Why, When, and How to Aerate Your Lawn

How to Aerate Your Lawn

Sometimes, we all need to take a breather, and your lawn is no exception. Aeration gives your grass the oxygen, water, and nutrient boost it needs while also improving soil drainage. But before you start this project, you should know why, when, and how to aerate your lawn.

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. Let’s dive into what aeration means, why it’s necessary, and how to begin aerating for a healthier lawn.

Why, when, and how to aerate your lawn

Aeration involves puncturing small openings in your lawn to relieve soil compaction and enhance the delivery of vital elements like oxygen, water, and nutrients to the root system. This process encourages roots to dig deeper beyond the topsoil, fostering their strength and resilience as they grow.

illustration showing how aeration works and the benefits of aerating soil
Infographic by Juan Rodriguez

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

  • 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.

Why aerate your 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.

Aerating your lawn is like giving it a breath of fresh air. Unless you have sandy soil and drainage is not a problem, it’s a good idea to consider aerating. Here are some of the reasons it’s essential:

  • Healthy roots: Grass roots need to breathe, and aeration provides them with oxygen, water, and nutrients. This helps roots grow strong and deep, making your grass more resilient.
  • Thicker grass: Aeration creates space in the soil for new grass shoots to grow. This makes your lawn denser, greener, and better at crowding out weeds.
  • Less compaction: Over time, soil can get squished down, especially in high-traffic areas. When you loosen up the soil, the roots can easily grow, and water also can soak in easily.
  • Better absorption: After aeration, water soaks into the ground more efficiently. This reduces runoff and helps your grass get the moisture it needs.
  • Weed control: A well-aerated lawn can naturally fend off weeds. Thick grass makes it harder for weeds to take root.

In a nutshell, aeration is like a spa day for your lawn, making it healthier, greener, and more beautiful.

Signs your lawn needs aeration

Is your grass not growing as densely or as green as it used to? If so, then soil compaction and nutrient deficiency may be the problem. You may need to aerate, especially if your soil is showing one or more of these compaction symptoms:

  • 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 like brown patch.

Additionally, your lawn may be a likely candidate for compaction if it experienced heavy foot traffic or it 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, making them shallow and weak. Aeration breaks up the soil layering to spur root growth.

Pro tip: A quick test to check if your lawn needs aeration is to cut out a section of your lawn around a square foot and at least 6 inches deep. If the grassroots are growing only 1 to 2 inches deep, your soil may be compacted, and aeration could give your roots a boost.

When to aerate your lawn

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

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

Do not aerate in the peak of summer heat if you want to avoid lawn stress, as the high temperatures and potential lack of moisture can make recovery more challenging. For specific aeration advice based on your region and soil type, it’s a good idea to contact your local extension office.

To tailor your aeration schedule precisely to your grass type, consult this quick guide:

Type of grassWhen to aerate
BermudagrassLate spring to early summer (Avoid when the grass is dormant in winter)
Kentucky bluegrassEarly fall
Perennial ryegrassEarly fall
St. AugustinegrassLate spring to early summer (Avoid during its dormant period in the fall)
Tall fescueEarly fall aeration allows for root growth before winter
ZoysiagrassDuring its growing season – late spring to early summer

For the best results, consider aerating your lawn:

When the soil is moist: It’s best to aerate when the soil is moderately damp but not overly saturated. To gauge this, try inserting a screwdriver into the ground. If it slips in with ease, it’s usually a good time for aeration.

Before overseeding: If you’ll be overseeding your lawn, aerate just before scattering the new grass seeds. Aeration creates tiny pockets for the seeds to settle, facilitating their growth.

Every one to three years: Generally, most lawns benefit from aeration if done every one to three years. For lawns that endure considerable wear and tear, like those frequented by children and pets, consider more frequent aeration sessions.

Remember, the right timing can make a big difference in the success of your lawn aeration. So, choose the right season for your grass type, check the soil type and moisture, and plan your aeration accordingly for a healthier, happier lawn.

How to aerate your lawn

lawn aerator on a lush green grass
Photo Credit: macniak | Canva Pro | License

Every homeowner who wants a vibrant, healthy lawn must understand the steps involved in aeration.

