If your lawn feels spongy underfoot or struggles despite regular watering and fertilization, the culprit may be thatch.

In this edition of Healthy Lawns with Dr. Jim, Dr. Jim Wilkinson, founder and owner of SeaScape Lawn Care, explains how thatch develops, when it becomes a problem, and why core aeration is often the best long-term solution for maintaining a healthy lawn.

What Is Thatch?

Thatch is a layer of dead and living organic material that accumulates between the green grass blades and the soil surface. A thin layer is perfectly normal—even beneficial—but when that layer grows to about an inch or more, it can begin causing problems.

Excessive thatch can:

• Prevent water from reaching the soil
• Reduce nutrient absorption
• Limit oxygen exchange
• Create an ideal environment for insects and lawn diseases
• Make your lawn more susceptible to drought stress

Dethatching: A Fast Fix with Drawbacks

When thatch becomes severe, dethatching may be necessary.

A dethatching machine, sometimes called a power rake, uses vertical blades to pull the thatch to the surface where it can be removed.

While effective, there’s a downside.

Because the machine aggressively tears through the turf, it doesn’t just remove thatch—it also pulls out healthy grass. Afterward, homeowners are left with a large amount of debris that must be raked up and disposed of, and the lawn often requires time to recover.

Why Core Aeration Is the Better Long-Term Strategy

Rather than aggressively removing thatch, Dr. Wilkinson recommends regular core aeration as the preferred approach for most lawns.

During core aeration, a machine removes thousands of small plugs of soil from the lawn. Those plugs are left on the surface, where they gradually break apart.

As the soil filters back into the thatch layer, naturally occurring microorganisms help decompose the organic material over time.

The result is a healthier lawn with:

• Improved airflow to the roots
• Better water infiltration
• Increased nutrient movement into the soil
• Reduced soil compaction
• Natural control of thatch buildup

How Often Should You Aerate?

Core aeration isn’t an overnight fix for a lawn with severe thatch, but it’s one of the best preventative maintenance practices available.

For most cool-season lawns, aerating every year or every other year helps keep thatch from becoming a serious problem while improving overall turf health.

The Bottom Line

If your lawn already has a thick layer of thatch, dethatching may occasionally be necessary. But for most homeowners, routine core aeration is the smarter, healthier, and more sustainable way to manage thatch before it becomes a problem.

Regular aeration not only helps control thatch naturally, but also creates healthier soil conditions that allow your lawn to thrive season after season.

If you’re unsure whether your lawn needs dethatching or aeration, the lawn care professionals at SeaScape can evaluate your turf and recommend the best solution.