What are aerator shoes—and do they really work?

It sounds like a great deal: Buy a pair of shoes with spikes on the bottom and make your lawn look better by just walking around! Aerator shoes aren’t too expensive—a pair will run you around $25—and using them to introduce more oxygen into your soil takes a lot less effort than pushing a mower or re-seeding and watering your lawn. But do they actually work? Let’s dig in.

First off, do you even need to aerate your lawn?

There isn’t one clear answer. Most lightly-used lawns don’t need aeration at all; they need compost, more water, or reseeding.

Your lawn may be compacted in areas that get very heavy foot traffic, or where you’ve been driving cars or construction equipment. A compacted lawn may also have places where water puddles after a rain, or where stormwater simply runs off without soaking into the soil—but that could also be the result of poor-draining soil or a swampy location, not compaction.

Experts at Clemson University suggest the “screwdriver test.” Choose a day when your soil is moist. Take a standard screwdriver and try to stick it into the ground. If you can push it in easily, your soil isn’t compacted, and your lawn probably doesn’t need aeration. If you can’t push the screwdriver into the soil, your lawn could probably benefit from aeration.

When should you aerate your lawn?

If you live in the north, aerate your cool season grass lawn in the early fall, when the grass is entering another fast-growth phase and will still have time to recover before frost. Aerate warm season grass lawns in June and July, when they’re growing fastest.

So, what are aerator shoes?

Simply put, aerator shoes are sandal soles with spikes attached. They’re supposed to make holes in your lawn to allow more water and air to reach the grasses’ roots, encouraging growth. Many grasses also send up new shoots when their roots are severed, increasing the density of your lawn.

Most aerator shoes have spikes that are about 2 inches long and an eighth of an inch thick; they look a lot like roofing nails. The straps that hold the spikes onto the bottom of your foot can be adjusted to fit over regular shoes, sneakers, or work boots.

To use aerator shoes, strap the soles onto your shoe, spikes down, and then walk around on your lawn. Your body weight drives the spikes into the lawn, creating little holes in the lawn when you lift your foot. (If your soil is especially wet or sticky, you may strip off the top layer of soil when you lift your foot, too.)

There are two reasons people use aerator shoes: to reduce lawn compaction, and to make holes to help re-seeding. When the particles in your soil are compacted, and smushed too close together, there isn’t enough room around your grasses’ roots for air. Without oxygen, your grass can’t absorb the water and nutrients your lawn needs for maximum growth; extremely compacted soil can even form a solid barrier to grass roots.

When you increase the amount of air in the soil, you increase the oxygen, water, and nutrients available to the grass. Roots can break through into new places, and more rain can find its way down into the soil. A little air near the surface of the soil can also jump-start the microorganisms that break down thatch, the mass of old dead grass and organic matter that can build up on top of the soil.

So, do aerator shoes actually work?

That depends on what you mean by “work.” Aerator shoes will definitely make hundreds of tiny holes in your lawn, providing more nooks and crannies for grass seeds to sprout in if you’re planting or overseeding a lawn. The bigger question is, are aerator shoes effective at aerating your lawn?

If you’re looking to reduce compaction, the answer is, probably not. Turf specialists recommend aerating 5% of your lawn to reduce compaction. A University of Arkansas professor did the math and found that if you use aerator shoes and take 40 steps per 10-foot-by-10-foot square of lawn, you’d only be aerating 0.04% of your lawn. By his calculations, you’d need to walk across your lawn roughly 125 times to get the aeration you’d need to reduce soil compaction effectively.

There’s also the problem that aeration spikes push the soil between the spikes together—slightly increasing compaction between the holes, according to the University of Nebraska. That’s fine if you have sandy soil that tends to shift around, but if you have sticky clay or silt soil, you’re only making things worse.

What to use instead

The solution: Use a motored “plug” or “core” aerator which you can buy or rent at The Home Depot. If your yard is very small, you can use a hand-held aerator.

Plug aerators pull out plugs of soil that are longer (3 to 6 inches) and much wider (½ to ¾ inches in diameter), so they cover a much larger surface area than the tiny spikes. They don’t add to compaction, and the soil cores on the surface help break down thatch as well.

Make sure your lawn is watered the day before you aerate so that the soil is moist, not dry or soaking wet. Otherwise, the aerator may not be able to penetrate dry, compacted soil, or may get clogged with mud.

Stay away from any buried cables, gas, or water lines in your yard. You may need to do more than one pass over your lawn to remove enough plugs to make a difference.

What to do after you aerate

After aeration, break up the cores with a rake to spread the dirt evenly over any thatch on the ground.

Then, top-dress your grass with compost to get more organic matter into the soil and improve your soil’s structure and drought-resistance. And consider putting walkways on your lawn high-traffic areas to reduce future compaction and maintenance.