Clay soil presents many challenges when growing grass. I am partial to centipede grass because of its low growing profile, tendency to spread and thickly blanket an area, and its general drought tolerance. But what happens when you try to grow centipede on clay soil? It all comes down to soil preparation and an understanding of the characteristics of clay.
Will Centipede Grass grow in clay soil? With proper soil preparation and treatment, Centipede grass can be successfully grown in a clay soil yard. Amending the soil with organic matter and applying quality topsoil will allow for the centipede grass to establish a hardy rooting system and prevent issues with the soil drying out or holding too much water.
Low maintenance is one of the key selling points of centipede grass but it is important to do the work upfront so that you have a soil texture and quality that will support it.
Get Your Soil Tested
Before you prepare to seed or install centipede grass plugs, you need to do some preliminary work first. When I first ran into this issue I did some research online and in my community. I spoke with neighbors and local government officials. I even took the time to talk to my local HOA.
I highly recommend that you have your soil tested if you believe that you have a high level of clay. While it can be a little disturbing when you see some of the test results, it is also enlightening to you can see and understand the composition of the soil and what you need to do.
For some reason, I have two distinctly different types of clay soil in my yard. In the back, it’s red clay soil that breaks and crumbles into small rocks when dry. In the front, however, it’s a black clay that we refer to as “gumbo clay”. I have no idea why my yard is separated this way but I had to take two radically different approaches in dealing with them.
For my front lawn, I needed to balance the pH level of the soil. Despite what others may tell you, clay soil can be acidic. Centipede grass actually prefers slightly acidic soil but not to excess. An ideal soil pH for clay is around 5 to 6 (source).
To increase the pH level of soil if it is acidic, all you have to do is mix in some lime in the fall. Over the winter, the soil pH began to even out to a more hospitable range, and by spring it was ready for grass. See, this all goes back to the importance of a soil test!
Quick And Dirty DIY Clay Soil Test For Gypsum
Gypsum is a very common soil amendment for clay. Liquid Gypsum is easy to apply and, given the right conditions, it can make a noticeable difference to clay. However, it depends on the type of clay soil that you have. There is a simple soil test that you can do on your own to determine whether or not gypsum will be beneficial:
- Roll a ball of clay into your palm, about the size of a marble.
- Drop it into a jar of water for 24 hours (use filtered or distilled water)
If the ball is disintegrated and the water is very cloudy after a day, gypsum stands to be useful in improving the clay. If, on the other hand, the ball has stayed mostly intact and the water is still relatively clear, gypsum will likely do more harm than good.
Here’s a short YouTube video where the presenter demonstrates this DIY soil test:
The point here is, adding amendments to the soil is an excellent way to improve it but you need to make sure that you are adding the right amendments so that you don’t end up doing more harm than good or just wasting your time and money.
Reduce The Density Of The Soil
If there is one improvement that you can make to clay soil that will have a lasting impact, it is to reduce the density by incorporating organic material into it.
There was never any doubt that I would go with centipede grass when we built our new home. I have had it in the past three yards where I’ve lived. To prepare clay soil for grass, mix in a healthy amount of organic material. This can be grass clippings, dead leaves, anything that will decompose (stay away from meat and dairy but kitchen scraps like veggie leftovers are actually perfect). This will allow the soil to be a bit lighter in texture and give way easily for deeper root penetration. Not to mention that it adds nutrients to the soil.
The best way to do this is with a tiller. Break up the top few inches of soil (the deeper you get, the better) and mix in as much organic material that you can get your hands on.
I made the mistake of not doing this on part of my yard and have had to develop a no-dig strategy for improving the clay under my lawn. If you have an established lawn over clay soil, you can read all about my 5-step strategy for improving clay soil without digging. Hopefully, however, you are in the preparation stage and can use the steps in this article to amend your clay soil first.
Be sure to read How To Prepare Clay Soil For Grass to understand the steps you should take before seeding or planting.
It’s important to note that clay is not all bad. The advantage that I have found is that clay holds more nutrients and moisture than other types of soil. The trick is to break it up and mix other organic material into it.
Planting Centipede Grass In Clay Soil
If you can make these amendments to the soil in the summer and fall and wait until the following spring to seed, the ground will be better prepared than doing all of this at once.
The reason is that the organic material that you add in will begin to decompose. It will (hopefully) begin attracting worms and will have reduced the compaction to a point that the soil is easier to work. Healthy soil is alive with activity but it takes times for this process to begin. Giving it a season for the microbial and worm populations to begin will kickstart the growth of your centipede seeds.
You will want to wait until the ground temperature is at or near 70 degrees. Centipede is a warm-weather grass and its seeds will not germinate well until the soil reaches this range (source).
When seeding, it is important to apply a thin layer of quality topsoil (1 inch or so). This will give the seeds a nutrient-rich environment to begin rooting before it starts working into the amended clay. Remember that seeds are like the babies of grass, they are very vulnerable in the beginning and need to be cared for in a nurturing environment. As they grow, they will become stronger and can force their roots into the harder soil below but in the beginning, we need to make it easy for them.
Spread the seed with a broadcast spreader like this one and then rake a little dirt over the seeds. Keep it watered so that it’s moist but not flooded.
Sidenote: When seeding my yard, I also did a small test pot of grass seed in my kitchen using potting soil just to test how centipede would grow with optimal soil inside next to a window with plenty of sunshine compared to outside. As it turned out, the grass outside began to breach the surface before my indoor experiment did.
Centipede grass will grow in clay soil so long as you take the time to properly prepare it and apply a thin layer of topsoil to allow the seeds to germinate. Once the grass is growing, its roots will become stronger and can begin to push down into the amended clay soil.
Centipede roots are primarily shallow so many people believe that you don’t need to worry about improving the soil more than a few inches on the top. My experience, however, has been that by incorporating organic material deep into the clay you will improve drainage as well as promoting worms and the biological activity necessary for healthy soil. In the long run, you will be well served to amend your clay soil before planting or seeding with centipede grass.
Note: To gain a more in-depth understanding of how to properly amend clay soil in your lawn be sure to read our comprehensive guide, Improve Clay Soil For New Or Existing Lawns.