Lawn aeration is essential for maintaining a healthy, thick lawn in Minnesota. But timing is everything. Here's when and why you should aerate.
What Is Aeration?
Core aeration removes small plugs of soil from your lawn, creating channels for air, water, and nutrients to reach grass roots. It relieves soil compaction and promotes healthier grass growth.
Best Time to Aerate in Minnesota
For cool-season grasses (Kentucky bluegrass, fescue) that dominate Minnesota lawns, the best time to aerate is late August through September.
Why fall? Grass is actively growing, soil is still warm, and the lawn has time to recover before winter. Aerating in fall also gives you the perfect opportunity to overseed.
Spring Aeration: Proceed With Caution
While spring aeration is possible, it's generally less ideal because:
• Disrupted soil can bring weed seeds to the surface
• Spring is prime time for crabgrass germination
• Grass is still emerging from dormancy
If you must aerate in spring, do so early (April) and apply pre-emergent herbicide after the soil has settled.
Signs Your Lawn Needs Aeration
• Heavy clay soil (common in Minnesota)
• Lawn gets heavy foot traffic
• Thatch layer exceeds ½ inch
• Water puddles or runs off instead of soaking in
• Grass struggles despite proper watering and fertilization
How Often to Aerate
Most Minnesota lawns benefit from annual aeration. Lawns with heavy clay soil or high traffic may need aeration twice per year.
Combine With Overseeding
Fall aeration paired with overseeding is a powerful combination. The seed falls into the aeration holes, making excellent soil contact for quick germination.