Aeration is often touted as important, but it's often a task that's ignored, especially by homeowners with large lawns. In fact, our own group of friends questioned me to learn if it was truly necessary. The short answer is yes—sorry, guys—and it's especially important for some types of lawns. Aeration not only helps your grass grow stronger roots, but it also prepares your lawn for better growth come spring. To validate this, I reached out to the experts at Scotts for insights on aeration and best practices for fall lawn care.

What is Aeration and Why is It Important?

Aeration is the process of creating small holes in the soil to remedy soil compaction. "Aeration creates channels for air, water, and nutrients to move deeper into the soil, promoting stronger root systems and overall healthier grass," highlights Matthew Koch, Ph.D., Director of Biotechnology, Genetics, and Seed at Scotts. Over time, soil in an otherwise healthy lawn can become dense and compacted, which prevents the soil from "breathing." When the soil can't breathe, it means the nutrients have a hard time reaching the root system. Aeration solves this by improving the soil structure.

Key Benefits of Aeration:

• Improves soil structure by breaking up compacted areas
• Enhances access to nutrients and improves proper nutrient absorption, which promotes deeper root growth
• Reduces water runoff by allowing better water flow through the soil
• Breaks down thatch buildup to prevent fungal growth and improve lawn health

Why should you aerate your lawn in the fall?

"Fall aeration is ideal for cool-season grasses because it allows the grass to recover and strengthen before winter," says Koch. If you have cool-season grasses like Kentucky bluegrass, fescue, or ryegrass, fall is the best time to aerate.

For warm-season grasses such as Bermuda or Zoysia, the best time to aerate is late spring or early summer, but you can still aerate in early fall if done soon enough to allow for recovery before temperatures drop.

Regional Considerations:

• Northern US (Cool, Wet Climates): Fall is the ideal time to aerate before the first frost. Get it done before your grass is in its dormant winter period.
• Southern US (Warm, Arid Climates): Aerate in early fall or late spring for best results, especially in regions where compacted soil from dry weather conditions is common.

Spike Aeration vs. Core Aeration

There are two main methods of lawn aeration: spike aeration and plug (core) aeration. "Plug aeration is generally recommended because it removes soil cores, which opens up more space for air, water, and nutrients to reach the grass roots," explains Koch. Spike aeration, on the other hand, can sometimes make compaction worse by pressing the soil down around the holes. While both methods can help alleviate compaction, soil plug aeration is often more effective (especially in heavy clay soil) because the plugs of soil open more space in the soil surface for air and nutrients.

Which Method Should You Choose?

• Spike aeration: Easier and more accessible for small or slightly compacted lawns.
• Plug aeration: Removing cores of soil is better for heavily compacted soil and has longer-lasting benefits

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Should You Also Overseed Your Lawn in the Fall?

If you’re already aerating, yes, do the thing. Overseeding in the fall is a great trick to a healthier spring lawn, especially for landscapes that use cool-season grasses. Overseeding helps to fill in any thin or bare patches in your landscape, giving it a thicker, healthier appearance. "Aeration with overseeding also helps the grass seeds penetrate deeper into the soil, which can significantly improve germination rates," notes Koch.

Benefits of Overseeding After Aeration:

• Thickens your lawn and reduces bare spots
• Improves the grass variety by introducing new, more resilient grass types
• Enhances overall lawn health by reducing the risk of weeds

For best results, overseed immediately after aerating, followed by a deep watering. If you saw our article on how to plant grass seed in the fall, you'll know that the seed needs time to establish itself into healthy grass before winter.

Can You Make Any Mistakes While Aerating?

While aeration is a relatively straightforward process, there are a few common mistakes you’ll want to avoid to ensure your yard benefits fully.

• Not watering beforehand. Aerating dry ground is much harder (and less effective). Water your lawn a day or two before aerating to soften the grass and underlying dirt.
• Skipping fertilization. "After aeration, it’s essential to follow up with a good fertilizer like Scotts® Turf Builder® Lawn Food," suggests Koch. Access to fertilizer helps the grass roots when they need it the most—right after aeration when the fertilizer can make direct contact with the dirt.
• Aerating at the wrong time. Aerating too late in the season can prevent an otherwise healthy lawn from recovering before winter. Aim for early to mid-fall for cool-season grasses and early fall or late spring for warm-season grasses.

How to Aerate Your Lawn in 5 Steps

If you’re new to aerating, don’t worry—it’s a simple process you can do yourself with a rented aeration machine, or you can hire a professional. Depending on the size of your lawn it may be an all-day or all weekend project, but you'll be happy come spring when you walk through your healthier lawn.

1. Water your lawn one or two days before aerating to soften the soil.
2. Aerate the lawn using a plug or spike aerator, going over the entire lawn in a pattern that covers all areas.
3. Apply fertilizer immediately after aeration to feed the roots as they absorb water and nutrients more efficiently.
4. Water the lawn again to help the soil settle and allow the nutrients to penetrate deeply.
5. Overseed (optional) for thicker growth and better lawn coverage.