# Excavate several inches of clay soil, and replace with what exactly?



## AGrayson84 (Jul 10, 2020)

Hi everyone! So I've had a couple older threads on here regarding my struggle with my clay soil here in Southern Maryland (United States). Basically, my entire yard all the way around the house is just nothing but compacted clay. No top soil, and there's not enough room to add top-soil over the existing clay since the ground is pretty much as high as it can be around my foundation (and I need to maintain the current grade). I don't frankly have the time nor interest in spending the next few years to improve my existing soil little by little, and I kid you not-- since this time last year, my yard has only been dry for maybe a collective 20 days. Other than that, it has stayed soggy from not going without rain for at least a week very often over the past year. The yard is a disaster once again.... all grass I've planted over the last 2 years is dead and gone, and moss, clover, and weeds are back to taking over the top layer of my soil. It's time I take some drastic measures.

I was thinking about spraying some vegetation killer to kill everything growing on my lawn, then 2 weeks or so later (I'll have to get Ms. Utility out before-hand) I'll have someone come in with an excavator and start removing several inches of this clay soil so I can replace at least those top X inches with something that has better drainage, doesn't turn to mud, and something the grass can thrive in.

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My question now is how many inches deep of the existing clay soil should I have removed, and exactly what should I be looking to replace the clay with? For instance, should I strive to remove around 5" of the current clay soil, and replace it with nothing by nice, dark top-soil? Should I try to get top-soil with organic matter mixed in, and maybe a certain amount of sand, to help with my drainage and dampness problems? Should I till in any of what I throw down, with what is left of the clay I plan on removing, or should I just dump and spread all of the new material over the existing clay?
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My yard is quite shady. It's graded very well and I've pointed all downspouts 30' away from the house using 4" corrugated piping and that didn't help at all. The current clay is just too compacted, and stays too wet 96% of the year to run an aerator thru it..... and even if I remedy the compaction the clay is just too soft when damp and when I used either the push mower or the riding mower, my grass gets mashed down into the soft clay and dies. So trying to fix the clay is just out of the question for me-- I'm really only interested in what I can do to replace some of the clay. Thanks so much everyone!!!!

EDIT: I plan to continue to grow Tall Fescue, and about 12-13k sqft of my yard is where I plan replacing the soil to continue to use as my grassy area. There will be no gardens or anything in this area.... just grass


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## Shindoman (Apr 22, 2018)

Ideally, you'd like to remove 12" of that clay. Replace it with a Sandy loam mix for turf areas. Straight good quality top soil for any areas where you will have flower or garden beds. Do it right the first time and you'll never regret it.


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## AGrayson84 (Jul 10, 2020)

Thanks so much Shindoman. So out of curiosity, why would you personally suggest to do about 12" of depth?

The reason I ask is because I have a bit of trees throughout and along my yard, so I'm worried about disturbing roots, or possibly just not being able to get that deep on many areas due to all the roots. I also have an irrigation system throughout my entire yard, buried about 12" deep.... so I'm honestly not looking to have to replace all that plumbing. I can handle re-plumbing the system myself if it came down to it, but there are about 29 sprinkler heads within the lawn area so I was really hoping I can get away with doing less.

I may have to scrap this entire idea if I did my calculations correctly. It appears that for ~13k sqft of lawn, replacing 12" of depth... I'm going to be needing around 480 cubic yards. That could be up to 48 truck-loads! And based on the cost of a cubic yard of loam (estimated prices I see on the Internet), I could be paying around a MINIMUM of $8,000 USD in getting that much loam delivered. Way, far more than I was planning on spending. I'm definitely about doing it right the first time, as you said, but if it comes down to a cost anywhere near $8k it's simply going to be too much money lol.

Thanks again for the help so far!!!


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## Easyluck (Feb 5, 2019)

Do you know how many hours of sunlight you get in the shadiest section and sunniest sections?

Also looking back at your post from last year, the soil sample you pulled sounds a little gritty when you rubbed it together. Have you ever done a soil texture analysis or a jar test to estimate %clay? Before spending that kind of money I would what to know my soil texture. A lot of Maryland has Sassafras soil (sandy clay loam). If that is your case, I don't think removing soil and replacing it with something similar will fix your issues.


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## AGrayson84 (Jul 10, 2020)

Thank you for the feedback Easyluck. I appreciate you taking the consideration of looking at my previous posts, thanks for doing that! I'd say that my shadiest sections might only see 2-4 hours of DIRECT sunlight per day. I definitely realize the shade is a contributing factor with my damp soil, but I've lived in several homes here in the Southern MD area since 1996 and none have ever had this problem. None have ever been muddy during nor immediately after rain, let alone an entire week after rain. Several yards have also had large areas just as shady as areas of my yard are... perhaps even shadier. And none of the other yards have ever been muddy like this, ever. Even during a downpour. The color of the soil has also been darker (not from black algae either hahaha!). So that's all why I'm so stuck on thinking it's just the soil at this house. There was probably never any good topsoil on this property at any point.... I think some of the yards in the neighborhood were just back-filled with nothing but what was dug out.... and from what I learned last year our neighborhood was built on what was apparently swamp land many decades back.

I never did get around to getting any sort of soil test of any sort done..... I had trouble locating anywhere to send a sample into locally, and got frustrated with the yard and just gave up on deciding anything practical could be done except replace the soil lol. So maybe I should consider getting a test of the soil texture of my yard, and test that against whatever sandy loam I have to choose from in the area to determine whether or not it's worth chasing this idea down?


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## Easyluck (Feb 5, 2019)

I would definitely get a soil test done. Waypoint analytical has an office in Leola, PA. You can send a sample USPS priority for $8-10. I would recommend the S3M test which usually cost $15-20. A soil texture test would cost a little extra.

Or you can do a simple soil jar test at home. Collect some soil, put it in a clear mason jar, add some water, shake it up, then let it sit for a day or two. The clay, silt and sand will separate and settle. Measure the distance of each and calculate the percentage. Refer to the soil texture triangle to determine soil texture. YouTube soil texture jar test

It's also possible that your house has a higher water table others in the neighborhood. If the water table is high then I would consider installing multiple French drains all throughout the yard.


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