It is common to have clay soil in lawns across the United States, especially if the home is a newer build.
The compacted and nutrient-deficient soil is difficult to grow grass on, but it is not as difficult as it may seem.
To grow grass in clay soil, first, you need to break up the ground. Second, test the pH and add the proper nutrients to balance it out. Next, lay down fertilizer and other additives to promote healthy soil with adequate drainage.
Luckily, having clay soil is not going to ruin your dreams of having a beautiful lawn.
If you are starting from scratch or looking to patch some grassless spots on your lawn, it will only take a few extra steps when it comes to growing a lush landscape.
This guide will take you step-by-step through the process.
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How To Grow Grass In Clay Soil
Growing grass only takes a few steps, but it is essential to follow them correctly and ensure you have the right ingredients.
You will benefit from asking your local lawn care or gardening expert to ensure that the products you choose are the best to use for your area.
Step one: Break up the clay.
Depending on the size of the area you are working with, choose a hand till or a mechanical rototill.
Using a hand till will give you more control, but it will take much longer.
See below for the guide on how to break up the clay quickly.
Step two: Test the pH and balance it out.
Heavy clay soil is often too acidic to grow anything in without treatment.
Test the pH of your clay with a pH tester, we like this one on Amazon.
Then buy a suitable additive to balance it out.
Most likely, you will need to add Lime (ground limestone) which raises the pH making the area more alkaline.
Step three: Add ingredients to create healthy soil.
It is essential to create the best conditions for plant roots if you want a healthy lawn.
Healthy soil retains moisture, provides nutrients, is soft enough for roots to grow in, and properly drains water.
There are many products on the market to obtain these results to choose according to your preferences and budget.
However, the three main products you need are organic material, nutrients, and something to help keep the clay loose and draining water.
Organic materials can include mulch, compost, peat moss, manure, rotted straw, and so much more.
There are many options for this ingredient, and it’s possible to source it from local areas or buy it from the store.
Nutrients will most likely come in the form of fertilizer.
You need to ensure you add the correct amounts of nutrients like nitrogen, phosphorus, and potassium.
There are an endless amount of fertilizers on the market, so ask your local gardening expert for the best product for your lawn.
Additives aid in loosening the clay and draining water, including:
- Sand
- Gypsum
- Organic compost
Use a mixture of any of these or choose just one.
Pro tip: Compost should not be the only product you mix into your clay, but it will give you the biggest benefit in all three categories.
Create your own using food waste from your kitchen and garden clippings, or buy it from the store.
Step four: Plant grass.
Choose to overseed or lay down sod.
Overseeding: To put down seed, you first have to choose the type of grass seed right for your area and needs.
See below for the best grasses for clay-type soil.
Check the package after choosing your grass seed or ask your local gardening expert how much seed to put down per square foot.
Throw the seed down evenly without letting the seeds pile up.
The best way to ensure even coverage is to use a drop spreader.
This is a very inexpensive tool, and it’s even cheaper to buy second-hand.
Laying Sod: Laying sod is a quick way to have a beautiful lawn.
After you have created the healthy soil and leveled it, lay down the first line of sod in a straight line.
Use a fence or a porch to help with alignment.
Starting with the second row, stager the sod squares like you would when laying brick by cutting the first square in the row in half.
Make sure to line up the edges of the square tightly without overlapping them, and do not leave any big gaps.
Fill any small gaps with additional soil.
Avoid walking on the fresh sod for at least one week.
Step five: Water the lawn.
Spray the entire lawn with at least 1/4″ inch of water after laying down the seed, be careful not to over-saturate.
The seedlings need to be kept moist during germination, so watering needs to be done before the day’s heat and directly after.
Aftercare:
- Limit or completely avoid traffic on your grass until after the seeds germinate to avoid compaction and killing the new grass.
- Continue to water every week after germination has begun.
- Aerating the lawn once a year helps break up the inevitable compaction of clay-type soils allowing for better air and water contact, which promotes a thick and luscious lawn.
