Let’s be honest: Growing a beautiful lawn takes effort.
Besides mowing, watering your lawn and choosing the best types of grasses, your turf also requires aeration. (Tired of gas? These are the electric lawn mowers we recommend.)
Understanding what aeration is—and why your lawn benefits— requires a quick refresher on soil science.
Ideally, soil should contain a balance of small pores that hold water and large pores that hold oxygen. “Over time, soil becomes compacted, which limits the amount of oxygen accessible to the roots of grass,” says Clint Waltz, PhD, turfgrass specialist at the University of Georgia College of Agricultural & Environmental Sciences. “Aeration opens up the soil and creates large pores for air to fill so that roots can breathe, which stimulates new growth.”
Here’s everything else to know about when and how to aerate your lawn:
How can I tell if my lawn needs aerated?
There’s no one-size-fits all guide, but lawn care experts tend to recommend aerating every few years, especially if you have heavy soil or lots of activity on the lawn such as kids playing, pets running along a fence line, or vehicle traffic.
An easy test is to take a screwdriver and try to push it into the ground about 3 to 4 inches deep — the depth which most grass roots grow.
If it’s easy to do, your lawn is probably okay. But if you have to work to sink the screwdriver into the lawn, it’s probably time to aerate, says Waltz.
What is the best aerator for my lawn?
There are generally two kinds of aerators for sale: spike aerators and core aerators.
Without question, a core aerator (also called a hollow-tine aerator) is better for your lawn, says Waltz.
These types of aerators have hollow tines that sink into the soil and lift out small, rounded plugs a few inches long. An engine drives the tines into the soil, pulls up the plugs, and deposits them on the lawn surface.
These plugs can be left to decompose or raked up and removed. The small holes left in the lawn allow more oxygen to get to the roots.
This method also helps remove thatch, the brown layer of undecomposed grass and plant material that the grass grows up through. This thatch also inhibits air and water movement.
(Side note: If dethatching is one of your goals, don’t leave the cores to decompose, says Waltz. You'll want to remove them.)
Spike aerators (also called solid tine aerators) do not work nearly as well.
They consist of solid pieces of metal, like the tines on a fork. This type of aerator has no engine, but is instead pulled behind a riding mower or pushed across the lawn. Solid-tine aerators poke into the soil using gravity to punch holes straight down.
While they will make holes in your lawn, they're far less effective.
Solid tine aerators “actually compress the soil,” says Waltz. “It does open up some pores, but it’s not that beneficial because it compacts soil to the sides and bottom of the hole. The tines just leave ‘dimples’ in the lawn surface.” This method will also not help dethatch your lawn.
The bottom line: “You’ll get some benefits from solid tine aeration, but it’s very short-lived,” says Waltz. Core aeration is more effective and studies show the effects last longer, as well.
Do liquid aeration products work?
Liquid aeration products, which you spray on your lawn, are no substitute for core aeration in relieving soil compaction. “These products may contain a surfactant or wetting agent and nitrogen source,” says Waltz. “After you spray it on, you’ll likely see a greening response and think the product had some positive effect, but these products don’t allow more oxygen to get into the root zone.”
Ditto for those shoes with spikes on them, which compact the soil and can do even more damage.
I can't afford a core aerator. Should I rent an aerator or hire someone to aerate my lawn?
Core aerators cost thousands of dollars, so buying one is not economical for most people. While you can rent a core aerator and try to do it yourself, the equipment is cumbersome, heavy, and doesn’t turn easily, says Waltz.
This is one time you’re likely better off hiring a professional lawn service. Lawn contractors typically only charge a few hundred dollars and will get the job done quickly and efficiently.
Make sure the contractor is using a core aerator, and ask when the tines, which are replaceable, were last swapped out.
“Remember that the objective is punching holes 3 to 4 inches deep into the root zone to be most effective,” says Waltz. “If the equipment was used on 50 lawns or on sandy soil before yours,” you'll want to ask for the tines to be replaced.
“Those tines wear down fast. You want to know those 3-inch tines haven’t been worn down to 2 inches tines.”
Can you aerate a wet lawn?
You don’t want to aerate an overly dry lawn, especially on clay or silt, because the tines won’t penetrate to the depth that you need, says Waltz.
But you don’t want it sopping wet either. Instead, wait a day or so after you irrigate or you’ve had rain, then aerate.
Is too much aeration bad for your lawn?
Generally not, but it depends on the type of grass you have. (Here are our favorite types of grass for your lawn.) With grasses such as Bermuda, Kentucky blue and tall fescue, which spread by rhizome or underground stems, you probably won’t damage them by aerating frequently.
But you could overdo aeration with grasses that spread by stolons, or creeping above ground stems, such as centipede grass. “You could create too many holes and large voids that aren’t going to fill in quickly,” says Waltz.
When should I aerate my lawn?
Aerate when the grass is actively growing. For warm season grasses, that’s when the soil temperatures are 65 degrees and rising, which is roughly May to late August. For cool season grasses, that’s when soil temperatures are 55 degrees, which is mid to late spring and early to mid-fall, says Waltz.
Arricca Elin SanSone has written about health and lifestyle topics for Prevention, Country Living, Woman's Day, and more. She’s passionate about gardening, baking, reading, and spending time with the people and dogs she loves.
