lawn? 

Over time, foot traffic, outdoor projects, and weather can compact your soil. Compacted soil leaves roots without room to grow and without air pockets to receive water, oxygen, and nutrients from the surface. 

Likewise, thatch (the layer of organic matter that lies between the grass and the soil surface) can build up, acting as a barrier between roots and the nutrients they need.

Aeration loosens soil, improves drainage, prevents thatch buildup, and helps roots get the food they need to grow long and strong. Unless your soil is sandy and drainage is not a problem, it’s a good idea to consider aerating.

Signs your lawn needs aeration

If your grass isn’t growing as densely or as green as it used to, soil compaction and nutrient deficiency may be the problem. 

If your soil is showing one or more of these compaction symptoms, you may need to aerate: 

  • Your soil is hard to the touch.
  • Your lawn feels spongy and dries out easily.
  • During rainstorms, water forms puddles instead of being absorbed by the soil.
  • Your grass is thinning, withering, or losing its green color.
  • Your grass is developing diseases such as brown patch

Your lawn also may be a likely candidate for compaction if:

  • Your lawn gets heavy foot traffic.
  • Kids and pets frequently play in your yard.
  • Your house was newly built. Construction work leads to compacted soil.
  • Your lawn was laid from sod. If sod was laid over compacted soil and the soils were not mixed, roots won’t grow into the ground beneath the sod. This makes them shallow and weak. Aeration breaks up the soil layering to spur root growth.

A quick test to check if your lawn needs aeration? Cut out a square foot section of lawn at least 6 inches deep. If grass roots are growing only 1 to 2 inches deep, your soil may be compacted and aeration could give your roots a boost.

Aeration: A two-for-one deal

Aeration offers you two lawn deals for the price of one. Not only does it improve grass strength and stimulate growth, but it also reduces the need to dethatch your lawn (raking up the layer of dead grass and organic matter that lies between the grass blades and soil surface). 

illustration explaining thatch on grass

Regularly aerating your lawn will cut down on the hassle of renting out and using a dethatcher or power rake.

Why does aeration decrease your need to dethatch?

  • Compacted soils with poor drainage accumulate thatch faster than well-drained soils.
  • Aeration promotes better drainage and breaks up compaction.
  • Aeration stimulates microbial activity that helps decompose the thatch layer.

Aeration also reduces harmful stormwater runoff and increases your grass’s drought tolerance. With core aeration, your lawn won’t be just a pretty face. It’ll also be an eco-friendly water-saver

When should I aerate? 

You’ll want to aerate during your region’s growing season so that grass recovers quickly and fills the holes in your lawn.

  • For cool-season lawns with grasses like tall fescue and Kentucky bluegrass, fall is the ideal time to aerate. While you can aerate cool-season lawns in either early spring or early fall, fall is preferred because weeds are less likely to sprout in the holes created by aeration.
  • For warm-season lawns with grasses like Bermudagrass and Zoysia, aerate in late spring or early summer for quick grass recovery. 

To avoid lawn stress, do not aerate in the peak of summer heat.

For specific aeration advice based on your region and soil type, it’s a good idea to contact your local extension office

How do I aerate my lawn? 

person manually aerating a grass area using a pitch fork
Eugene Brennan | Pixabay

Aerating sounds intimidating, but it’s actually a simple afternoon project, especially if your lawn is on the smaller side. 

For small spaces, a handheld, pronged lawn aerator will do the job. For larger spaces, you can opt for a wheeled walk-behind aerator or even rent a tow-behind aerator. 

Wheeled aerators are the machines of choice for most homeowners. You can rent one from a home improvement store or garden center. 

With your aerator in hand, a healthy lawn is just seven simple steps away. 

Steps to aerate your lawn

  1. Water your lawn 1 inch deep a day before aerating. This will soften the soil. Alternatively, aerate the day after a rainstorm. 

Pro tip: To promote grass recovery, you may want to fertilize your lawn a week prior to aeration.