Step 1: Prepare the tools and materials

Before starting your project, you need to have the right aeration tools and materials, including:

  • Lawn aerator
  • Lawnmower
  • Garden hose and sprinkler
  • Markers

When choosing the right type of aerator, it will significantly depend on your lawn’s size. Here are the most commonly used:

  • Aerator shoes: For those tending to smaller lawns on a budget, aerator shoes offer a cost-effective option. Resembling sandals with spikes on the soles, they are strapped to your feet, allowing you to aerate as you walk across your lawn.
  • Core or plug aerators: Also referred to as hollow tines, this type of aerator excels at alleviating soil compaction and facilitating the passage of nutrients and air to the roots. Available in both manual and mechanical versions, core aerators are highly favored for larger lawns.
  • Liquid or soil conditioners: Liquid aerators are not machines but rather liquid products applied to the lawn’s surface. Ideal for addressing mild compaction and promoting long-term soil health, they function by breaking down compacted soil particles and gradually improving soil structure.
  • Rolling aerators: Designed to be towed behind riding mowers or lawn tractors, rolling aerators feature a roller equipped with spikes or blades that puncture the soil. They are efficient for covering extensive areas rapidly and often include adjustable settings to accommodate various soil conditions.
  • Slicing aerators: This lawn aerator has rotating blades or disks that create slits or grooves in the soil without removing cores. While less intrusive than plug aerators and suitable for addressing lighter compaction, they may not be as effective at enhancing soil aeration and structure.
  • Spike aerators: Using sharp tines, spike aerators poke holes into the soil. They offer a straightforward approach and are well-suited for smaller lawns. However, they may not be the optimal choice for clay soils, as they can compact the soil around the holes.
  • Tine rake aerators: These hand-operated tools with multiple metal tines are manually pushed or pulled across the lawn. They create shallow channels in the soil, enhancing aeration and allowing nutrients to penetrate the root zone. These tools are suitable for smaller lawns and targeted treatment areas.

Step 2: Prepare your lawn

After preparing the tools and materials, you must ensure your lawn is ready as well.

Mow the lawn

Begin by giving your lawn a neat trim using your lawnmower. Remember to cut it to the recommended height for your specific grass variety. Mowing beforehand is essential as taller grass can obstruct the aeration process, diminishing its effectiveness in combating soil compaction and limiting the advantages for your lawn.

Water the lawn

Prepare your lawn for aeration by generously watering it a day or two in advance, rendering the soil softer and more amenable to aeration. Alternatively, you can schedule aeration for the day following a rain shower.

Mark sprinkler heads and shallow utility lines

You also must take precautions by clearly marking the locations of sprinkler heads and shallow utility lines. Often situated just beneath the soil surface, sprinkler heads are susceptible to getting damaged by the aerator’s tines or spikes. It can lead to significant damage, causing disruptions to your irrigation system and incurring substantial repair costs.

Shallow utility lines like cable, electrical, or irrigation conduits are at risk of being inadvertently struck if their positions are not identified and clearly marked before aeration. Accidental contact with these lines can result in safety hazards, service interruptions, and the need for expensive repairs.

Step 3: Aerate the lawn

With all the preparations complete, you can now start the aeration process. Guide the aerator across your lawn using a crisscross pattern, ensuring each pass slightly overlaps to have good coverage. As the aerator progresses, it will pull out small plugs of soil or create small holes.

Remember to do two rounds of aeration, with the second pass crossing the path of the initial one at a perpendicular angle. This creates a pattern resembling a checkerboard or crosshatch. In areas subjected to frequent foot traffic and prone to soil compaction, make additional passes to ensure thorough treatment.

Step 4: Leave soil plugs on your lawn

Allow a few days for the extracted soil plugs to dry. Once they have dried, use the backside of a rake to break them up into smaller pieces before evenly dispersing them across your lawn.

Over time, the disintegrated plugs will naturally decompose, infusing the soil with valuable organic matter. This enriches the soil with essential nutrients while enhancing its overall structure. This organic material serves as an inherent top dressing, effectively reducing thatch buildup and fostering the growth of healthier grassroots.

Furthermore, the soil plugs can provide insulation, helping regulate soil temperature and moisture levels. They help shield grassroots from extreme temperature fluctuations and excessive moisture loss, contributing to overall lawn health.

Step 5: Apply post-aeration care

Provide your lawn with additional light watering to aid in the soil’s recovery and provide a revitalizing boost to your grass. Following aeration, continue your usual lawn care routines, including regular watering, mowing, and fertilizing.

