You can grow grass in clay soil if you use these methods to improve soil drainage and overall soil health.
Growing grass in clay soil can be done if you use a variety of methods to improve the clay soil. These methods include adding organics and soil conditioners as well as mechanical methods such as core aerating and top dressing.
If you’re serious about improving your clay soil then you need to use most of, if not all of these methods. It may take several repeat efforts to build soil structure that is a healthy mix of sand, silt, clay, minerals, and organic matter that make up the ideal soil, or ‘loam’, for growing a healthy lawn.
Improving Clay Soil
Of the three particle sizes, sand, silt, and clay, the smallest is clay. This makes clay very dense which is why clay lawns are poor drainage lawns. Poor drainage lawns can drown grass roots and prevent nutrient intake. The only way to prevent your grass growing in clay from ultimately dying is to improve the clay soil using a combination of these methods:
1. Core Aeration
If you’re trying to improve clay soil in an existing lawn then Core Aerating is definitely where you need to start. A core aerator is a machine that pulls cores, several inches long, out of your lawn. Most equipment rental places have these machines available for rent.
Core aerating is where this process begins, although, by itself it won’t do much to solve your compacted soil problem. It’s simply the first step you have to take before you can get organic matter and soil amendments into your soil. After core aerating continue by using the soil amendment strategies below.
2. Top Dressing With Compost
After core aerating, top dress your lawn with compost. Core aeration combined with top dressing with compost is by far the best two things you can do to improve clay soil problems in an existing lawn. If you are only going to take two steps to fix your clay problems, then choose core aeration and top dressing.
The way it works is simple. The voids that are left over after core aerating get filled with compost. The compost also gets raked all over the surface of your lawn about a 1/4” thick. This is the best way to introduce a ton of organic matter into your soil.
If you have a cool season lawn, then after top dressing, take the next step and apply a starter fertilizer and a light seeding with a quality seed (more on seed below).
If you have a warm season lawn then you shouldn’t need to seed since most warm season lawns spread via rhizomes and/or stolon’s and will naturally fill in. Check out more on top dressing your lawn here: Top Dressing Lawn: Benefits and Advice.
3. Liquid Aeration
Chances are you’ve heard of core aeration, but you may not have heard of liquid aeration. Liquid aeration is a liquid solution that helps loosen up soil so water and nutrients can penetrate deeper into the soil. It is similar to core aeration only in core aeration sections of grass are physically removed from your lawn. In liquid aeration, instead of removing cores from your lawn, the solution works by breaking up dense particles such as clay, therefor creating a way for water and nutrients to move deeper in the soil.
My favorite product for liquid aeration is Air 8. This is a concentrate with Humic Acid as the active ingredient. I stick to the application rates on the label and mix this product in a back pack tank sprayer and spray it over the entire lawn.
Liquid aeration has a lot of benefits:
– It’s a lot easier to spray your lawn than it is to push around a core aerator.
– It’s easy to access since you can get Air 8 delivered right to your house.
– Liquid aeration is a great choice for warm season lawns that don’t want to beat up the rhizomes or stolon’s in their warm season grass that can typically occur when core aerating.
– With liquid aeration you get 100% coverage. In manual core aeration only a percentage of the lawn is being core aerated.
– Liquid aeration can be applied anytime during the growing season without the need to worry about weeds being introduced. Since there is no disturbed soil like there is in manual core aeration, you don’t have to wait until the fall (in cool season lawns) when lawn weeds are less aggressive. However, if your lawn is stressed from heat, drought, fungus, or any other reason then wait until your lawn is healthy before liquid aeration.
Overall liquid aeration is a great choice for improving clay soil for someone that doesn’t want to go through the effort of core aerating. However, if you want to really make improvements to your clay soil than I recommend core aeration combined with liquid aeration. First, core aerate, and then apply liquid aeration immediately after.
And if you want to throw everything at your clay lawn to give it the best chance for improving than I would do all of the above in the following order: Core aerate, Liquid Aerate, Top Dress, Seed and Starter Fertilizer (if you have a cool season lawn).
4. Bio Stimulants
Bio stimulants are pretty much in the same category as liquid aeration. They are liquid solutions that help loosen soil particles and promote the flow of water and nutrients.
Yard Mastery has a great selection of these solutions with information on what they specifically do. Adding a variety of bio stimulants throughout the year is just another tool at your disposal for improving clay soil. Most of these products can be applied throughout the growing season. Also, most of these are in liquid form but there is a granular option if you don’t have a back pack sprayer or just prefer application with a spreader: The Andersons 5-0-0
5. Roto Tilling
If you’re starting from scratch and don’t have a lawn yet, then now is the time to improve your clay soil! Aside from skid steers and other larger pieces of equipment, a roto tiller is your best bet for amending clay soil before seeding (or sodding). Most rental places will have roto tillers for rent. Don’t skimp out, go for one of the larger sizes.
Start out by running the rototiller over the area you are trying to plant grass. After that, spread compost over the entire area, several inches thick. Then do another pass with the roto tiller. This will work in the compost so that it mixes in with the clay soil. You can repeat this a couple of times, each time working in a couple of inches of compost.
After the compost has been mixed in, rake the area smooth, and clean up any rocks that have been churned up.
Best Grass for Clay Soil
The best grass for clay soil is Tall Fescue for cool season lawns. Tall fescue has a deep root system and is very strong. It offers strong drought tolerance, and stands up well to the heat and cold. I really like the Black Beauty Original Supreme Grass Seed Blend.
