Updated: Apr. 01, 2024
Liquid aeration is a convenient and effective alternative to traditional core aeration.
Labor-heavy lawn aeration isn’t a job many of us relish (including me!). However, it helps keep grass green and healthy. Loosening compacted soil allows water, air and nutrients to penetrate deeper, improving root growth. I love a quick fix, so I’ve been considering the easy-to-apply liquid aeration products that are gaining traction.
I spoke to turfgrass experts Chris Lemcke, the national technical director at Weed Man, and Professor Roch Gaussoin, Ph.D., from the Department of Agronomy and Horticulture at the University of Nebraska-Lincolnto, to find out more about this modern method and what the science tells us about why nothing — so far — beats traditional core aeration techniques.
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What is Liquid Aeration?
Unlike traditional core lawn aeration, which removes plugs of soil to reduce compaction, liquid aeration involves applying a chemical solution. The primary active ingredient is typically a wetting agent (soil surfactant) designed to promote water movement and penetration in the soil. They also often contain humates (well-decomposed dark organic matter), which can affect the soil’s structure, texture, and water-retention capacities.
Liquid Aeration Pros and Cons
Even though chemical products can’t compete with core aeration for reducing soil compaction, that doesn’t mean liquid aeration won’t benefit your lawn.
Pros
Quick and inexpensive: Compared to core aeration, which uses heavy specialist equipment, applying a liquid aerator is cheaper and easier.
Works well alongside core aeration: “When a product containing a wetting agent is used in combination with core aeration, we see positive effects,” Gaussoin says.
Increases water filtration: “Putting a wetting agent onto the soil makes the surface less hydrophobic [water-repelling],” Gaussoin says. Studies show this can allow more moisture to infiltrate the soil temporarily.
It fertilizes: Many liquid aerators contain nutrients, such as magnesium, potassium and nitrogen-containing amino acids, that can make your lawn greener.
May loosen high-sodium soils: Some liquid aerators contain soil-amending gypsum (calcium sulfate), which pushes off sodium to open up the soil. However, sodic-affected lawn soil isn’t common. “I’ve been doing this for 35 years and looked at literally thousands of soil samples, and I’ve only seen sodium-affected soils twice,” Gaussoin says.
Dethatching properties: These products often claim to contain thatch-reducing microbial microorganism boosters. However, Gaussoin cautions that they have seen very mixed results after extensive testing.
Aesthetic advantages: You won’t have unsightly holes or soil plugs on your lawn. However, Gaussoin explains that these core aeration holes fill in quickly, and the plugs can be beneficial as they degrade and redistribute into the soil.
Cons
If compacted soil is your primary concern, experts recommend core aeration or using both aeration methods together. Here’s why:
Ineffective on compaction: “Liquid aeration products will have almost no effect on compaction, especially in the short term,” Lemcke says. Gaussoin agrees. “These products aren’t extensively tested by independent agencies and when they are, the results are negative or not positive,” he says.
Quality varies: Many products make unsubstantiated claims and have vague ingredients. Look for those listing active nonionic surfactants, such as sodium lauryl sulfate.
Shallow penetration: “Liquid aeration products don’t penetrate into the soil like the depth of a coring tine, which can go down four or five inches,” Gaussoin says.
Temporary effects: “We see some limited short-term increases in water infiltration, but they don’t last very long because the plant continues to create organic matter,” Gaussoin says.
How Much Does Liquid Aeration Cost?
Expect to pay around $1 per thousand square feet of coverage to apply a liquid aerator yourself. The average cost to hire a lawn care company ranges between $150 and $200 for a single treatment.
The mechanical core aerators start at around $200. However, they can end up being a shrewder long-term investment as they do a better job, and you aren’t paying out for every treatment. You can also purchase manual lawn aerating tools that cost less or rent a lawn aerator.
How to DIY Liquid Aerate Your Lawn
Instructions vary by manufacturer, but these steps illustrate how easy it is to apply a liquid aerator to your lawn. Early fall or spring applications for cool-season grasses and late spring to early summer for warm-season grasses are best, but you can apply them anytime. If you combine it with core aeration, applying the liquid product a week before is best.
1. Water Your Lawn
A damp (not soggy) soil helps promote absorption. If there hasn’t been recent rainfall, water the lawn 24 hours before using the liquid aerator.
2. Apply the Liquid Aerator
Check the application rate for the specific product, then use a backpack, pump-up, or hose-end sprayer to apply the solution evenly across the lawn at the appropriate dilution level.
3. Water Again
To maximize liquid aeration effects, deeply water in, and wait around a week if you’re following up with core aeration.
Frequently Asked Questions
Is Liquid Aeration Worth It?
Liquid aeration can increase water penetration and temporarily boost your lawn quickly and economically, but nothing beats core aeration.
Does Liquid Aeration Work on Clay Soil?
Liquid aeration can increase water penetration in dense clay soils, helping mechanical aerator tines to penetrate compacted soils more effectively.
Can I Use Liquid Aeration After Overseeding?
It’s better to aerate before rather than after overseeding your lawn, and core aeration is more beneficial. “When you [core] aerate, you pull the plugs that break down and cover the seed, allowing for greater germination. Seeds also fall into the aerator holes and will germinate in the holes as well. This will not happen when using a liquid aeration product,” Lemcke says.
About the Experts
Chris Lemcke is the national technical director at Weed Man, a network of locally owned and operated lawn care professionals.
Roch Gaussoin, PhD, is a professor in the Department of Agronomy and Horticulture at the University of Nebraska-Lincoln. He’s an extension specialist in integrated turfgrass management and weed science.
Sources
Chris Lemcke, national technical director at Weed Man; interview, Aug. 2020.
Professor Roch Gaussoin, PhD, Department of Agronomy and Horticulture, University of Nebraska-Lincoln; video interview, Mar. 18, 2024
- Bolton, C., Tucker, K., & Henry, G. M. (2021) Comparing Liquid Aeration with Hollow Tine Cultivation [Abstract]. ASA, CSSA, SSSA International Annual Meeting, Salt Lake City, UT.
- Fleetwood, M., & Xiong, X. (2021). Improving water retention in hydrophobic soil. 2021 Turfgrass Field Day Online Golf Session. August 12, 2021. University of Arkansas System Division of Agriculture and University of Missouri Extension.
