Not all lawns need aeration- find out if and when yours needs it
Summary points:
- Only aerate if your soil is compacted—don’t do it “just because.”
- Signs of compaction: sparse grass, hard soil, poor water drainage.
- Sandy soils never need aeration.
- Only use core aeration, never spike tools, to loosen your soil.
- Spring or fall are the best times—never aerate in summer.
- Organic lawns rarely need aeration due to healthy soil biology.
If you’ve had a lawn for any length of time, you may have come across the idea that you should aerate every year. But is that really true? The short answer: No. You only need to aerate if your soil is compacted.
Compacted soil happens when soil particles get pressed tightly together, making it hard for air, water and roots to move freely. This happens often with clay soils, and soils that lack organic matter. Common signs include grass that’s patchy or weak, puddles that linger after a rain, or soil that feels like hardened clay when you press on it. If your grass is growing nicely, drains well and feels soft underfoot, there’s no need to aerate.
Sandy soils basically never become compacted, so if that’s what you’re working with, aeration should be a non-issue. (What you're going to want to do with sandy lawn soil is add organic matter to help "bulk up" the soil so it can hold nutrients and water. Top dress with composted materials and fertilize with organic fertilizer.)
But if your lawn does need aeration, make sure you’re doing it right. That means core aeration—those machines that pull out plugs of soil, either through a local lawn company or a machine rental from a place like Home Depot or Lowe’s. Do not use spike shoes or those spiked rollers you see behind riding mowers; they actually compact your soil more, rather than loosening it.
Aeration should only happen in the spring or fall—these are the seasons when cool-weather grasses (like we have in Michigan) are at their strongest. Doing it in summer, when turf is already stressed by heat and drought, can cause more harm than good.
If you do go through with core aeration, it’s also the perfect time to overseed. Those open holes create space for seeds to germinate—and unfortunately, weed seeds love that space too. Beat them to it by putting grass seed down right away. You can also take advantage of the open soil by top dressing with compost or applying an organic fertilizer to boost your soil's organic matter while it’s most receptive. A top-dressing of pelletized gypsum at this time can also help to further loosen up your soil and keep it loose.
And here’s something that may surprise you: If you’ve got a healthy organic lawn, you probably won’t need to aerate at all. Why do some modern lawns even need aeration then? Synthetic chemical fertilizers. Chemical lawn care strips soil of organic matter and kills off natural aerators—like worms, bacteria, beetles, and fungi. Over time, that causes your soil to become lifeless and compacted. But an organic lawn, rich in life and organic matter, naturally stays loose and healthy.
So before you decide to go the core aeration route, take a good look at your lawn’s health. If it’s doing well, skip the aerator this year. If the soil's soft or sandy, skip it as well. You really only need to do it as a last resort when things get really compacted beneath your turf.
Compacted soil happens when soil particles get pressed tightly together, making it hard for air, water and roots to move freely. This happens often with clay soils, and soils that lack organic matter. Common signs include grass that’s patchy or weak, puddles that linger after a rain, or soil that feels like hardened clay when you press on it. If your grass is growing nicely, drains well and feels soft underfoot, there’s no need to aerate.
Sandy soils basically never become compacted, so if that’s what you’re working with, aeration should be a non-issue. (What you're going to want to do with sandy lawn soil is add organic matter to help "bulk up" the soil so it can hold nutrients and water. Top dress with composted materials and fertilize with organic fertilizer.)
But if your lawn does need aeration, make sure you’re doing it right. That means core aeration—those machines that pull out plugs of soil, either through a local lawn company or a machine rental from a place like Home Depot or Lowe’s. Do not use spike shoes or those spiked rollers you see behind riding mowers; they actually compact your soil more, rather than loosening it.
Aeration should only happen in the spring or fall—these are the seasons when cool-weather grasses (like we have in Michigan) are at their strongest. Doing it in summer, when turf is already stressed by heat and drought, can cause more harm than good.
If you do go through with core aeration, it’s also the perfect time to overseed. Those open holes create space for seeds to germinate—and unfortunately, weed seeds love that space too. Beat them to it by putting grass seed down right away. You can also take advantage of the open soil by top dressing with compost or applying an organic fertilizer to boost your soil's organic matter while it’s most receptive. A top-dressing of pelletized gypsum at this time can also help to further loosen up your soil and keep it loose.
And here’s something that may surprise you: If you’ve got a healthy organic lawn, you probably won’t need to aerate at all. Why do some modern lawns even need aeration then? Synthetic chemical fertilizers. Chemical lawn care strips soil of organic matter and kills off natural aerators—like worms, bacteria, beetles, and fungi. Over time, that causes your soil to become lifeless and compacted. But an organic lawn, rich in life and organic matter, naturally stays loose and healthy.
So before you decide to go the core aeration route, take a good look at your lawn’s health. If it’s doing well, skip the aerator this year. If the soil's soft or sandy, skip it as well. You really only need to do it as a last resort when things get really compacted beneath your turf.