  1. Mark sprinkler heads and shallow utility lines to ensure you don’t hit them when aerating. Dusting flour over spots to avoid can help you see exactly where not to aerate.
  1. “Mow” your lawn with the aerator. Go over your lawn twice. The second aeration should be perpendicular to the first aeration, creating a checkerboard pattern. You may want to target compaction-prone areas with heavy foot traffic for a third or fourth pass. 
  1. Leave soil plugs on your lawn. Let them dry for a few days, and then break them up with the back of a rake and rake them into your lawn. They’ll decompose thatch and act as a natural top dressing, returning nutrients to the soil.
  1. Apply fertilizer, compost, and manure. This is the golden hour for lawn amendments. If you haven’t already fertilized, now is the time to set your new grass up for success. Spread compost over your lawn and rake it into the holes to give your lawn a nutrient boost. 

Pro tip: If you aren’t planning to overseed your lawn, apply a pre-emergent herbicide to prevent weeds from growing in the holes.

  1. Overseed for a denser, greener lawn. You can overseed directly after coring alongside the fertilizer and compost, or you can overseed a month after coring for a more even lawn. New grass seeds will flourish in combination with the compost.
  1. Water every two to three days for the next two to three weeks to help your lawn heal and regrow. 

FAQs

1. What’s the difference between dethatching and aeration? 

Aeration alleviates soil compaction, while dethatching eliminates thatch (the layer of dead grass and organic matter that settles just above the soil line). 

Soil compaction and excessive thatch both cause serious problems for your lawn’s growth because they keep oxygen, water, and nutrients from reaching the lower soil. However, they have to be addressed differently. While aeration pokes holes in the soil, dethatching rakes up the thatch layer.

2. Does my lawn need to be dethatched, aerated, or both?

Regular lawn wear and tear over the year will compact your soil, so it’s a good idea to aerate annually (though your specific aeration schedule will depend on your soil type and level of compaction).

Your dethatching needs are based on your grass type and soil conditions. Bermudagrass, bentgrass, and Kentucky bluegrass can produce thick thatch, whereas fescues and perennial ryegrass may never need to be dethatched. 

Overwatered and overfertilized lawns produce thatch quickly, so cutting back on frequent waterings and fertilization can decrease thatch buildup. 

To determine the thickness of your thatch: 
Use a shovel to remove a small, 3-inch-deep sample of your lawn. 
Measure the brown layer between the grass blades and the soil surface. 
If the brown layer is over half an inch long, your lawn could use dethatching. 

A light layer of thatch is healthy for your lawn, but thatch that is more than half an inch thick will impede grass growth. Verticutting is a heavy-duty alternative to using a power rake.

3. Should I dethatch or aerate first? 

If both thatch and soil compaction are a problem, you’ll want to dethatch before you aerate. 

4. How often should I aerate my lawn? 

It depends on your soil type, but for most homeowners, aerating annually is a good rule of thumb.

How often to aerate for different soil types:
If you have sandy soil with few drainage issues, you’ll only need to aerate every two or three years. 
If you have heavy clay soil or if your lawn experiences frequent foot traffic, it’s a good idea to aerate every year or even twice a year. 

5. Can I apply herbicide after aerating? 

A pre-emergent herbicide can stop weeds such as pesky crabgrass from growing in the holes you’ve created. 

However, synthetic herbicides can harm new seeds and prevent healthy growth. If you’re planning to overseed after aeration, hold off on a broad herbicide application. Instead, spot spray if weeds emerge.

6. How much does a core aerator rental cost? 

Renting a gas-powered, walk-behind core aerator costs approximately $65 for four hours or $100 for a full day. 

Aerate for a healthy lawn

With aeration, your grass will grow densely for a lush, healthy landscape that makes your neighbors green with envy. Plus, you’ll have peace of mind knowing all’s well beneath the soil surface. 

If you’d like the experts to get your soil in peak condition, you can hire a local lawn professional to aerate for you. They’ll make aeration a real breeze. 

Main Photo Credit: Shutterstock

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