For tips on aerating, including core aerating, read our article on how to aerate a lawn by hand like a pro.
How To Break Up Clay Soil For Grass Quickly
To break up clay soil quickly, acquire a mechanical rototiller, lay down your preferred additive to the top of the clay, and then make several shallow passes over the ground using the rototiller.
It is necessary to break up clay soil before growing anything in it because the clay will be very compacted and hard.
If you attempted to plant directly in the soil, the roots would have nowhere to grow, and the plant would become waterlogged due to the lack of drainage.
The clay should be fairly dry when you go to the till, or else your work will turn into a muddy mess with any clumps.
If it has rained recently, allow the ground time to dry out before beginning.
Lay down the preferred additive (we suggest gypsum) and pH balancer on the ground before tilling.
This will help to mix in the ingredients as you till, making it easier to break up the soil.
Make several shallow passes over the ground instead of one deep pass to prevent overworking the till and creating lumpy soil.
After tilling, rake the soil and level out the ground.
What Is The Best Grass Seed For Clay Soil?
Tall fescue is the best grass to plant in clay soil because it is hearty grass tolerant to heat, cold, and drought.
Many types of grass seed grow well in clay soil.
But depending on the region in which you live, you may face other challenges due to the climate, rain, or other variables outside your control.
However, there are two main categories of grass seeds: warm season and cool season.
Both groups of grasses require similar amounts of sunlight and will grow in the correctly balanced clay soil but differ greatly in temperature requirements.
You will want to choose the grass best for your region.
Warm-season grass grows during spring through fall, while cool-season grass grows from late winter until early spring.
The best grass for clay soil in warm-season climates include:
- Bermuda grass
- Buffalo grass
- Zoysia grass
Cool-season grasses include:
- Red fescue
- Tall fescue
- Kentucky bluegrass
- Perennial ryegrass
Can You Grow Grass On Clay?
Grass cannot be grown on clay unless the soil has been properly improved. Once the right additives and nutrients have been to the soil, grass can grow on clay. Clay is one of the soil types difficult to work with and requires a lot of work.
Clay soil compacts tightly, making it difficult for grass roots to anchor themselves and grow outwards.
The compaction also keeps water from draining effectively.
Without breaking up the soil and adding ingredients to add nutrients, level the pH, and keep the soil from compacting again easily, it will be nearly impossible to grow grass in clay.
However, if you put in the work, add the right products, and have some patience, you’ll grow grass in clay soil in no time.
Can You Put Topsoil Over Clay?
It’s possible to put topsoil directly over the clay. However, it will take extra maintenance. Topsoil is a perfectly good way to get grass and other plants growing quickly.
However, only putting topsoil on the clay instead of incorporating it into the ground with other organic materials will leave you with much upkeep over the years.
The clay underneath the topsoil will not drain water properly.
If you live in a dry climate, this is okay because it will retain water easily and feed the topsoil.
But if you live in a wet climate, water will not drain and potentially rot the soil.
Topsoil is also relatively expensive.
You would be better off mixing in the topsoil and incorporate it at least 4″ inches in the clay.
Are Coffee Grounds Good For Clay Soil?
Putting only coffee grounds in clay soil by themselves is not good. If the soil is not too acidic and the grounds are mixed with other components like compost, coffee grounds are good for clay soil.
Coffee grounds are high in nitrogen, one of three key nutrients for healthy plants.
Using coffee grounds in gardens is an excellent way to add nutrients, but what about clay soil?
Coffee grounds themselves do not have the same properties as healthy soil.
If you only add coffee grounds to the clay, you are not giving the soil much to work with.
Coffee grounds help keep clay soil loose and broken up, giving room for roots to grow.
Grounds are also excellent at retaining water, keeping the soil moist.
Coffee grounds, however, may make your soil too acidic.
Clay is already naturally acidic, and adding more acidity from the coffee grounds can make your lawn too acidic.
For best practice, be sure to add a pH balancer to your clay before adding anything else acidic.