For warm season lawns Bermuda Grass is a great choice for clay soil. It’s deep rhizomes make Bermuda grass strong and resilient. Bermuda Grass is a rapid grower and has the ability to spread and fill in bare spots, as long as you keep it properly fed with a good lawn program.
Testing Lawn for Clay
You may have clay soil if you notice that fertilizers do little to nothing to green up your lawn. Assuming you’re applying fertilizers at the correct rate, you should see your lawn respond. If you’re not getting the response your looking for and your grass keeps getting weaker, it could be that clay soil is blocking nutrient absorption.
Another visual clue that you have clay soil is if you notice standing water in your lawn, or you notice bare spots that look like they’re splitting, kind of like puzzle pieces, at the surface.
Another great test is the mud shake test. It’s very simple to do at home. All you need is a small shovel and a jar. Check it out here: The Mud Shake Test.
Check Out These Posts Next
3 Product Lawn Care Program- Cool Season Lawns
Lawn Care Program for Warm Season Lawns
Top Dressing Lawn: Benefits and Advice
Lawn Dethatching: Everything You Need to Know
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Great tips! I suspect clay soil is why my fertilizer applications don’t seem to be doing anything. I’m gonna follow your advice and core aerate and top dress with compost in the fall.
I think that’s a great plan Drew! Good luck!
Stelios Doxas says
I’m going to be core-aerating and seeding some bare spots in a few days. Would you recommend liquid aerating right after core aerating? Most liquid aerator products advise to apply a month before or after seeding. Something about the danger of ‘softening’ the seed.
Good question because I’ve heard this too on only one product, other liquid aeration products that I’ve used make no mention of it. I’ve definitely had good results with seed germination applying seed right after liquid aeration. Having said that, I also top dressed the soil so the seed was in a nice layer of compost. Are you planning on top dressing those bad areas. If so I think you’d be fine.
Eric Larsen says
Is there a clay soil adviser in Kansas City KC? I live in Hazelwood Villas a retirement community. We have water runoff problems between the houses.
The clay soil has been pushed around trying to change drain paths. Some homes have water problems in their basements. There are two rows of homes separated by a slope.
With a good rain, the water from the upper homes collects and cascades downhill. Looking for some help.
Hi there Eric… So there is this site where you can look up soil conditions in your specific area..https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm… It can be a little confusing to use so you’ll have to do some clicking around. As for the problem you are describing it seems that the water is running off the slope and heading to the foundations. Honestly, that might have nothing to do with clay soil. It could just be from the volume of water during a rain storm. If that’s the case a foundation drain around the home would probably be the best solution.
Should treatments like liquid aeration and top dressing with compost be done every year? Or are they something that once they take hold, you can forget about them for a while?
Do you have any suggestions on how I can get a quick Green up? I first applied 7-0-20 on 20th of March. Then I core aerated and put down some 5-0-0 Andersons. On the 19th of April I put down some 16-0-8 Sunniland turf fertilizer and it helped with a little more green up. Do you all think I should wait or just throw down some NEXT RGS and Micro Greene on top of it? It just seems like it is taking a long time to really give me that healthy dark green.
Hi Fred, a couple of things to consider. One is I would do a soil test to check for ph especially. If you’re ph is off then your lawn won’t be able to absorb the nutrients from the fertilizers. Also, make sure you have your application rates accurate. Make sure you have the correct square footage of your lawn and check to make sure how much product you applied. Lastly, I’m not sure of your location but temps have been cold. I’m in NH and while my established grass is nice and green, the grass that is newer that I planted last year in my side yard is still very light green and barely growing. This younger grass really needs the warmer temps to get going. I’d consider all this before applying more product. Good luck!
I’m having some construction done on my house and the front yard was really trashed by heavy equipment. It’s around 1200 sq ft. I could either plant seed in the spring or could probably use sod. What’s best in the long run?
If Roto Tilling, is that all that’s needed? I assume because it’s tearing up the ground and mixing in compost, you don’t need to core/liquid aerate it?
Yes, exactly Clint! If you’re doing that, that’s the best thing you can do to incorporate organics into the soil and break up clay. You don’t have to add air 8 right After the initial mixing in of organics but in the future I’d probably add Air 8 into my annual program (twice a year).
Scott Borden says
Fred, When we moved our new house to Cape Cod I had irrigation installed, 8 inches of “loam” spread over the clay soil, sod laid down – (probably Bermuda type) and I fertilized mildly (twice) with organic fertilizer. Following our first full (hot) summer, despite irrigation, much of the lawn seemed to become infused with thatch. After the last short cut the lawn was distinctly yellow.
Early this spring: hand aeration, fertilizer and irrigation. Still, my lawn is not growing. It’s greening up (somewhat), but no need for mowing yet (late May). I plan to de-thatch next week. And apparently I can acquire unlimited amounts of compost at the local transfer station, so I thought I’d rake a lot of this “into” lawn too.
Your suggestions & comments are welcome.
Hi Scott… First off, I’d be really surprised if you had Bermuda Grass in Cape Cod. Bermuda is a warm season grass, and if somehow you had it installed in Cape Cod that could be a big part of the problem. Also, it’d be hard to believe you have a thatch problem in such a new lawn. A thatch problem is below the surface of your lawn, I wonder if what you’re looking at is dead grass along the surface. I’m curious if the sod ever really took and established itself. Since this requires a lot more detective work, feel free to email me a bunch of pics… [email protected]
A lot of your advise apples to my lawn I’m going to get a little ( what I can afford) using some of your advise, thanks I’m submitting my e-mail for suggestions and will be looking for your articles. Ken from Ohio
Good luck Ken!