Very hard clay soil

I’m digging a hole to plant a pluot tree this year, around 2-3 feet I’m hitting an extremely hard clay mixed gravel soil. The soil is so hard that i’ve been breaking it up with a pick axe. Unfortunately the drainage is very bad, I put water in the hole and it is still there after 24 hours. I was thinking I can rent a small jack hammer to break through it, although I’m not sure how deep it would go. Anybody have any ideas? I appreciate any advice.

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Every place is unique on soil but about 2-3 feet down our clay and loam give way to that same stuff. We typically use a sharp shooter shovel to get through it. If that does not work get a post hole digger with an engine which will eventually drill through it.

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An option might be,to make a raised


Yep or a mound.


Why are you digging so deep?

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I wasn’t planning to dig that deep, but once I hit it I wanted to see if I could break through the hard layer. Now I’m trying to decide if I should either leave it as it is, break through it, or build a mound above the ground surface.

This site will tell you the soil profile for any address in the USA. Web Soil Survey

It is a little awkward to use, but it does work.

The site should default to the ‘Area of Interest’ tab at the top. Then go to --> ‘Quick Navigation’; select ‘Address’ and type it in; select “AOI” box in the Area of Interest Interactive Map that appears on the right side of screen; then select ‘Soil Map’ tap from the top horizontal menu tab. This brings up the type of soils present in the area selected and you can click on them for a description of the soils, including agricultural info and drainage classification, as well as a description of the subsoil layers.

As an example, here is my soil profile:

  • Ap - 0 to 7 inches: silt loam
  • Eg - 7 to 9 inches: silt loam
  • Btg - 9 to 12 inches: silty clay loam
  • Bt1 - 12 to 20 inches: silty clay
  • Bt2 - 20 to 30 inches: silty clay
  • BCt - 30 to 36 inches: clay loam
  • C - 36 to 60 inches: clay loam

That is a very useful website, thank you. This is what I got:

  • Ap - 0 to 2 inches: sandy loam
  • ABt - 2 to 7 inches: sandy clay loam
  • Bt1 - 7 to 17 inches: gravelly sandy clay loam
  • Bt2 - 17 to 31 inches: gravelly sandy clay loam
  • C - 31 to 59 inches: very gravelly sandy loam
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Hi Kevin:

Soils vary a lot but the basic description of your soil indicates about 7 inches of topsoil. Then about 2ft of subsoil that is fairly high in clay. That is probably the layer with the slowest drainage. Below that the parent material, C horizon, sounds like it should drain fairly to very well. Even in CA most very gravelly sandy soils should drain well and maybe even too well meaning that zone holds very little water.

If the soil is level and doesn’t stay wet for long periods after rains it is probably good for fruit trees. Breaking thru the subsoil might help the tree but probably isn’t worth the effort. To really change the drainage would require ripping the soil with a huge plow to bust up the subsoil and mix it with deeper layers.

Building a mound is seldom a bad idea. But again unless the soil stays wet for long periods after big rains it is probably OK as is.


Depending on what part of the property I look at, mine looks like this :

  • Oe - 0 to 2 inches: mucky peat
  • A - 2 to 10 inches: loam
  • Btg - 10 to 32 inches: sandy clay loam
  • BCg - 32 to 39 inches: loamy sand
  • Cg1 - 39 to 46 inches: sandy clay loam
  • Cg2 - 46 to 80 inches: sand


  • Ap - 0 to 10 inches: loam
  • Btg - 10 to 32 inches: sandy clay loam
  • BCg - 32 to 39 inches: loamy sand
  • Cg1 - 39 to 46 inches: sandy clay loam
  • Cg2 - 46 to 80 inches: sand

Those look like very good soils for fruit trees. Perhaps a bit low on water holding capacity given that there is sand below 4ft. But loamy and sandy clay loams are usually excellent.

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You can also search the soil type at the OSD website for a more detailed description and a map of areas with the soil type:

I also have copy of 1978 USGS Soil Survey for my county. It has more discussion in the description. There is some discrepancy between the two, but I think both descriptions combined with my experiences so far have helped me to get a better understanding of what to expect. Still, I have encountered some mysterious anomalies that don’t fit the descriptions.

I’m less than 10 miles from the Delaware Bay/Atlantic Ocean. Makes sense that there would be a lot of sand. We have quite a few orchards around here, peach, apple, nectarine. We also have some good vineyards.


Well, I suppose I’m glad some people can get this to work

I’ve tried it several times over the last couple months. i can’t get it to work either.

Mine showed bedrock about 36" down, but we just put in a new septic system and they were still digging “red dirt” about 6’ down for the new tank! Praying is similar in other areas of the property!

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How far did you get?

Are there any nearby slopes that could have deposited erosion material there? Aside from human activity, erosion seems like the biggest cause of variation here.

I get to the “soil map” tab and get shut down with an error message about AOI selection, no matter what I do

After you select one of the “AOI” buttons in the menu, you have to select the AOI area in the map. The area will appear with diagonal shade bars it it is properly selected. Then you can go to the “soil map” tab.

OK, I’m going to guess it doesn’t work correctly on mobile devices.

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