Why Is Late Summer the Best Time to Aerate Your Lawn for Healthier Grass Growth?

Late summer is the best time to aerate your lawn because the soil is still warm, the grass is actively growing, and the roots can recover quickly before winter sets in. Aeration allows air, water, and nutrients to penetrate the soil more effectively, breaking up thatch and strengthening root systems. When timed properly, typically in August or September for most regions, it helps fertilizer work better, boosts drought resistance, and sets the stage for a lush, healthy lawn in spring. This article explains why timing matters, how aeration supports root health, and what tools or methods work best for do-it-yourself homeowners and professionals alike.

By late summer, it’s common for lawns to have developed thatch, a mix of dead grass, stems, leaves and other debris. This makes it more difficult for aeration to occur naturally.

For most parts of the U.S. and Canada, August and September are ideal months to aerate lawns prior to fall fertilization, before temperatures drop and soil hardens. This will maximize the benefits of the fertilizer, strengthen the root system and foster a healthier spring lawn.

Note: Ideal timing for aeration/fertilization timing may differ in your region, as it depends on the grass type. Call your local university’s horticulture or turfgrass department or speak with staff at your local garden center about when aeration is best for your grass type.

Most landscaping businesses offer lawn aeration services but it definitely can be a do-it-yourself project, too. It’s commonly called “core aeration” in the landscaping – lawn service industry. It’s also frequently referred to as lawn cultivation, lawn or soil coring, spiking and slicing.

Do-it-yourself aeration can be done using a simple garden fork to remove small plugs of thatch and soil. For more expansive lawns, you should consider renting a lawn dethatcher and/or core aeration tool from a local home improvement store or garden center. A professional tool will enable you to cover more lawn, faster.