For the next two to three weeks, aim to water your lawn every two to three days. This regular watering routine will play a crucial role in facilitating the recovery and regrowth of your lawn.

Step 6: Overseed your lawn

Enhance the density and vibrancy of your lawn by overseeding. You have two options:

  • Overseed immediately after core aeration and apply fertilizer and compost.
  • For a more uniform lawn, wait for about a month after aeration before overseeding.

The infusion of fresh grass seeds, in conjunction with compost, will promote robust growth.

Pro tip: If your lawn doesn’t require overseeding, consider applying a pre-emergent herbicide to prevent weeds from taking root in the aerated holes.

Benefits of aerating your lawn

Like a breath of fresh air for your lawn, aeration has many benefits that are both impressive and valuable:

Denser grass: By opening up pockets within the soil, aeration provides room for new grass shoots to flourish, resulting in a richer, more picturesque lawn. It also aids existing grass in filling in patchy areas.

Enhanced airflow: Just as we rely on air to breathe, so do your grassroots. Aeration creates mini ventilation channels across your lawn, like windows that usher air into homes. These pathways allow life-giving oxygen to reach the root zone.

Enhanced water absorption: After aeration, rainfall or lawn irrigation is more efficiently absorbed by the soil. This translates to reduced runoff and a higher volume of water reaching the grassroots, contributing to their well-being.

Healthy roots: Aeration supports grassroots in their quest for vitality by granting them access to oxygen, water, and nutrients. Strong and deep roots equate to healthier grass, fortified against drought and disease.

Nutrient accessibility: Your lawn, much like your body, requires nourishment. Aeration acts as a conduit, allowing crucial nutrients, such as top dressing, fertilizer, and water, to penetrate the soil’s depths, where eager roots await their feast.

Optimized fertilizer effectiveness: Fertilizers work most effectively when they can efficiently access the root zone. Aeration helps guarantee your grass reaps the maximum benefit from your lawn treatments.

Reduced compaction: Your lawn can get compacted over time, especially if it’s prone to heavy foot traffic or has heavy clay soil. Aeration performs the vital task of loosening the earth, providing roots ample space to stretch and flourish.

Weed resistance: A thicker lawn, promoted by aeration, acts as a natural adversary to weeds. The increased density makes it challenging for these unwanted invaders to establish themselves.

Additionally, aeration reduces the need to dethatch (raking up the layer of organic matter and dead grass between the soil surface and grass blades). Compacted soils with poor drainage accumulate thatch faster than well-drained soils. Aeration promotes better drainage, breaks up compaction, and stimulates microbial activity that helps decompose the thatch layer.

illustration explaining thatch on grass
Infographic by Juan Rodriguez

Cost of lawn aeration

Lawn aeration costs can vary based on several considerations. Here’s what you should be aware of:

  • DIY vs. professional: If you opt for the DIY route, your primary expenses will revolve around renting or purchasing an aerator, which can cost between $100 and $300 or more, depending on its type and size. On the other hand, hiring a professional lawn service provider typically entails costs ranging from $75 to $225.
  • Frequency: The frequency at which you decide to aerate your lawn also can impact the overall cost. A one-time lawn aeration is generally more cost-effective than regularly scheduled aeration sessions.
  • Additional services: If you opt to bundle lawn aeration with supplementary services like overseeding or fertilization, be prepared for additional expenses associated with those services.
  • Maintenance: Should you choose to purchase your own aerator, factor in maintenance expenses like potential repairs and blade sharpening.
  • DIY supplies: Going the DIY path, you should consider budgeting for necessities like fuel for your lawnmower and supplies like marking flags.

While there are associated costs with lawn aeration, view it as an investment in the vitality and aesthetics of your lawn. An aerated lawn tends to thrive, reducing the need for maintenance and treatments over time. So, weigh these expenses against the long-term benefits, considering your specific lawn care requirements and financial constraints.

FAQ about why, when, and how to aerate your lawn

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.

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. However, 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 watering 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.

How often should I aerate my lawn?

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.

Should I dethatch or aerate first?

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

What happens if 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.

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 your lawn. They’ll make aeration a real breeze.

Main Photo Credit: Alan Kidd | Shutterstock | License

Melanie Joseph

After discovering her passion for writing through her beauty blog, Melanie left her engineering job in California, became a writer, and never once looked back. When she isn't writing, she loves dipping in the pool, tending to the garden, or doing simple home improvement projects.